To see the other types of publications on this topic, follow the link: Biofilm recovery.
Journal articles on the topic 'Biofilm recovery'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Biofilm recovery.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Oulahal, N., A. Martial-Gros, M. Bonneau, and L. J. Blum. "Combined effect of chelating agents and ultrasound on biofilm removal from stainless steel surfaces. Application to “Escherichia coli milk” and “Staphylococcus aureus milk” biofilms." Biofilms 1, no. 1 (January 2004): 65–73. http://dx.doi.org/10.1017/s1479050504001140.
Full textAbstract:
Two ultrasonic devices – flat (T1) and curved (T2) ultrasonic transducers – were developed to remove biofilms from opened and closed surfaces, respectively. The aim is to standardize biofilm removal for in situ sanitary control in the food industry. The biofilms studied in this work were model biofilms made with milk on stainless steel sheets. We have shown in a previous study that sonication could be employed to remove and resuspend biofilm consistently, with a good recovery rate, from opened surfaces. Plate counting was used to assess the efficiency of each treatment. A total removal of Escherichia coli and Staphylococcus aureus from model biofilms was obtained with T1: 10 s at 40 kHz. However, ultrasound applied with T2 (a patented curved transducer developed for closed surfaces: 10 s at 40 kHz) failed to completely remove these model biofilms: 30±7% and 66±10% for E. coli and S. aureus biofilms, respectively. In order to improve the biofilm removal from closed surfaces with T2, the effect of the application of ultrasound in combination with chelating agent preparations was investigated. The application of ultrasound with T2 in 0.05 mol EDTA or EGTA per litre dislodged the E. coli milk model biofilm, with 100±10% and 100±5% recovery yields, respectively. These results showed a synergism between ultrasonic waves and chelator preparations, i.e. the combination achieved three times the recovery rate of sonication alone (30%). However, when the same treatment was applied to the S. aureus milk model biofilm, the combined treatment with EDTA or EGTA did not significantly improve the recovery of the biofilm cells: 74±26% with EDTA at 0.025 mol/l and 41–47% with EGTA at 0.025 mol/l and 0.05 mol/l, respectively, compared with 66±10% for sonication alone. The combined treatment was in agreement with an industrial control, i.e. a good reproducible recovery of the biofilm in a few seconds (10 s) for E. coli milk biofilms but not for S. aureus biofilms.
2
Machado, Idalina, Joana Graça, Hélder Lopes, Susana Lopes, and Maria O. Pereira. "Antimicrobial Pressure of Ciprofloxacin and Gentamicin on Biofilm Development by an Endoscope-Isolated Pseudomonas aeruginosa." ISRN Biotechnology 2013 (August 28, 2013): 1–10. http://dx.doi.org/10.5402/2013/178646.
Full textAbstract:
This work aims at characterizing endoscope biofilm-isolated (PAI) and reference strain P. aeruginosa (PA) adhesion, biofilm formation and sensitivity to antibiotics. The recovery ability of the biofilm-growing bacteria subjected to intermittent antibiotic pressure (ciprofloxacin (CIP) and gentamicin (GM)), as well as the development of resistance towards antibiotics and benzalkonium chloride (BC), were also determined. The capacity of both strains to develop biofilms was greatly impaired in the presence of CIP and GM. Sanitization was not complete allowing biofilm recovery after the intermittent cycles of antibiotic pressure. The environmental pressure exerted by CIP and GM did not develop P. aeruginosa resistance to antibiotics nor cross-resistance towards BC. However, data highlighted that none of the antimicrobials led to complete biofilm eradication, allowing the recovery of the remaining adhered population possibly due to the selection of persister cells. This feature may lead to biofilm recalcitrance, reinforcement of bacterial attachment, and recolonization of other sites.
3
Gaertner, James P., Joseph A. Mendoza, Michael R. J. Forstner, and Dittmar Hahn. "Recovery of Salmonella from biofilms in a headwater spring ecosystem." Journal of Water and Health 9, no. 3 (April 26, 2011): 458–66. http://dx.doi.org/10.2166/wh.2011.173.
Full textAbstract:
Salmonellae are pathogenic bacteria often detected in waters impacted by human or animal wastes. In order to assess the fate of salmonellae in supposedly pristine environments, water and natural biofilm samples along with snails (Tarebia granifera) and crayfish (Procambarus clarkia) were collected before and up to 7 days following four precipitation events from sites within the headwater springs of Spring Lake, San Marcos, TX. The samples were analyzed for the presence of salmonellae by polymerase chain reaction (PCR) after semi-selective enrichment. Salmonellae were detected in one water sample directly after precipitation only, while detection in ten biofilm and two crayfish samples was not related to precipitation. Salmonellae were not detected in snails. Characterization of isolates by rep-PCR revealed shared profiles in water and biofilm samples, biofilm and crayfish samples, and biofilm samples collected 23 days apart. These results suggest that salmonellae are infrequently washed into this aquatic ecosystem during precipitation runoff and can potentially take up residency in biofilms which can help facilitate subsequent long-term persistence and eventual transfer through the food chain.
4
Dang, Minh-Huy, Ji-Eun Jung, Dae-Woo Lee, Kwang-Yeob Song, and Jae-Gyu Jeon. "Recovery of Acid Production in Streptococcus mutans Biofilms after Short-Term Fluoride Treatment." Caries Research 50, no. 4 (2016): 363–71. http://dx.doi.org/10.1159/000446408.
Full textAbstract:
Fluoride is commonly used as an ingredient of topical oral hygiene measures. Despite the anti-acidogenic activities of fluoride against cariogenic biofilms, the recovery of the biofilms from fluoride damage is unclear. Herein, we investigated the recovery of acid production in Streptococcus mutans biofilms after short-term or during periodic 1-min fluoride treatments. For this study, 46-hour-old S. mutans biofilms were treated with fluoride (0-2,000 ppm F-) for 1-8 min and then incubated in saliva for 0-100 min. The 74-hour-old biofilms were also periodically treated with the fluoride concentration during biofilm formation (1 min/treatment). Changes in acidogenicity and viability were determined via pH drop and colony-forming unit assays, respectively. In this study, acid production after a 1-min fluoride treatment was recovered as saliva incubation time increased, which followed a linear pattern of concentration dependence (R = 0.99, R2 = 0.98). The recovery pattern was in a biphasic pattern, with an initial rapid rate followed by a second slow recovery. Furthermore, recovery from fluoride damage was retarded in a concentration-dependent manner as treatment time increased. In periodic 1-min fluoride treatments, acid production in the biofilms was not diminished during the non-fluoride treatment period; however, it was reduced in a concentration-dependent manner during the fluoride treatment period. The viability of the biofilm cells did not change, even at high fluoride concentrations. Collectively, our results suggest that brief fluoride treatment does not sustain anti-acidogenic activity against S. mutans in biofilms since the damage is recoverable with time.
5
Jiang, Qingru, Veera Kainulainen, Iva Stamatova, Sok-Ja Janket, Jukka H. Meurman, and Riitta Korpela. "Mouthwash Effects on LGG-Integrated Experimental Oral Biofilms." Dentistry Journal 8, no. 3 (September 1, 2020): 96. http://dx.doi.org/10.3390/dj8030096.
Full textAbstract:
In order to investigate the effects of mouthwashes on oral biofilms with probiotics, we compared in biofilms the susceptibility to mouthwashes of probiotic Lactobacillus rhamnosus GG (LGG) and oral pathogens Streptococcus mutans, Streptococcus sanguinis, and Candida albicans. We also evaluated these pathogens’ susceptibility to the mouthwashes and their recovery after mouthwash-rinsing in biofilms with/without LGG. First, 1-day-/3-day-old LGG-integrated multi-species biofilms were exposed for 1 min to mouthwashes containing chlorhexidine, essential oils, or amine fluoride/stannous fluoride. Cells were plate-counted and relative survival rates (RSRs) of LGG and pathogens calculated. Second, 1-day-/3-day-old multispecies biofilms with and without LGG were exposed for 1 min to mouthwashes; cells were plate-counted and the pathogens’ RSRs were calculated. Third, 1-day-old biofilms were treated for 1 min with mouthwashes. Cells were plate-counted immediately and after 2-day cultivation. Recovery rates of pathogens were calculated and compared between biofilms with/without LGG. Live/Dead® staining served for structural analyses. Our results showed that RSRs of LGG were insignificantly smaller than those of pathogens in both 1-day and 3-day biofilms. No significant differences appeared in pathogens’ RSRs and recovery rates after treatment between biofilms with/without LGG. To conclude, biofilm LGG was susceptible to the mouthwashes; but biofilm LGG altered neither the mouthwash effects on oral pathogens nor affected their recovery.
6
Řičicová, Markéta, Soňa Kucharíková, Hélène Tournu, Jelle Hendrix, Helena Bujdáková, Johan Van Eldere, Katrien Lagrou, and Patrick Van Dijck. "Candida albicans biofilm formation in a new in vivo rat model." Microbiology 156, no. 3 (March 1, 2010): 909–19. http://dx.doi.org/10.1099/mic.0.033530-0.
Full textAbstract:
Device-associated microbial growth, including Candida biofilms, represents more than half of all human microbial infections and, despite a relatively small risk of implant-associated diseases, this type of infection usually leads to high morbidity, increased health-care costs and prolonged antimicrobial therapy. Animal models are needed to elucidate the complex host–pathogen interactions that occur during the development of attached and structured biofilm populations. We describe here a new in vivo model to study Candida biofilm, based on the avascular implantation of small catheters in rats. Polyurethane biomaterials challenged with Candida cells were placed underneath the skin of immunosuppressed animals following only minor surgery. The model allowed the study of up to ten biofilms at once, and the recovery of mature biofilms from 2 days after implantation. The adhering inoculum was adjusted to the standard threshold of positive diagnosis of fungal infection in materials recovered from patients. Wild-type biofilms were mainly formed of hyphal cells, and they were unevenly distributed across the catheter length as observed in infected materials in clinical cases. The hyphal multilayered structure of the biofilms of wild-type strains was observed by confocal microscopy and compared to the monolayer of yeast or hyphal cells of two well-known biofilm-deficient strains, efg1Δ/efg1Δ cph1Δ/cph1Δ and bcr1Δ/bcr1Δ, respectively. The subcutaneous Candida biofilm model relies on the use of implanted catheters with accessible, fast and minor surgery to the animals. This model can be used to characterize the ability of antimicrobial agents to eliminate biofilms, and to evaluate the prophylactic effect of antifungal drugs and biomaterial coatings.
7
Boltz, Joshua P., Barth F. Smets, Bruce E. Rittmann, Mark C. M. van Loosdrecht, Eberhard Morgenroth, and Glen T. Daigger. "From biofilm ecology to reactors: a focused review." Water Science and Technology 75, no. 8 (February 2, 2017): 1753–60. http://dx.doi.org/10.2166/wst.2017.061.
Full textAbstract:
Biofilms are complex biostructures that appear on all surfaces that are regularly in contact with water. They are structurally complex, dynamic systems with attributes of primordial multicellular organisms and multifaceted ecosystems. The presence of biofilms may have a negative impact on the performance of various systems, but they can also be used beneficially for the treatment of water (defined herein as potable water, municipal and industrial wastewater, fresh/brackish/salt water bodies, groundwater) as well as in water stream-based biological resource recovery systems. This review addresses the following three topics: (1) biofilm ecology, (2) biofilm reactor technology and design, and (3) biofilm modeling. In so doing, it addresses the processes occurring in the biofilm, and how these affect and are affected by the broader biofilm system. The symphonic application of a suite of biological methods has led to significant advances in the understanding of biofilm ecology. New metabolic pathways, such as anaerobic ammonium oxidation (anammox) or complete ammonium oxidation (comammox) were first observed in biofilm reactors. The functions, properties, and constituents of the biofilm extracellular polymeric substance matrix are somewhat known, but their exact composition and role in the microbial conversion kinetics and biochemical transformations are still to be resolved. Biofilm grown microorganisms may contribute to increased metabolism of micro-pollutants. Several types of biofilm reactors have been used for water treatment, with current focus on moving bed biofilm reactors, integrated fixed-film activated sludge, membrane-supported biofilm reactors, and granular sludge processes. The control and/or beneficial use of biofilms in membrane processes is advancing. Biofilm models have become essential tools for fundamental biofilm research and biofilm reactor engineering and design. At the same time, the divergence between biofilm modeling and biofilm reactor modeling approaches is recognized.
8
Reiter, Keli Cristine, Gustavo Enck Sambrano, Bárbara Villa, Thiago Galvão da Silva Paim, Caio Fernando de Oliveira, and Pedro Alves d'Azevedo. "Rifampicin fails to eradicate mature biofilm formed by methicillin-resistant Staphylococcus aureus." Revista da Sociedade Brasileira de Medicina Tropical 45, no. 4 (August 2012): 471–74. http://dx.doi.org/10.1590/s0037-86822012000400011.
Full textAbstract:
INTRODUCTION: Antimicrobial activity on biofilms depends on their molecular size, positive charges, permeability coefficient, and bactericidal activity. Vancomycin is the primary choice for methicillin-resistant Staphylococcus aureus (MRSA) infection treatment; rifampicin has interesting antibiofilm properties, but its effectivity remains poorly defined. METHODS: Rifampicin activity alone and in combination with vancomycin against biofilm-forming MRSA was investigated, using a twofold serial broth microtiter method, biofilm challenge, and bacterial count recovery. RESULTS: Minimal inhibitory concentration (MIC) and minimal bactericidal concentration for vancomycin and rifampicin ranged from 0.5 to 1mg/l and 0.008 to 4mg/l, and from 1 to 4mg/l and 0.06 to 32mg/l, respectively. Mature biofilms were submitted to rifampicin and vancomycin exposure, and minimum biofilm eradication concentration ranged from 64 to 32,000 folds and from 32 to 512 folds higher than those for planktonic cells, respectively. Vancomycin (15mg/l) in combination with rifampicin at 6 dilutions higher each isolate MIC did not reach in vitro biofilm eradication but showed biofilm inhibitory capacity (1.43 and 0.56log10 CFU/ml reduction for weak and strong biofilm producers, respectively; p<0.05). CONCLUSIONS: In our setting, rifampicin alone failed to effectively kill biofilm-forming MRSA, demonstrating stronger inability to eradicate mature biofilm compared with vancomycin.
9
Martinez, Keith A., Ryan D. Kitko, J. Patrick Mershon, Haley E. Adcox, Kotiba A. Malek, Melanie B. Berkmen, and Joan L. Slonczewski. "Cytoplasmic pH Response to Acid Stress in Individual Cells of Escherichia coli and Bacillus subtilis Observed by Fluorescence Ratio Imaging Microscopy." Applied and Environmental Microbiology 78, no. 10 (March 16, 2012): 3706–14. http://dx.doi.org/10.1128/aem.00354-12.
Full textAbstract:
ABSTRACTThe ability ofEscherichia coliandBacillus subtilisto regulate their cytoplasmic pH is well studied in cell suspensions but is poorly understood in individual adherent cells and biofilms. We observed the cytoplasmic pH of individual cells using ratiometric pHluorin. A standard curve equating the fluorescence ratio with pH was obtained by perfusion at a range of external pH 5.0 to 9.0, with uncouplers that collapse the transmembrane pH difference. Adherent cells were acid stressed by switching the perfusion medium from pH 7.5 to pH 5.5. TheE. colicytoplasmic pH fell to a value that varied among individual cells (range of pH 6.2 to 6.8), but a majority of cells recovered (to pH 7.0 to 7.5) within 2 min. In anE. colibiofilm, cells shifted from pH 7.5 to pH 5.5 failed to recover cytoplasmic pH. Following a smaller shift (from pH 7.5 to pH 6.0), most biofilm cells recovered fully, although the pH decreased further than that of isolated adherent cells, and recovery took longer (7 min or longer). Some biofilm cells began to recover pH and then failed, a response not seen in isolated cells.B. subtiliscells were acid shifted from pH 7.5 to pH 6.0. InB. subtilis, unlike the case withE. coli, cytoplasmic pH showed no “overshoot” but fell to a level that was maintained. This level of cytoplasmic pH post-acid shift varied among individualB. subtiliscells (range of pH, 7.0 to 7.7). Overall, the cytoplasmic pHs of individual bacteria show important variation in the acid stress response, including novel responses in biofilms.
10
Delavar, Mojtaba Aghajani, and Junye Wang. "Lattice Boltzmann Method in Modeling Biofilm Formation, Growth and Detachment." Sustainability 13, no. 14 (July 16, 2021): 7968. http://dx.doi.org/10.3390/su13147968.
Full textAbstract:
Biofilms are a complex and heterogeneous aggregation of multiple populations of microorganisms linked together by their excretion of extracellular polymer substances (EPS). Biofilms can cause many serious problems, such as chronic infections, food contamination and equipment corrosion, although they can be useful for constructive purposes, such as in wastewater treatment, heavy metal removal from hazardous waste sites, biofuel production, power generation through microbial fuel cells and microbially enhanced oil recovery; however, biofilm formation and growth are complex due to interactions among physicochemical and biological processes under operational and environmental conditions. Advanced numerical modeling techniques using the lattice Boltzmann method (LBM) are enabling the prediction of biofilm formation and growth and microbial community structures. This study is the first attempt to perform a general review on major contributions to LBM-based biofilm models, ranging from pioneering efforts to more recent progress. We present our understanding of the modeling of biofilm formation, growth and detachment using LBM-based models and present the fundamental aspects of various LBM-based biofilm models. We describe how the LBM couples with cellular automata (CA) and individual-based model (IbM) approaches and discuss their applications in assessing the spatiotemporal distribution of biofilms and their associated parameters and evaluating bioconversion efficiency. Finally, we discuss the main features and drawbacks of LBM-based biofilm models from ecological and biotechnological perspectives and identify current knowledge gaps and future research priorities.
11
Redanz, Sylvio, Andreas Enz, Andreas Podbielski, and Philipp Warnke. "Targeted Swabbing of Implant-Associated Biofilm Formation—A Staining-Guided Sampling Approach for Optimizing Routine Microbiological Diagnostics." Diagnostics 11, no. 6 (June 4, 2021): 1038. http://dx.doi.org/10.3390/diagnostics11061038.
Full textAbstract:
Background: Swabbing of implants removed from potentially infected sites represents a time saving and ubiquitously applicable alternative to sonication approaches. The latter bears an elevated risk of processing related contaminations due to the high number of handling steps. Since biofilms are usually invisible to the naked eye, adequate swabbing relies on the chance of hitting the colonized area on the implant. A targeted directed swabbing approach could overcome this detriment. Method: Three dyes were tested at different concentrations for their toxicity on biofilm-associated cells of S. epidermidis, the species most frequently identified as a causative agent of implant-associated infections. Results: Malachite green (0.2%) delivered the highest bacterial recovery rates combined with the best results in biofilm visualization. Its suitability for diagnostic approaches was demonstrated for smooth and rough implant surfaces. Biofilm-covered areas were successfully visualized. Conclusion: Subsequent targeted swab-sampling resulted in a significantly increased bacterial recovery rate compared to a dye-free “random swabbing” diagnostic approach.
12
Dzubakova, Katharine, Hannes Peter, Enrico Bertuzzo, Carmelo Juez, Mário J. Franca, Andrea Rinaldo, and Tom J. Battin. "Environmental heterogeneity promotes spatial resilience of phototrophic biofilms in streambeds." Biology Letters 14, no. 10 (October 2018): 20180432. http://dx.doi.org/10.1098/rsbl.2018.0432.
Full textAbstract:
The loss of environmental heterogeneity threatens biodiversity and ecosystem functioning. It is therefore important to understand the relationship between environmental heterogeneity and spatial resilience as the capacity of ecological communities embedded in a landscape matrix to reorganize following disturbance. We experimented with phototrophic biofilms colonizing streambed landscapes differing in spatial heterogeneity and exposed to flow-induced disturbance. We show how streambed roughness and related features promote growth-related trait diversity and the recovery of biofilms towards carrying capacity (CC) and spatial resilience. At the scale of streambed landscapes, roughness and exposure to water flow promoted biofilm CC and growth trait diversity. Structural equation modelling identified roughness, post-disturbance biomass and a ‘neighbourhood effect’ to drive biofilm CC. Our findings suggest that the environment selecting for adaptive capacities prior to disturbance (that is, memory effects) and biofilm connectivity into spatial networks (that is, mobile links) contribute to the spatial resilience of biofilms in streambed landscapes. These findings are critical given the key functions biofilms fulfil in streams, now increasingly experiencing shifts in sedimentary and hydrological regimes.
13
Ali, Islam A. A., Becky P. K. Cheung, JukkaP Matinlinna, Celine M. Lévesque, and Prasanna Neelakantan. "Trans-cinnamaldehyde potently kills Enterococcus faecalis biofilm cells and prevents biofilm recovery." Microbial Pathogenesis 149 (December 2020): 104482. http://dx.doi.org/10.1016/j.micpath.2020.104482.
Full text
14
Virdi, Ravleen, Melissa E. Lowe, Grant J. Norton, Stephanie N. Dawrs, Nabeeh A. Hasan, L. Elaine Epperson, Cody M. Glickman, et al. "Lower Recovery of Nontuberculous Mycobacteria from Outdoor Hawai’i Environmental Water Biofilms Compared to Indoor Samples." Microorganisms 9, no. 2 (January 22, 2021): 224. http://dx.doi.org/10.3390/microorganisms9020224.
Full textAbstract:
Nontuberculous mycobacteria (NTM) are environmental organisms that can cause opportunistic pulmonary disease with species diversity showing significant regional variation. In the United States, Hawai’i shows the highest rate of NTM pulmonary disease. The need for improved understanding of NTM reservoirs led us to identify NTM from patient respiratory specimens and compare NTM diversity between outdoor and indoor locations in Hawai’i. A total of 545 water biofilm samples were collected from 357 unique locations across Kaua’i (n = 51), O’ahu (n = 202), Maui (n = 159), and Hawai’i Island (n = 133) and divided into outdoor (n = 179) or indoor (n = 366) categories. rpoB sequence analysis was used to determine NTM species and predictive modeling applied to develop NTM risk maps based on geographic characteristics between environments. M. chimaera was frequently identified from respiratory and environmental samples followed by M. chelonae and M. abscessus; yet significantly less NTM were consistently recovered from outdoor compared to indoor biofilms, as exemplified by showerhead biofilm samples. While the frequency of M. chimaera recovery was comparable between outdoor and indoor showerhead biofilms, phylogenetic analyses demonstrate similar rpoB gene sequences between all showerhead and respiratory M. chimaera isolates, supporting outdoor and indoor environments as possible sources for pulmonary M. chimaera infections.
15
Finelli, Antonio, Claude V. Gallant, Keith Jarvi, and Lori L. Burrows. "Use of In-Biofilm Expression Technology To Identify Genes Involved in Pseudomonas aeruginosa Biofilm Development." Journal of Bacteriology 185, no. 9 (May 1, 2003): 2700–2710. http://dx.doi.org/10.1128/jb.185.9.2700-2710.2003.
Full textAbstract:
ABSTRACT Mature Pseudomonas aeruginosa biofilms form complex three-dimensional architecture and are tolerant of antibiotics and other antimicrobial compounds. In this work, an in vivo expression technology system, originally designed to study virulence-associated genes in complex mammalian environments, was used to identify genes up-regulated in P. aeruginosa grown to a mature (5-day) biofilm. Five unique cloned promoters unable to promote in vitro growth in the absence of purines after recovery from the biofilm environment were identified. The open reading frames downstream of the cloned promoter regions were identified, and knockout mutants were generated. Insertional mutation of PA5065, a homologue of Escherichia coli ubiB, was lethal, while inactivation of PA0240 (a porin homologue), PA3710 (a putative alcohol dehydrogenase), and PA3782 (a homologue of the Streptomyces griseus developmental regulator adpA) had no effect on planktonic growth but caused defects in biofilm formation in static and flowing systems. In competition experiments, mutants demonstrated reduced fitness compared with the parent strain, comprising less than 0.0001% of total biofilm cells after 5 days. Therefore, using in-biofilm expression technology, we have identified novel genes that do not affect planktonic growth but are important for biofilm formation, development, and fitness.
16
Ai, Chenbing, Shanshan Hou, Zhang Yan, Xiaoya Zheng, Charles Amanze, Liyuan Chai, Guanzhou Qiu, and Weimin Zeng. "Recovery of Metals from Acid Mine Drainage by Bioelectrochemical System Inoculated with a Novel Exoelectrogen, Pseudomonas sp. E8." Microorganisms 8, no. 1 (December 24, 2019): 41. http://dx.doi.org/10.3390/microorganisms8010041.
Full textAbstract:
Acid mine drainage (AMD) is a typical source of environmental pollution ascribing to its characteristics of high acidity and heavy metal content. Currently, most strategies for AMD treatment merely focus on metal removal rather than metal recovery. However, bioelectrochemical system (BES) is a promising technology to simultaneously remove and recover metal ions from AMD. In this study, both cupric ion and cadmium ion in simulated AMD were effectively recovered by BES inoculated with a novel exoelectrogen, Pseudomonas sp. E8, that was first isolated from the anodic electroactive biofilm of a microbial fuel cell (MFC) in this study. Pseudomonas sp. E8 is a facultative anaerobic bacterium with a rod shape, 0.43–0.47 μm wide, and 1.10–1.30 μm long. Pseudomonas sp. E8 can agglomerate on the anode surface to form a biofilm in the single-chamber MFC using diluted Luria-Bertani (LB) medium as an energy substrate. A single-chamber MFC containing the electroactive Pseudomonas sp. E8 biofilms has a maximum output voltage of 191 mV and a maximum power density of 70.40 mW/m2, which is much higher than those obtained by most other exoelectrogenic strains in the genus of Pseudomonas. Almost all the Cu2+ (99.95% ± 0.09%) and Cd2+ (99.86% ± 0.04%) in simulated AMD were selectively recovered by a microbial fuel cell (MFC) and a microbial electrolysis cell (MEC). After the treatment with BES, the high concentrations of Cu2+(184.78 mg/L), Cd2+(132.25 mg/L), and total iron (49.87 mg/L) in simulated AMD were decreased to 0.02, 0.19, and 0 mg/L, respectively. Scanning electron micrograph (SEM), energy dispersive X-ray spectrometry (EDXS) and X-ray diffraction (XRD) analysis indicate that the Cu2+ and Cd2+ in simulated AMD were selectively recovered by microbial electrochemical reduction as Cu0 (together with trace amounts of Cu2O) or Cd0 on the cathode surface. Collectively, data suggest that Pseudomonas sp. E8 has great potential for AMD treatment and metal recovery.
17
Romani, Anna M., and Sergi Sabater. "Metabolism recovery of a stromatolitic biofilm after drought in a Mediterranean stream fig: 3." Fundamental and Applied Limnology 140, no. 2 (September 25, 1997): 261–71. http://dx.doi.org/10.1127/archiv-hydrobiol/140/1997/261.
Full text
18
Lim, Dong-Hee, Jai-Young Lee, and Christian M. Lastoskie. "Ability of Beijerinckia indica to degrade phenanthrene and reduce hydraulic conductivity." Water Science and Technology 62, no. 12 (December 1, 2010): 2953–60. http://dx.doi.org/10.2166/wst.2010.345.
Full textAbstract:
This study evaluates the ability of Beijerinckia indica (B. indica) as a biomaterial for aerobic biofilm barriers. B. indica's ability to remove phenanthrene was measured using a two-phase partitioning bioreactor. Approximately 500 mg/L of phenanthrene was gradually removed over a two week period under aerobic conditions of the bioreactor. B. indica's ability to reduce hydraulic conductivity was evaluated using rigid wall soil columns inoculated with the bacteria. B. indica formed a large quantity of strongly adhesive biofilm among soil particles, reducing the hydraulic conductivity in the soil columns by 2 or 3 orders of magnitude. To assess recovery of the biofilm, the formed biofilm was purposely destroyed by introducing landfill leachate into the soil columns. The biofilm recovery test showed that the hydraulic conductivity increased after leachate introduction. However, re-permeation of nutrient solution restored the permeability to its original lower value, which suggests a full recovery of the damaged biofilm. This study suggests that B. indica may be used as a possible biomaterial for aerobic biofilm barriers for the removal of phenanthrene from groundwater, provided that sufficient substrate and electron acceptor are provided to the treatment system.
19
Mootz, Joe M., Cheryl L. Malone, Lindsey N. Shaw, and Alexander R. Horswill. "Staphopains Modulate Staphylococcus aureus Biofilm Integrity." Infection and Immunity 81, no. 9 (June 24, 2013): 3227–38. http://dx.doi.org/10.1128/iai.00377-13.
Full textAbstract:
ABSTRACTStaphylococcus aureusis a known cause of chronic biofilm infections that can reside on medical implants or host tissue. Recent studies have demonstrated an important role for proteinaceous material in the biofilm structure. TheS. aureusgenome encodes many secreted proteases, and there is growing evidence that these enzymes have self-cleavage properties that alter biofilm integrity. However, the specific contribution of each protease and mechanism of biofilm modulation is not clear. To address this issue, we utilized a sigma factor B (ΔsigB) mutant where protease activity results in a biofilm-negative phenotype, thereby creating a condition where the protease(s) responsible for the phenotype could be identified. Using a plasma-coated microtiter assay, biofilm formation was restored to the ΔsigBmutant through the addition of the cysteine protease inhibitor E-64 or by using Staphostatin inhibitors that specifically target the extracellular cysteine proteases SspB and ScpA (called Staphopains). Through construction of gene deletion mutants, we determined that ansspB scpAdouble mutant restored ΔsigBbiofilm formation, and this recovery could be replicated in plasma-coated flow cell biofilms. Staphopain levels were also found to be decreased under biofilm-forming conditions, possibly allowing biofilm establishment. The treatment ofS. aureusbiofilms with purified SspB or ScpA enzyme inhibited their formation, and ScpA was also able to disperse an established biofilm. The antibiofilm properties of ScpA were conserved acrossS. aureusstrain lineages. These findings suggest an underappreciated role of the SspB and ScpA cysteine proteases in modulatingS. aureusbiofilm architecture.
20
Bester, Elanna, Otini Kroukamp, Gideon M. Wolfaardt, Leandro Boonzaaier, and Steven N. Liss. "Metabolic Differentiation in Biofilms as Indicated by Carbon Dioxide Production Rates." Applied and Environmental Microbiology 76, no. 4 (December 18, 2009): 1189–97. http://dx.doi.org/10.1128/aem.01719-09.
Full textAbstract:
ABSTRACT The measurement of carbon dioxide production rates as an indication of metabolic activity was applied to study biofilm development and response of Pseudomonas sp. biofilms to an environmental disturbance in the form of a moving air-liquid interface (i.e., shear). A differential response in biofilm cohesiveness was observed after bubble perturbation, and the biofilm layers were operationally defined as either shear-susceptible or non-shear-susceptible. Confocal laser scanning microscopy and image analysis showed a significant reduction in biofilm thickness and biomass after the removal of the shear-susceptible biofilm layer, as well as notable changes in the roughness coefficient and surface-to-biovolume ratio. These changes were accompanied by a 72% reduction of whole-biofilm CO2 production; however, the non-shear-susceptible region of the biofilm responded rapidly after the removal of the overlying cells and extracellular polymeric substances (EPS) along with the associated changes in nutrient and O2 flux, with CO2 production rates returning to preperturbation levels within 24 h. The adaptable nature and the ability of bacteria to respond to environmental conditions were further demonstrated by the outer shear-susceptible region of the biofilm; the average CO2 production rate of cells from this region increased within 0.25 h from 9.45 ± 5.40 fmol of CO2·cell−1·h−1 to 22.6 ± 7.58 fmol of CO2·cell−1·h−1 when cells were removed from the biofilm and maintained in suspension without an additional nutrient supply. These results also demonstrate the need for sufficient monitoring of biofilm recovery at the solid substratum if mechanical methods are used for biofouling control.
21
LEE, L. "Biofilm morphology and nitrification activities: recovery of nitrifying biofilm particles covered with heterotrophic outgrowth." Bioresource Technology 95, no. 2 (November 2004): 209–14. http://dx.doi.org/10.1016/j.biortech.2003.05.004.
Full text
22
Lourenço, António, Aitor de Las Heras, Mariela Scortti, Jose Vazquez-Boland, Joseph F. Frank, and Luisa Brito. "Comparison of Listeria monocytogenes Exoproteomes from Biofilm and Planktonic State: Lmo2504, a Protein Associated with Biofilms." Applied and Environmental Microbiology 79, no. 19 (July 26, 2013): 6075–82. http://dx.doi.org/10.1128/aem.01592-13.
Full textAbstract:
ABSTRACTThe food-borne pathogenListeria monocytogenesis the causative agent of the severe human and animal disease listeriosis. The persistence of this bacterium in food processing environments is mainly attributed to its ability to form biofilms. The search for proteins associated with biofilm formation is an issue of great interest, with most studies targeting the whole bacterial proteome. Nevertheless, exoproteins constitute an important class of molecules participating in various physiological processes, such as cell signaling, pathogenesis, and matrix remodeling. The aim of this work was to quantify differences in protein abundance between exoproteomes from a biofilm and from the planktonic state. For this, two field strains previously evaluated to be good biofilm producers (3119 and J311) were used, and a procedure for the recovery of biofilm exoproteins was optimized. Proteins were resolved by two-dimensional difference gel electrophoresis and identified by electrospray ionization-tandem mass spectrometry. One of the proteins identified in higher abundance in the biofilm exoproteomes of both strains was the putative cell wall binding protein Lmo2504. A mutant strain with deletion of the gene for Lmo2504 was produced (3119Δlmo2504), and its biofilm-forming ability was compared to that of the wild type using the crystal violet and the ruthenium red assays as well as scanning electron microscopy. The results confirmed the involvement of Lmo2504 in biofilm formation, as strain 3119Δlmo2504showed a significantly (P< 0.05) lower biofilm-forming ability than the wild type. The identification of additional exoproteins associated with biofilm formation may lead to new strategies for controlling this pathogen in food processing facilities.
23
Daddi Oubekka, S., R. Briandet, M. P. Fontaine-Aupart, and K. Steenkeste. "Correlative Time-Resolved Fluorescence Microscopy To Assess Antibiotic Diffusion-Reaction in Biofilms." Antimicrobial Agents and Chemotherapy 56, no. 6 (March 26, 2012): 3349–58. http://dx.doi.org/10.1128/aac.00216-12.
Full textAbstract:
ABSTRACTThe failure of antibiotics to inactivatein vivopathogens organized in biofilms has been shown to trigger chronic infections. In addition to mechanisms involving specific genetic or physiological cell properties, antibiotic sorption and/or reaction with biofilm components may lessen the antibiotic bioavailability and consequently decrease their efficiency. To assess locally and accurately the antibiotic diffusion-reaction, we used for the first time a set of advanced fluorescence microscopic tools (fluorescence recovery after photobleaching, fluorescence correlation spectroscopy, and fluorescence lifetime imaging) that offer a spatiotemporal resolution not available with the commonly used time-lapse confocal imaging method. This set of techniques was used to characterize the dynamics of fluorescently labeled vancomycin in biofilms formed by twoStaphylococcus aureushuman isolates. We demonstrate that, at therapeutic concentrations of vancomycin, the biofilm matrix was not an obstacle to the diffusion-reaction of the antibiotic that can reach all cells through the biostructure.
24
Habash, Marc B., Amber J. Park, Emily C. Vis, Robert J. Harris, and Cezar M. Khursigara. "Synergy of Silver Nanoparticles and Aztreonam against Pseudomonas aeruginosa PAO1 Biofilms." Antimicrobial Agents and Chemotherapy 58, no. 10 (July 21, 2014): 5818–30. http://dx.doi.org/10.1128/aac.03170-14.
Full textAbstract:
ABSTRACTPathogenic bacterial biofilms, such as those found in the lungs of patients with cystic fibrosis (CF), exhibit increased antimicrobial resistance, due in part to the inherent architecture of the biofilm community. The protection provided by the biofilm limits antimicrobial dispersion and penetration and reduces the efficacy of antibiotics that normally inhibit planktonic cell growth. Thus, alternative antimicrobial strategies are required to combat persistent infections. The antimicrobial properties of silver have been known for decades, but silver and silver-containing compounds have recently seen renewed interest as antimicrobial agents for treating bacterial infections. The goal of this study was to assess the efficacy of citrate-capped silver nanoparticles (AgNPs) of various sizes, alone and in combination with the monobactam antibiotic aztreonam, to inhibitPseudomonas aeruginosaPAO1 biofilms. Among the different sizes of AgNPs examined, 10-nm nanoparticles were most effective in inhibiting the recovery ofP. aeruginosabiofilm cultures and showed synergy of inhibition when combined with sub-MIC levels of aztreonam. Visualization of biofilms treated with combinations of 10-nm AgNPs and aztreonam indicated that the synergistic bactericidal effects are likely caused by better penetration of the small AgNPs into the biofilm matrix, which enhances the deleterious effects of aztreonam against the cell envelope ofP. aeruginosawithin the biofilms. These data suggest that small AgNPs synergistically enhance the antimicrobial effects of aztreonam againstP. aeruginosain vitro, and they reveal a potential role for combinations of small AgNPs and antibiotics in treating patients with chronic infections.
25
WANG, RONG, NORASAK KALCHAYANAND, DAVID A. KING, BRANDON E. LUEDTKE, JOSEPH M. BOSILEVAC, and TERRANCE M. ARTHUR. "Biofilm Formation and Sanitizer Resistance of Escherichia coli O157:H7 Strains Isolated from “High Event Period” Meat Contamination†." Journal of Food Protection 77, no. 11 (November 1, 2014): 1982–87. http://dx.doi.org/10.4315/0362-028x.jfp-14-253.
Full textAbstract:
In the meat industry, a “high event period” (HEP) is defined as a time period during which commercial meat plants experience a higher than usual rate of Escherichia coli O157:H7 contamination. Genetic analysis indicated that within a HEP, most of the E. coli O157:H7 strains belong to a singular dominant strain type. This was in disagreement with the current beef contamination model stating that contamination occurs when incoming pathogen load on animal hides, which consists of diverse strain types of E. coli O157:H7, exceeds the intervention capacity. Thus, we hypothesize that the HEP contamination may be due to certain in-plant colonized E. coli O157:H7 strains that are better able to survive sanitization through biofilm formation. To test our hypothesis, a collection of 45 E. coli O157:H7 strains isolated from HEP beef contamination incidents and a panel of 47 E. coli O157:H7 strains of diverse genetic backgrounds were compared for biofilm formation and sanitizer resistance. Biofilm formation was tested on 96-well polystyrene plates for 1 to 6 days. Biofilm cell survival and recovery growth after sanitization were compared between the two strain collections using common sanitizers, including quaternary ammonium chloride, chlorine, and sodium chlorite. No difference in “early stage” biofilms was observed between the two strain collections after incubation at 22 to 25°C for 1 or 2 days. However, the HEP strains demonstrated significantly higher potency of “mature” biofilm formation after incubation for 4 to 6 days. Biofilms of the HEP strains also exhibited significantly stronger resistance to sanitization. These data suggest that biofilm formation and sanitization resistance could have a role in HEP beef contamination by E. coli O157:H7, which highlights the importance of proper and complete sanitization of food contact surfaces and food processing equipment in commercial meat plants.
26
MORIN, SOIZIC, ANNE-SOPHIE LAMBERT, JOAN ARTIGAS, MARINA COQUERY, and STÉPHANE PESCE. "Diatom immigration drives biofilm recovery after chronic copper exposure." Freshwater Biology 57, no. 8 (June 14, 2012): 1658–66. http://dx.doi.org/10.1111/j.1365-2427.2012.02827.x.
Full text
27
Boivin, Marie-Elène Y., Boris Massieux, Anton M. Breure, Gerdit D. Greve, Michiel Rutgers, and Wim Admiraal. "Functional recovery of biofilm bacterial communities after copper exposure." Environmental Pollution 140, no. 2 (March 2006): 239–46. http://dx.doi.org/10.1016/j.envpol.2005.07.014.
Full text
28
Lee, Sang Won, Joseph Carnicelli, Dariya Getya, Ivan Gitsov, K. Scott Phillips, and Dacheng Ren. "Biofilm Removal by Reversible Shape Recovery of the Substrate." ACS Applied Materials & Interfaces 13, no. 15 (April 6, 2021): 17174–82. http://dx.doi.org/10.1021/acsami.0c20697.
Full text
29
Bobadilla-Fazzini, Roberto A. "Mineralogical Dynamics of Primary Copper Sulfides Mediated by Acidophilic Biofilm Formation." Solid State Phenomena 262 (August 2017): 325–29. http://dx.doi.org/10.4028/www.scientific.net/ssp.262.325.
Full textAbstract:
Bioleaching of copper sulfides is catalyzed by iron-and sulfur-oxidizing acidophilic microorganisms attached to the mineral surface forming a biofilm. However, the link between copper sulfides bioleaching and biofilm formation is not yet fully understood. Understanding the factors that are limiting the bioleaching kinetics for different copper sulfide minerals through exhaustive mineralogical analysis of the mineral surface with concomitant biofilm formation during the leaching process will deliver new process conditions with enhanced kinetics and higher copper recovery. In this work we have developed and standardized a reproducible flow cell method able to mimic heap/dump bioleaching laminar flow conditions to study the mineralogical dynamics by advanced mineralogical analysis including QEMSCAN and SEM-EDS coupled to biofilm formation analysis. Based on this method, the bioleaching mineralogical dynamics of primary copper sulfides (enargite (Cu3AsS4), chalcopyrite (CuFeS2) and bornite (Cu5FeS4)) have been determined in the presence of biofilm formation. Supported by the observed mineralogical dynamics, different mechanisms of dissolution for bioleaching were observed as well as selective biofilm formation over the mineral surface, showing enhanced conditions for copper recovery.
30
Sukačová, Kateřina, Daniel Vícha, and Jiří Dušek. "Perspectives on Microalgal Biofilm Systems with Respect to Integration into Wastewater Treatment Technologies and Phosphorus Scarcity." Water 12, no. 8 (August 10, 2020): 2245. http://dx.doi.org/10.3390/w12082245.
Full textAbstract:
Phosphorus is one of the non-renewable natural resources. High concentration of phosphorus in surface water leads to undesirable eutrophication of the water ecosystem. It is therefore necessary to develop new technologies not only for capturing phosphorus from wastewater but also for phosphorus recovery. The aim of the study was to propose three different integration scenarios for a microalgal biofilm system for phosphorus removal in medium and small wastewater treatment plants, including a comparison of area requirements, a crucial factor in practical application of microalgal biofilm systems. The area requirements of a microalgal biofilm system range from 2.3 to 3.2 m2 per person equivalent. The total phosphorus uptake seems to be feasible for construction and integration of microalgal biofilm systems into small wastewater treatment plants. Application of a microalgal biofilm for phosphorus recovery can be considered one of the more promising technologies related to capturing CO2 and releasing of O2 into the atmosphere.
31
Paulsen, John E., Eirik Oppen, and Rune Bakke. "Biofilm morphology in porous media, a study with microscopic and image techniques." Water Science and Technology 36, no. 1 (July 1, 1997): 1–9. http://dx.doi.org/10.2166/wst.1997.0001.
Full textAbstract:
Biofilm activity, behaviour and our ability to control biofilms depends to a large extent on mass transfer phenomena in the biofilm, at the biofilm-liquid interface and in the bulk liquid. Biofilms respond to changing mass transfer conditions by adjusting morphology, thereby optimising the exchange of matter with their surroundings. Observing biofilm morphology and mass transfer in relevant fluid dynamic conditions can therefore yield essential information to understand and model biofilm behaviour. Lack of such knowledge, as the case is with regards to biofilm behaviour in various porous media, such as sandstone reservoirs, limits our ability to predict biofilm effects. A transparent porous media replica of a sandstone reservoir with cybernetic image processing has been designed to study biofilm related transport phenomena in porous media. The porous medium was inoculated with a mixed bacterial culture and fed a sterile nutrient solution in a once through flow mode. The biofilm was observed by microscopy with automated image analysis. This novel integrated software/hardware cybernetic design allows near real-time, essentially simultaneous, surveillance of several critical sites in the porous network and facilitates selective recording and compilation of observations as a function of the biological activity at each particular site. Biofilm biomass distribution in space and time (morphology and morphological changes) are thereby recorded at a representative selection of sites in the porous structure. Local in-pore flow velocity measurements were carried out by measuring the velocity of suspended particulate matter such as detached cells or clusters of cells. The influence of biofilm morphology on convective mass transport could thereby be observed and recorded. This effect, on a meso scale, was also monitored by sensitive, automated pressure drop measurements across the porous medium cell. Important observations so far include: • Bioweb; the biofilm morphology in porous media is very different from the “classical film”, as it appears more like a spider web where each strand varies in size and shape. • The biofilm maintains a large surface area and minimal biofilm depth, thereby minimising mass transfer resistance between the fluid and the biofilm phase, under the conditions tested. • The biofilm influences the convective flow through pores both locally within pores and effecting the flow distribution between pores. Pores with high initial permeability thereby become less permeable, diverting more flow to less permeable zones in the porous matrix. Large variations in this picture were observed, demonstrating the need for a sophisticated experimental apparatus with high sampling capacity to investigate such an intricate system. The observed biofilm behaviour in porous media has important theoretical and practical implications. Flow diversion and permeability effects are of immediate practical importance, improving the prospects for biological treatment of reservoirs. The information obtained in this study will be applied in mathematical simulations of ground water reservoirs, bioremediation and biological enhanced oil recovery.
32
Campanac, C., L. Pineau, A. Payard, G. Baziard-Mouysset, and C. Roques. "Interactions between Biocide Cationic Agents and Bacterial Biofilms." Antimicrobial Agents and Chemotherapy 46, no. 5 (May 2002): 1469–74. http://dx.doi.org/10.1128/aac.46.5.1469-1474.2002.
Full textAbstract:
ABSTRACT The resistance of bacterial biofilms to physical and chemical agents is attributed in the literature to various interconnected processes. The limitation of mass transfer alters the growth rate, and physiological changes in the bacteria in the film also appear. The present work describes an approach to determination of the mechanisms involved in the resistance of bacteria to quaternary ammonium compounds (benzalkonium chloride) according to the C-chain lengths of those compounds. For Pseudomonas aeruginosa CIP A 22, the level of resistance of the bacteria in the biofilm relative to that of planktonic bacteria increased with the C-chain length. For cells within the biofilm, the exopolysaccharide induced a characteristic increase in surface hydrophilicity. However, this hydrophilicity was eliminated by simple resuspension and washing. The sensitivity to quaternary ammonium compounds was restored to over 90%. Staphylococcus aureus CIP 53 154 had a very high level of resistance when it was in the biofilm form. A characteristic of bacteria from the biofilm was a reduction in the percent hydrophobicity, but the essential point is that this hydrophobicity was retained after the biofilm bacteria were resuspended and washed. The recovery of sensitivity was thus only partial. These results indicate that the factors involved in biofilm resistance to quaternary ammonium compounds vary according to the bacterial modifications induced by the formation of a biofilm. In the case of P. aeruginosa, we have underlined the involvement of the exopolysaccharide and particularly the three-dimensional structure (water channels). In the case of S. aureus, the role of the three-dimensional structure is limited and drastic physiological changes in the biofilm cells are more highly implicated in resistance.
33
Figueira, Leandro W., Beatriz H. D. Panariello, Cristiane Y. Koga-Ito, and Simone Duarte. "Low-Temperature Plasma as an Approach for Inhibiting a Multi-Species Cariogenic Biofilm." Applied Sciences 11, no. 2 (January 8, 2021): 570. http://dx.doi.org/10.3390/app11020570.
Full textAbstract:
This study aimed to determine how low-temperature plasma (LTP) treatment affects single- and multi-species biofilms formed by Streptococcus mutans, Streptococcus sanguinis, and Streptococcus gordonii formed on hydroxyapatite discs. LTP was produced by argon gas using the kINPen09™ (Leibniz Institute for Plasma Science and Technology, INP, Greifswald, Germany). Biofilms were treated at a 10 mm distance from the nozzle of the plasma device to the surface of the biofilm per 30 s, 60 s, and 120 s. A 0.89% saline solution and a 0.12% chlorhexidine solution were used as negative and positive controls, respectively. Argon flow at three exposure times (30 s, 60 s, and 120 s) was also used as control. Biofilm viability was analyzed by colony-forming units (CFU) recovery and confocal laser scanning microscopy. Multispecies biofilms presented a reduction in viability (log10 CFU/mL) for all plasma-treated samples when compared to both positive and negative controls (p < 0.0001). In single-species biofilms formed by either S. mutans or S. sanguinis, a significant reduction in all exposure times was observed when compared to both positive and negative controls (p < 0.0001). For single-species biofilms formed by S. gordonii, the results indicate total elimination of S. gordonii for all exposure times. Low exposure times of LTP affects single- and multi-species cariogenic biofilms, which indicates that the treatment is a promising source for the development of new protocols for the control of dental caries.
34
Figueira, Leandro W., Beatriz H. D. Panariello, Cristiane Y. Koga-Ito, and Simone Duarte. "Low-Temperature Plasma as an Approach for Inhibiting a Multi-Species Cariogenic Biofilm." Applied Sciences 11, no. 2 (January 8, 2021): 570. http://dx.doi.org/10.3390/app11020570.
Full textAbstract:
This study aimed to determine how low-temperature plasma (LTP) treatment affects single- and multi-species biofilms formed by Streptococcus mutans, Streptococcus sanguinis, and Streptococcus gordonii formed on hydroxyapatite discs. LTP was produced by argon gas using the kINPen09™ (Leibniz Institute for Plasma Science and Technology, INP, Greifswald, Germany). Biofilms were treated at a 10 mm distance from the nozzle of the plasma device to the surface of the biofilm per 30 s, 60 s, and 120 s. A 0.89% saline solution and a 0.12% chlorhexidine solution were used as negative and positive controls, respectively. Argon flow at three exposure times (30 s, 60 s, and 120 s) was also used as control. Biofilm viability was analyzed by colony-forming units (CFU) recovery and confocal laser scanning microscopy. Multispecies biofilms presented a reduction in viability (log10 CFU/mL) for all plasma-treated samples when compared to both positive and negative controls (p < 0.0001). In single-species biofilms formed by either S. mutans or S. sanguinis, a significant reduction in all exposure times was observed when compared to both positive and negative controls (p < 0.0001). For single-species biofilms formed by S. gordonii, the results indicate total elimination of S. gordonii for all exposure times. Low exposure times of LTP affects single- and multi-species cariogenic biofilms, which indicates that the treatment is a promising source for the development of new protocols for the control of dental caries.
35
Wong, Pan Yu, Maneesha P. Ginige, Anna H. Kaksonen, Ralf Cord-Ruwisch, David C. Sutton, and Ka Yu Cheng. "Simultaneous phosphorus uptake and denitrification by EBPR-r biofilm under aerobic conditions: effect of dissolved oxygen." Water Science and Technology 72, no. 7 (June 22, 2015): 1147–54. http://dx.doi.org/10.2166/wst.2015.325.
Full textAbstract:
A biofilm process, termed enhanced biological phosphorus removal and recovery (EBPR-r), was recently developed as a post-denitrification approach to facilitate phosphorus (P) recovery from wastewater. Although simultaneous P uptake and denitrification was achieved despite substantial intrusion of dissolved oxygen (DO >6 mg/L), to what extent DO affects the process was unclear. Hence, in this study a series of batch experiments was conducted to assess the activity of the biofilm under various DO concentrations. The biofilm was first allowed to store acetate (as internal storage) under anaerobic conditions, and was then subjected to various conditions for P uptake (DO: 0–8 mg/L; nitrate: 10 mg-N/L; phosphate: 8 mg-P/L). The results suggest that even at a saturating DO concentration (8 mg/L), the biofilm could take up P and denitrify efficiently (0.70 mmol e−/g total solids*h). However, such aerobic denitrification activity was reduced when the biofilm structure was physically disturbed, suggesting that this phenomenon was a consequence of the presence of oxygen gradient across the biofilm. We conclude that when a biofilm system is used, EBPR-r can be effectively operated as a post-denitrification process, even when oxygen intrusion occurs.
36
Oliveira, Viviane de Cássia, Marina Trevelin Souza, Edgar Dutra Zanotto, Evandro Watanabe, and Débora Coraça-Huber. "Biofilm Formation and Expression of Virulence Genes of Microorganisms Grown in Contact with a New Bioactive Glass." Pathogens 9, no. 11 (November 10, 2020): 927. http://dx.doi.org/10.3390/pathogens9110927.
Full textAbstract:
Bioactive glass F18 (BGF18), a glass containing SiO2–Na2O–K2O–MgO–CaO–P2O5, is highly effective as an osseointegration buster agent when applied as a coating in titanium implants. Biocompatibility tests using this biomaterial exhibited positive results; however, its antimicrobial activity is still under investigation. In this study we evaluated biofilm formation and expression of virulence-factor-related genes in Candida albicans, Staphylococcus epidermidis, and Pseudomonas aeruginosa grown on surfaces of titanium and titanium coated with BGF18. C. albicans, S. epidermidis, and P. aeruginosa biofilms were grown on specimens for 8, 24, and 48 h. After each interval, the pH was measured and the colony-forming units were counted for the biofilm recovery rates. In parallel, quantitative real-time polymerase chain reactions were carried out to verify the expression of virulence-factor-related genes. Our results showed that pH changes of the culture in contact with the bioactive glass were merely observed. Reduction in biofilm formation was not observed at any of the studied time. However, changes in the expression level of genes related to virulence factors were observed after 8 and 48 h of culture in BGF18. BGF18 coating did not have a clear inhibitory effect on biofilm growth but promoted the modulation of virulence factors.
37
Helmi, K., F. Menard-Szczebara, D. Lénès, P. Jacob, J. Jossent, C. Barbot, K. Delabre, and C. Arnal. "Adenovirus, MS2 and PhiX174 interactions with drinking water biofilms developed on PVC, cement and cast iron." Water Science and Technology 61, no. 12 (June 1, 2010): 3198–207. http://dx.doi.org/10.2166/wst.2010.821.
Full textAbstract:
Biofilms colonizing pipe surfaces of drinking water distribution systems could provide habitat and shelter for pathogenic viruses present in the water phase. This study aims (i) to develop a method to detect viral particles present in a drinking water biofilm and (ii) to study viral interactions with drinking water biofilms. A pilot scale system was used to develop drinking water biofilms on 3 materials (7 cm2 discs): PVC, cast iron and cement. Biofilms were inoculated with viral model including MS2, PhiX174 or adenovirus. Five techniques were tested to recover virus from biofilms. The most efficient uses beef extract and glycine at pH = 9. After sonication and centrifugation, the pH of the supernatant is neutralized prior to viral analysis. The calculated recovery rates varied from 29.3 to 74.6% depending on the virus (MS2 or PhiX174) and the material. Applying this protocol, the interactions of virus models (MS2 and adenovirus) with drinking water biofilms were compared. Our results show that adsorption of viruses to biofilms depends on their isoelectric points, the disc material and the hydrodynamic conditions. Applying hydrodynamic conditions similar to those existing in drinking water networks resulted in a viral adsorption corresponding to less than 1% of the initial viral load.
38
Agnello, M., L. Cen, N. C. Tran, W. Shi, J. S. McLean, and X. He. "Arginine Improves pH Homeostasis via Metabolism and Microbiome Modulation." Journal of Dental Research 96, no. 8 (May 9, 2017): 924–30. http://dx.doi.org/10.1177/0022034517707512.
Full textAbstract:
Dental caries can be described as a dysbiosis of the oral microbial community, in which acidogenic, aciduric, and acid-adapted bacterial species promote a pathogenic environment, leading to demineralization. Alkali generation by oral microbes, specifically via arginine catabolic pathways, is an essential factor in maintaining plaque pH homeostasis. There is evidence that the use of arginine in dentifrices helps protect against caries. The aim of the current study was to investigate the mechanistic and ecological effect of arginine treatment on the oral microbiome and its regulation of pH dynamics, using an in vitro multispecies oral biofilm model that was previously shown to be highly reflective of the in vivo oral microbiome. Pooled saliva from 6 healthy subjects was used to generate overnight biofilms, reflecting early stages of biofilm maturation. First, we investigated the uptake of arginine by the cells of the biofilm as well as the metabolites generated. We next explored the effect of arginine on pH dynamics by pretreating biofilms with 75 mM arginine, followed by the addition of sucrose (15 mM) after 0, 6, 20, or 48 h. pH was measured at each time point and biofilms were collected for 16S sequencing and targeted arginine quantification, and supernatants were prepared for metabolomic analysis. Treatment with only sucrose led to a sustained pH drop from 7 to 4.5, while biofilms treated with sucrose after 6, 20, or 48 h of preincubation with arginine exhibited a recovery to higher pH. Arginine was detected within the cells of the biofilms, indicating active uptake, and arginine catabolites citrulline, ornithine, and putrescine were detected in supernatants, indicating active metabolism. Sequencing analysis revealed a shift in the microbial community structure in arginine-treated biofilms as well as increased species diversity. Overall, we show that arginine improved pH homeostasis through a remodeling of the oral microbial community.
39
MG, Ruke, and Savai J. "Diabetic Foot Infection, Biofilm & New Management Strategy." Diabetes Research: Open Access 1, no. 1 (November 11, 2019): 7–22. http://dx.doi.org/10.36502/2019/droa.6152.
Full textAbstract:
The world is facing a major epidemic of diabetes mellitus (DM) & available reports suggest that all these patients are at risk of developing diabetic foot ulcer (DFU). Approximately 50 – 60% of all DFUs can be classified as neuropathic. Signs or symptoms of vascular compromise are observed in 40 to 50% of all patients with the vast majority having neuro-ischemic ulcers, and only a minority of patients has purely ischemic ulcers. Diabetic foot infections are usually polymicrobial in nature, involving both aerobes and anaerobes, which can decay any part of the body especially the distal part of the lower leg. However, one of the hidden barriers to wound healing is the presence of biofilm in chronic DFUs. Biofilms are difficult to identify & diagnose, recalcitrant to topical antibiotics & can reoccur even after sharp debridement. More than 90% of chronic wounds are complicated with biofilms. Hence, early identification and management of diabetic foot infections becomes imperative in order to prevent complications & amputation. Debridement is considered to be the gold standard treatment approach for managing DFU manifested with necrotic tissue. However, biofilm can reform even after sharp debridement and can delay healing & recovery. Also, antibiotics & few antiseptics have limited role in managing DFUs complicated with biofilm. Until recently, Cadexomer iodine, a new generation iodine formulation with microbead technology has taken a different profile in wound care. It can effectively manage biofilm along with exudate & possesses superior desloughing action. Additionally, appropriate ways of offloading, dressings & use of newer treatment strategies like negative pressure wound therapy (NPWT), hyperbaric oxygen therapy (HBOT) and / or use of growth factors can ensure faster healing & early wound closure. Although, commendable efforts in recent years have been taken in the diagnosis and treatment of DFU, it still remains a major public health concern.
40
Liu, Chong, Wenzong Liu, Jia Liu, Xu Zhou, Aijie Wang, and Jun Nan. "The effect of a short term biofilm-aeration treatment on energy recovery in microbial electrolysis cells." RSC Advances 5, no. 85 (2015): 69714–19. http://dx.doi.org/10.1039/c5ra11354g.
Full textAbstract:
Short-term air exposure to biofilm effectively inhibited methanogenesis in a MEC bioanode during 24 h batch operation. Compared to the anaerobic control, biofilm aeration increased H2 yield but presented little damage to the Coulombic efficiency.
41
Perfileva, Alla I., Olga A. Nozhkina, Tatjana V. Ganenko, Irina A. Graskova, Boris G. Sukhov, Alexander V. Artem’ev, Boris A. Trofimov, and Konstantin V. Krutovsky. "Selenium Nanocomposites in Natural Matrices as Potato Recovery Agent." International Journal of Molecular Sciences 22, no. 9 (April 27, 2021): 4576. http://dx.doi.org/10.3390/ijms22094576.
Full textAbstract:
The paper presents a study of the effect of chemically synthesized selenium nanocomposites (Se NCs) in natural polymer matrices arabinogalactan (AG) and starch (ST) on the viability of the potato ring rot pathogen Clavibacter sepedonicus (Cms), potato plants in vitro, and the soil bacterium Rhodococcus erythropolis. It was found that the studied Se NCs have an antibacterial effect against the phytopathogenic Cms, reducing its growth rate and ability to form biofilms. It was revealed that Se NC based on AG (Se/AG NC) stimulated the growth and development of potato plants in vitro as well as their root formation. At the same time, Se did not accumulate in potato tissues after the treatment of plants with Se NCs. The safety of the Se NCs was also confirmed by the absence of a negative effect on the growth and biofilm formation of the soil bacterium R. erythropolis. The obtained results indicate that Se NCs are promising environmentally safe agents for the protection and recovery of cultivated plants from phytopathogenic bacteria.
42
Sharma, Priya, and Srikanth Mutnuri. "Nutrient recovery and microbial diversity in human urine fed microbial fuel cell." Water Science and Technology 79, no. 4 (February 15, 2019): 718–30. http://dx.doi.org/10.2166/wst.2019.089.
Full textAbstract:
Abstract Presence of urine in municipal wastewater is a major problem faced by wastewater treatment plants. The adverse effects are noticeable as crystallization in equipment and pipelines due to high concentration of nitrogen and phosphorus. Therefore, improved technologies are required that can treat urine separately at the source of their origin and then discharge it in the main wastewater stream. In this study, the performance of the microbial fuel cell (MFC) was evaluated with mixed consortia and isolated pure cultures (Firmicutes and Proteobacter species) from biofilm for electricity generation and nutrient recovery. Microbes utilize less than 10% of total phosphorus for their growth, while 90% is recovered as struvite. The amount of struvite recovered was similar for pure and mixed culture (12 ± 5 g/L). The microbial characterization also shows that not all the biofilm-forming bacterial isolates are very much efficient in power generation and, hence, they can be further exploited to study their individual role in operating MFC. The different organic loading rates experiment shows that the performance of MFC in terms of power generation is the same for undiluted and five times diluted urine while the recovery of nutrients is better with undiluted urine, implying its direct use of urine in operating fuel cell.
43
Mavridou, A., J. Kamma, G. Mandilara, P. Delaportas, and F. Komioti. "Microbial risk assessment of dental unit water systems in general dental practice in Greece." Water Science and Technology 54, no. 3 (August 1, 2006): 269–73. http://dx.doi.org/10.2166/wst.2006.479.
Full textAbstract:
Water was sampled from source water, the 3-in-1 syringe and the air rotor water line of dental unit water systems (DUWS) in general dental practice in Attica, Greece. A section of the water line supplying the 3-in-1 syringe was cut for biofilm analysis. High total viable counts, Mycobacterium spp. and Pseudomonas aeruginosa were detected in the samples. Back siphonage was evidenced by the presence of blood and the recovery of oral anaerobes from the samples. Legionella pneumophila was recovered from 16.1% of biofilm samples. All tested disinfectants reduced the total viable counts of the DUWS to <100 CFU/mL.
44
Orfanos, Alexios G., and Ioannis D. Manariotis. "Algal biofilm ponds for polishing secondary effluent and resource recovery." Journal of Applied Phycology 31, no. 3 (January 10, 2019): 1765–72. http://dx.doi.org/10.1007/s10811-018-1731-8.
Full text
45
Gheorghe, Dan Cristian, Andrei Ilie, Adelina-Gabriela Niculescu, and Alexandru Mihai Grumezescu. "Preventing Biofilm Formation and Development on Ear, Nose and Throat Medical Devices." Biomedicines 9, no. 8 (August 16, 2021): 1025. http://dx.doi.org/10.3390/biomedicines9081025.
Full textAbstract:
Otorhinolaryngology is a vast domain that requires the aid of many resources for optimal performance. The medical devices utilized in this branch share common problems, such as the formation of biofilms. These structured communities of microbes encased in a 3D matrix can develop antimicrobial resistance (AMR), thus making it a problem with challenging solutions. Therefore, it is of concern the introduction in the medical practice involving biomaterials for ear, nose and throat (ENT) devices, such as implants for the trachea (stents), ear (cochlear implants), and voice recovery (voice prosthetics). The surface of these materials must be biocompatible and limit the development of biofilm while still promoting regeneration. In this respect, several surface modification techniques and functionalization procedures can be utilized to facilitate the success of the implants and ensure a long time of use. On this note, this review provides information on the intricate underlying mechanisms of biofilm formation, the large specter of implants and prosthetics that are susceptible to microbial colonization and subsequently related infections. Specifically, the discussion is particularized on biofilm development on ENT devices, ways to reduce it, and recent approaches that have emerged in this field.
46
Yang, Wanjing, Jie Shan, Yang Pan, Zhen Bi, Yong Huang, Hao Zhang, and Min Ni. "A new strategy for obtaining highly concentrated phosphorus recovery solution in biofilm phosphorus recovery process." Journal of Environmental Sciences 112 (February 2022): 366–75. http://dx.doi.org/10.1016/j.jes.2021.05.017.
Full text
47
McBain, Andrew J., Robert G. Bartolo, Carl E. Catrenich, Duane Charbonneau, Ruth G. Ledder, Alexander H. Rickard, Sharon A. Symmons, and Peter Gilbert. "Microbial Characterization of Biofilms in Domestic Drains and the Establishment of Stable Biofilm Microcosms." Applied and Environmental Microbiology 69, no. 1 (January 2003): 177–85. http://dx.doi.org/10.1128/aem.69.1.177-185.2003.
Full textAbstract:
ABSTRACT We have used heterotrophic plate counts, together with live-dead direct staining and denaturing gradient gel electrophoresis (DGGE), to characterize the eubacterial communities that had formed as biofilms within domestic sink drain outlets. Laboratory microcosms of these environments were established using excised biofilms from two separate drain biofilm samples to inoculate constant-depth film fermentors (CDFFs). Drain biofilms harbored 9.8 to 11.3 log10 cells of viable enteric species and pseudomonads/g, while CDFF-grown biofilms harbored 10.6 to 11.4 log10 cells/g. Since live-dead direct staining revealed various efficiencies of recovery by culture, samples were analyzed by DGGE, utilizing primers specific for the V2-V3 region of eubacterial 16S rDNA. These analyses showed that the major PCR amplicons from in situ material were represented in the microcosms and maintained there over extended periods. Sequencing of amplicons resolved by DGGE revealed that the biofilms were dominated by a small number of genera, which were also isolated by culture. One drain sample harbored the protozoan Colpoda maupasi, together with rhabtidid nematodes and bdelloid rotifers. The microcosm enables the maintenance of stable drain-type bacterial communities and represents a useful tool for the modeling of this ecosystem.
48
Parameswaran, Prathap, César I. Torres, Dae-Wook Kang, Bruce E. Rittmann, and Rosa Krajmalnik-Brown. "The role of homoacetogenic bacteria as efficient hydrogen scavengers in microbial electrochemical cells (MXCs)." Water Science and Technology 65, no. 1 (January 1, 2012): 1–6. http://dx.doi.org/10.2166/wst.2011.519.
Full textAbstract:
We evaluated the consumption of hydrogen gas at the anode of a microbial electrolysis cell (MEC) and characterized the significance of new interactions between anode respiring bacteria (ARB) and homo-acetogens. We demonstrated the significance of biofilm limitation for direct consumption of H2 over acetate by ARB, using the deep biofilm model. Selective inhibition of the major competing hydrogen sink at the biofilm anode, methanogenesis, resulted in significant increase in electron recovery as electric current (∼10–12 A/m2). The presence of acetate at high concentration in the anode compartment and detection of formate, a known intermediate of the acetyl-CoA pathway, provide evidence towards the role of homoacetogenic bacteria. We also assessed the activity of homoacetogens with reverse transcription quantitative PCR targeting formyltetrahydrofolate synthetase (FTHFS) transcripts, and observed a comparable decrease in the FTHFS transcript numbers with current density and acetate concentrations as we decreased the HRT below 4.5 h. The biofilm anode community was predominated by Deltaproteobacteria (70% of total readouts) along with a fraction of the homoacetogenic genus, Acetobacterium (4% of total readouts), established by pyrosequencing targeting the V6 region of the 16S rRNA. Homoacetogens seem to play a major role as syntrophic members of the biofilm anode community when electron recovery is high.
49
Falkinham, Joseph O., Cheryl D. Norton, and Mark W. LeChevallier. "Factors Influencing Numbers of Mycobacterium avium, Mycobacterium intracellulare, and Other Mycobacteria in Drinking Water Distribution Systems." Applied and Environmental Microbiology 67, no. 3 (March 1, 2001): 1225–31. http://dx.doi.org/10.1128/aem.67.3.1225-1231.2001.
Full textAbstract:
ABSTRACT Eight water distribution systems were sampled over an 18-month period (528 water and 55 biofilm samples) to measure the frequency of recovery and number of mycobacteria, particularly Mycobacterium avium and Mycobacterium intracellulare, in raw source waters before and after treatment and within the distribution system. The systems were chosen to assess the influence of source water, treatment, and assimilable organic carbon levels on mycobacterial numbers. Overall, mycobacterial recovery from the systems was low (15% of samples). Numbers of mycobacteria ranged from 10 to 700,000 CFU liter−1. The number of M. avium in raw waters was correlated with turbidity. Water treatment substantially reduced the number of mycobacteria in raw waters by 2 to 4 log units. Mycobacterial numbers were substantially higher in the distribution system samples (average, 25,000-fold) than in those collected immediately downstream from the treatment facilities, indicating that mycobacteria grow in the distribution system. The increase in mycobacterial numbers was correlated with assimilable organic carbon and biodegradable organic carbon levels (r 2 = 0.65, P = 0.03). Although M. intracellulare was seldom recovered from water samples, it was frequently recovered (six of eight systems) in high numbers from biofilms (average, 600 CFU/cm2). Evidently, the ecological niches of M. avium and M. intracellulare are distinct.
50
Rajbhandari, B. K., and A. P. Annachhatre. "Modeling response of nitrifying biofilm to inhibitory shock loads." Water Science and Technology 50, no. 6 (September 1, 2004): 53–60. http://dx.doi.org/10.2166/wst.2004.0359.
Full textAbstract:
To study the response of nitrifying biofilm to inhibitory shock loads, a lab-scale nitrifying biofilm reactor was operated in ambient conditions. Shock loads of various concentrations of inhibitory compound were applied to the biofilm. Aniline was used as an inhibitory compound. The experimental results were utilized to develop a model for predicting the variation of effluent nitrate concentration from the biofilm reactor for given shock loads of aniline concentration and exposure time both in exposure as well as in recovery phase. Close agreement between model and experimental observation of bulk aniline concentration and effluent nitrate concentration was obtained which indicates the usefulness of the model to estimate bulk aniline concentration and to predict the response of inhibitory shock loads on nitrifying biofilm.