Academic literature on the topic 'Aerobacter cloacae'

Trying to work out a fast, simple and convenient assessment method for the wastewater of bio-pharmaceutical industry, microcosm, dose-effective relation analysis and fitting function analysis were performed, according to the better reactivity of microbial in pharmaceutical environmental risk assessment, to select representative microbial indicator on the basis of coefficient of fitting function. Among 4 candidates, a significant negative co-relation (r=-0.981, P=0.003) among the mass growths (OD600) of Aerobacter cloacae and the concentrations of artificial composed water was seen with a coefficient (R2) of 0.9626. So the aerobacter cloacae was selected as an indicator, and its equation of fitting function was: y=-0.0634x+0.1623; Risk levels were set according to the fitting function: OD600≥0.1623 no risk，0.0812＜OD600＜0.1623 low risk，0.0000＜OD600≤0.0812 medium risk，OD600≤0.0000 high risk.

Utilization of glycerol biodiesel waste via biological process 1: Selection of microbesThe availability of glycerol, a byproduct of biodiesel production, is increasing along with the growth of biodiesel industries. While glycerol is used in various industries such as food, pharmaceutical, and cosmetics, the purification of crude glycerol from biodiesel waste can be very costly and inefficient. Literature study indicated that some microorganism could utilize glycerol as their substrate. This forms the basis for applying microbial conversion of glycerol into valuable products. This paper presents our study in exploring the microbial potentials in utilizing pure glycerol as substrate, which is a part of a larger study in converting crude glycerol from biodiesel waste through microbial processes. In this study the potentials of Aerobacter aerogenes ITBCC B88, Klebsiella pneumoniae ITBCC113, and Enterobacter cloacae NRLL B411, NRLL B23264, and NRLL B23289 in utlizing glycerol were explored. The study covered the aerobic growth tests of each strain using glycerol as C-source in substrate, by varying glycerol concentration and C/N ratio in the media. The results indicated that all the tested strains could grow well in glycerol and would assimilate glycerol better in low C/N ratio. However, the increase in microbial glycerol consumption did not increase the biomass yield, which might indicate the production of metabolic products.Keywords: glycerol, biodiesel, Aerobacter aerogenes, Klebsiella pneumoniae, Enterobacter cloacae AbstrakKetersediaan gliserol, produk samping industri biodiesel, semakin meningkat seiring pertumbuhan industri biodiesel. Meskipun gliserol murni banyak digunakan dalam industri makanan, farmasi, kosmetik, dan industri-industri lainnya, pemurnian limbah gliserol menjadi gliserol murni sangat mahal dan tidak efektif. Studi literatur menunjukkan bahwa beberapa jenis mikroba dapat menggunakan gliserol sebagai substratnya. Hal ini menjadi dasar untuk menerapkan proses pengolahan gliserol menjadi produk bermanfaat melalui proses mikrobiologik. Makalah ini menyajikan hasil penelitian eksplorasi potensi mikroba dalam mengkonversi gliserol murni dalam substrat, yang merupakan tahap awal dari rangkaian penelitian pemanfaatan limbah gliserol melalui proses mikrobiologik. Dalam penelitian ini diteliliti kemampuan mikroba Aerobacter aerogenes ITBCC B88, Klebsiella pneumoniae ITBCC113, dan Enterobacter cloacae NRLL B411, NRLL B23264, dan NRLL B23289 dalam memanfaatkan gliserol. Penelitian yang dilakukan meliputi uji pertumbuhan pada substrat gliserol murni dan kondisi aerobik, dengan memvariasikan konsentrasi gliserol dan nisbah C/N dalam media. Hasil penelitian menunjukkan semua mikroba uji dapat tumbuh dengan baik pada substrat gliserol dan mengasimilasi gliserol lebih baik pada nisbah C/N media yang lebih rendah. Namun demikian peningkatan konsumsi gliserol selama proses kultivasi tidak diikuti oleh peningkatan perolehan biomassa, yang mengindikasikan terjadinya pembentukan produk-produk metabolit oleh mikroba.Kata kunci: gliserol, biodiesel, Aerobacter aerogenes, Klebsiella pneumoniae, Enterobacter cloacae

ABSTRACT Enterobacter cloacae is not a primary human pathogen but has been considered to be an important cause of nosocomial infections. Even so, there are almost no reports on its ability to produce recognized virulence-associated properties. In this study, we show that most of the E. cloacae strains examined were resistant to serum bactericidal activity and were able to produce aerobactin and mannose-sensitive hemagglutinin, and all of them could adhere to and invade HEp-2 cells. Since E. cloacae is part of the normal intestinal floras of many individuals, we believe that infectious disease due to endogenous E. cloacae might be a result of both host predisposing factors and the bacterial virulence determinants that we have detected in this survey.

ABSTRACT Pseudomonas spp. have the capacity to utilize siderophores produced by diverse species of bacteria and fungi, and the present study was initiated to determine if siderophores produced by rhizosphere microorganisms enhance the levels of iron available to a strain of Pseudomonas putida in this natural habitat. We used a previously described transcriptional fusion (pvd-inaZ) between an iron-regulated promoter (pvd) and the ice nucleation reporter gene (inaZ) to detect alterations in iron availability toP. putida. Ice nucleation activity (INA) expressed from thepvd-inaZ fusion by P. putida N1R or N1R Pvd−, a derivative deficient in the production of a pyoverdine siderophore, was inversely related to the concentration of ferric citrate in a culture medium. In culture, INA expressed by N1R Pvd− (pvd-inaZ) was reduced in the presence of the ferric complex of pseudobactin-358, a pyoverdine siderophore produced by P. putida WCS358 that can be utilized as a source of iron by N1R Pvd−. In the rhizosphere of cucumbers grown in sterilized soil, N1R Pvd− (pvd-inaZ) expressed INA, indicating that iron availability was sufficiently low in that habitat to allow transcription of the iron-regulated pvd promoter. Coinoculation with WCS358 or N1R significantly decreased INA expressed by N1R Pvd− (pvd-inaZ) in the rhizosphere, whereas coinoculation with a pyoverdine-deficient mutant of WCS358 did not reduce INA expressed by N1R Pvd−(pvd-inaZ). These results indicate that iron availability to N1R Pvd−(pvd-inaZ) in the rhizosphere was enhanced by the presence of another strain of P. putida that produces a pyoverdine that N1R Pvd−(pvd-inaZ) was able to utilize as a source of iron. In culture, strain N1R Pvd− also utilized ferric complexes of the siderophores enterobactin and aerobactin as sources of iron. In the rhizosphere of cucumbers grown in sterilized soil, INA expressed by N1R Pvd− (pvd-inaZ) was reduced in the presence of strains of Enterobacter cloacae that produced enterobactin, aerobactin, or both siderophores, but INA expressed by N1R Pvd−(pvd-inaZ) was not altered in the presence of a mutant of E. cloacae deficient in both enterobactin and aerobactin production. Therefore, the iron status of P. putida was altered by siderophores produced by an unrelated bacterium coinhabiting the rhizosphere. Finally, we demonstrated that INA expressed by N1R containing pvd-inaZ in the rhizosphere differed between plants grown in sterilized versus nonsterilized field soil. The results of this study demonstrate that (i) P. putida expresses genes for pyoverdine production and uptake in the rhizosphere, but the level of gene expression is influenced by other bacteria that coexist with P. putida in this habitat, and (ii) diverse groups of microorganisms can alter the availability of chemical resources in microbial habitats on root surfaces.