Academic literature on the topic 'Penicillum species'

Thesis (MSc (Plant Pathology))--University of Stellenbosch, 2009.<br>ENGLISH ABSTRACT: Dry core rot (DCR) and wet core rot (WCR) are among some of the most important postharvest diseases of apples in South Africa. Mouldy core (MC) is also a symptom associated with the core region of apples, but it is not of economical importance since apple tissue surrounding the core region is not affected as is the case with DCR and WCR. The incidence of core rots in harvested fruits can be as high as 12%, but in general ranges from 3 to 8%. Infections and losses can also occur during fruit handling in pack houses and during storage. Additionally, yield losses also occur prior to harvest within orchards due to premature fruit drop of core rot affected fruits. The incidence of core rot diseases in apples differ among apple cultivars, with most Red Delicious varieties being susceptible to the development of core rots, whereas core rots have rarely been reported in other cultivars such as Granny Smith. The etiology and epidemiology of WCR and DCR are poorly understood. Although many fungal genera have been associated with the diseases, small-spored Alternaria species are mainly associated with DCR, whereas Penicillium species including P. roquefortii, P. expansum and P. funiculosum have mainly been associated with WCR. Dry core rot infections have long been known to occur pre-harvest, whereas WCR is primarily known as a post-harvest disease where infections take place during fruit handling in pack houses. Recently, Tarsonemus mites have also been indicated as being a potential role player in the etiology of core rot diseases. The mites have been hypothesised to carry pathogen spores into the core region of apples, and they may also possibly cause small wounds that facilitate pathogen entry. In South Africa, apple growers have recently reported WCR as being present prior to harvest, which has not been reported previously. Therefore, the first aim of the study was to investigate the incidence, as well as the causal agent/s of pre-harvest WCR. The incidence of WCR ranged from 0% to 1.7% in eleven orchards, and was in general lower than that of DCR (0.4% to 6%). Isolation studies from eight internal positions in WCR apples showed that Penicillium was the predominant fungal genus in most of the positions, including the lesion area. Morphological and molecular characterisation of Penicillium isolates from WCR showed that P. 2 ramulosum prov. nom. was the main species isolated from lesions, as well as other isolation positions. However, this species was also the main species isolated from DCR, MC and asymptomatic apples. Penicillium expansum was only isolated at low frequencies from WCR and DCR apples. Other Pencillium species that were occasionally isolated included P. glabrum, P. chloroloma, P. chermisinum and a putative new species with closest affinity to P. dendriticum (P. species aff. dendriticum) on a DNA nucleotide sequence basis. Pathogenicity and virulence studies using three different inoculation methods showed that P. expansum was the most virulent species, followed by P. species aff. dendriticum. The P. ramulosum prov. nom. isolates varied in their virulence, but were all considered to have low virulence. The role of Tarsonemus mites in the etiology and epidemiology of core rot diseases is poorly understood, and therefore the second aim of the study was to investigate some of these aspects. The specific aims of the study were to (1) investigate the ecology of Tarsonemus mites in Red Delicious and Granny Smith orchards during different apple developmental stages, (2) determine if there is a significant association of Tarsonemus mites with diseased (WCR and DCR) fruits and (3) determine if potential core rot pathogenic fungi are associated with the mites. Tarsonemus mites were found in all of the investigated apple developmental stages (buds, blossoms, 4cm diameter fruit, mature fruit and mummies), having the highest incidence in mummies and mature fruits from Red Delicious and Granny Smith orchards. In Red Delicious fruits the Tarsonemus mites were found within the core and/or calyx tube, whereas in Granny Smith fruits the mites were restricted to the calyx tube. In Red Delicious fruits there was a significant association between dry core rot as well as total core rot (wet- and dry-core rot) with the presence of mites in the core, as well as total mites (mites in core and calyx tubes). Fungal isolation studies from the Tarsonemus mites showed that they carried potential core rot fungal pathogens within the genera Penicillium and Alternaria. The Penicillium species isolated from the mites included two of the most virulent WCR species, P. expansum and P. species aff. dendriticum.<br>AFRIKAANSE OPSOMMING: Droë kernvrot and nat kernvrot is van die belangrikste na-oes siektes van appels in Suid- Afrika. Beskimmelde kern word ook met die kern van appels geassosieer, maar hierdie toestand is egter nie van ekonomiese belang nie, aangesien die weefsel rondom die kern nie geaffekteer word soos in die geval van nat- en droë kernvrot nie. Die voorkoms van kernvrot in vrugte na oes, kan vlakke van tot 12% bereik, maar oor die algemeen is die voorkoms tussen 3 en 8%. Infeksie en verliese kan ook voorkom gedurende die hantering en verpakking van vrugte in pakhuise en gedurende storing. Addisionele verliese in opbrengs kan ook voor-oes voorkom in boorde. Dit is te wyte aan voortydige vrugval van appels wat besmet is met kernvrot. Die voorkoms van kernvrot by appels verskil tussen kultivars. Meeste van die “Red Delicious” variëteite is vatbaar vir die ontwikkeling van kernvrot. Die toestand is egter skaars by ander kultivars soos Granny Smith. Die etiologie en epidemiologie van nat- en droë kernvrot word nie goed verstaan nie. ‘n Groot aantal swamgenera is al met kernvrot geassosieer. Klein-spoor Alternaria spesies word hoofsaaklik met droë kernvrot geassosieer en Penicillium spesies, insluitende P. roquefortii, P. expansum en P. funiculosum, word meestal met nat kernvrot geassosieer. Dit is lank reeds bekend dat droë kernvrot as voor-oes siekte kan voorkom, maar nat kernvrot is algemeen bekend as na-oes siekte waar infeksie tydens vrughantering en verpakking plaasvind. Daar is onlangs aangedui dat Tarsonemus myte potensiële rolspelers in die etiologie van kernvrot is. Hipoteties is die myte in staat om spore van die patogene in die kern van die appels in te dra, asook om klein wonde te veroorsaak wat infeksie deur patogene vergemaklik. In Suid-Afrika is nat kernvrot wat voor-oes in die boorde ontstaan onlangs deur boere aangemeld; hierdie toestand is nog nie op ‘n vorige geleentheid aangemeld nie. Die eerste doelwit van hierdie studie was dus om die voorkoms en veroorsakende organisme/s van voor-oes nat kernvrot te ondersoek. Die voorkoms van nat kernvrot was tussen 0 en 1.7% in elf boorde en was oor die algemeen laer as die voorkoms van droë kernvrot (0.4 tot 6%). Isolasiestudies uit agt interne posisies van nat kernvrot appels het getoon dat Penicillium die dominante swamgenus in die meeste posisies was, insluitend die letsels. Morfologiese en molekulêre karakterisering van 4 Penicillium isolate uit nat kernvrot letsels het aangedui dat P. ramulosum prov. nom. die spesie is wat die meeste geïsoleer is vanuit die letsels, asook ander isolasie posisies. Dié spesie was egter ook die mees algemene spesie wat uit nat- en droë kernvrot, asimptomatiese appels en appels wat slegs swamgroei in die kern gehad het, geïsoleer is. Penicillium expansum was ook in lae getalle uit nat- en droë kernvrotletsels geïsoleer. Ander Penicillium spesies wat ook soms geïsoleer is, sluit P. glabrum, P. chloroloma, P. chermisinum, asook ‘n moontlik nuwe spesie wat op DNA volgorde basis die naaste aan P. dendriticum (P. spesie aff. dendriticum) is. Studies wat patogenesiteit en virulensie van die isolate ondersoek het, is ook uitgevoer deur gebruik te maak van drie verskillende inokulasie metodes. Die studies het aangedui dat P. expansum die mees virulente spesie is, gevolg deur P. spesie aff. dendriticum. Die P. ramulosum prov. nom. isolate het variasie in virulensie getoon maar is oor die algemeen aanvaar om minder virulent te wees. Die rol van Tarsonemus myte in die etiologie en epidemiologie van kernvrot word nie goed verstaan nie en dus was die tweede doelwit van die studie om sommige van dié aspekte te ondersoek. Die spesifieke doelwitte was (1) om die ekologie van die Tarsonemus myte in “Red Delicious” en Granny Smith boorde tydens verskillende ontwikkelingstadiums van die appels te ondersoek, (2) om te bepaal of daar ‘n betekenisvolle assosiasie van Tarsonemus myte met siek (nat- en droë kernvrot) vrugte bestaan en (3) om te bepaal of potensiële kernvrot patogeniese swamme geassosieer is met die myte. Tarsonemus myte is gevind in al die ontwikkelingstadiums (knoppies, bloeisels, 4 sentimeter deursnee vrugte, volwasse vrugte en mummies) van appels wat ondersoek is. Die hoogste voorkoms van myte was in die mummies en volwasse vrugte van “Red Delicious”, asook Granny Smith kultivars gevind. In “Red Delicious” vrugte is myte in die kern en/of kaliksbuis gevind, maar in die Granny Smith vrugte was die myte tot die kaliksbuis beperk. In “Red Delicious” vrugte was daar ‘n betekenisvolle assosiasie tussen droë kernvrot, asook totale kernvrot (nat en droë kernvrot) met die teenwoordigheid van myte in die kern, asook totale myte (myte in die kern en kaliksbuis). Swam isolasiestudies vanaf die Tarsonemus myte het aangetoon dat potensiële kernvrot swampatogene in die genera Penicillium en Alternaria wel by die myte teenwoordig was. Die Penicillium spesies wat vanaf die myte geïsoleer is het twee van die mees virulente nat kernvrot spesies ingesluit, nl. P. expansum en P. spesie aff. dendriticum.

The overall aim of this research was to improve the understanding of the ecology and diversity of Trichoderma species within the soil and rhizosphere of onion (Allium cepa L.) and potato (Solanum tuberosum L.) under intensive management in New Zealand. The indigenous Trichoderma population was measured in a field trial at Pukekohe over a three year period under six different crop rotation treatments. The treatments included two continuous onion and potato rotations (intensive), two onion/potato mixed rotation (conventional), and two green manure rotations (sustainable). Results showed that Trichoderma populations were stable in both the rhizosphere and bulk soil (1.5 x 10² to 8.5 x 10³ CFU g⁻¹ ODS). The planting and incorporation of an oat (Avena sativa L.) green manure in the sustainable rotations positively increased Trichoderma colony forming unit (CFU) numbers in the rhizosphere soil from 3.4 x 10² to 2.5 x 10³ g⁻¹ ODS. A Trichoderma species identification method was developed based on colony morphology. Representative isolates were verified using restriction fragment length polymorphism (RFLP) and DNA sequencing. The method allowed for rapid and reliable identification of isolated Trichoderma species. Five species were identified in the Pukekohe soil: T. asperellum, T. atroviride, T. hamatum, T. harzianum and T. koningii. Results showed identical species diversity between the rhizosphere, rhizoplane and bulk soil. The species did not strongly compete between each other for the rhizosphere ecological niche and differences in species proportions seemed to be caused by environmental factors rather than the rotation treatments. The incorporation of oat green manure in pots did not significantly promote the indigenous Trichoderma population size and diversity in the rhizosphere of onion plants up to 4 months old. The identified species were the same as in the field trial. The incorporation of onion scale residues was shown to result in low Trichoderma and high Penicillium CFU numbers and a reduction in plant size. Additionally, the presence of high levels (6.0 x 10⁵ CFU g⁻¹ ODS) of Penicillium CFU was negatively correlated with the presence of Trichoderma CFU. The effect of oat incorporation on Trichoderma saprophytic growth was also investigated in a soil sandwich assay and revealed no significant differences. A series of experiments indicated that onion extract obtained from dry onion scale residues had no antifungal activity against either Trichoderma or Penicillium and instead tended to promote their hyphal growth and sporulation. It also showed that competition between Penicillium and Trichoderma isolates was limited despite the ability of Penicillium to produce a wide range of inhibitory substances. Four indigenous Trichoderma species (T. atroviride, T. hamatum, T. harzianum and T. koningii) were shown to be rhizosphere competent in a split tube experiment over a 6 week period. The results of this experiment revealed that, the Trichoderma species clearly displayed differences in their ability to colonise the rhizosphere of young onion seedlings. Species such as T. koningii had the greatest rhizosphere colonising ability regardless of soil depth while T. harzianum displayed the weakest ability. Results also indicated that when inoculated as a mixture the four species competed with one another to colonise the rhizosphere. Overall, this research indicated that the studied crop rotation treatments and the use of oat as a green manure did not strongly promote indigenous Trichoderma populations. Species diversity was constant throughout the research with T. hamatum and T. koningii being the most frequently isolated species.

Submitted by Pedro Barros (pedro.silvabarros@ufpe.br) on 2018-08-22T19:56:23Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Vanilla Mergulhão Alves da Silva.pdf: 1395805 bytes, checksum: a5cf6b0279abcd07902c3eaa91c7655c (MD5)<br>Approved for entry into archive by Alice Araujo (alice.caraujo@ufpe.br) on 2018-08-29T21:37:39Z (GMT) No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Vanilla Mergulhão Alves da Silva.pdf: 1395805 bytes, checksum: a5cf6b0279abcd07902c3eaa91c7655c (MD5)<br>Made available in DSpace on 2018-08-29T21:37:39Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Vanilla Mergulhão Alves da Silva.pdf: 1395805 bytes, checksum: a5cf6b0279abcd07902c3eaa91c7655c (MD5) Previous issue date: 2016-02-24<br>CAPES<br>Tanase é uma enzima extracelular induzível produzida por fungos filamentosos, leveduras e bactérias através de Fermentação em Estado Sólido (FES) ou Submersa (FS). Taninos são compostos fenólicos presentes nas plantas, sendo assim, as folhas podem ser ótimos indicadores para a produção da tanase. Espécies de Aspergillus e Penicillium se destacam na produção da FES devido a capacidade de suportar diferentes condições físico-quimica. Os objetivos deste trabalho foram avaliar a produção de tanase por isolados de Aspergillus e Penicillium, através da FES, utilizando folhas de castanhola (Terminalia catappa L.) como substrato, selecionar o melhor produtor de tanase, otimizar a produção, purificar e aplicar na clarificação dos sucos de mangaba (Hancornia speciosa Gomes) e tamarindo (Tamarindus indica L.). As melhores condições foram determinadas utilizando como ferramenta o Planejamento Placket-Burman (PB) e Metodologia de Superfície de Resposta (MSR). Todas as culturas testadas produziram atividade entre 238,93 e 2088,19 U/gbs. Aspergillus carneus URM 5577 se destacou como o melhor produtor. Os melhores parâmetros para a produção de tanase foram: 70 horas de cultivo, pH 6,0, ácido tânico na concentração de 7% à 28°C, como variável resposta a atividade de 5449,31 U/gbs. A melhor condição para a pré-purificação foi a massa molecular do PEG 8000 (g/mol), concentração de PEG de 15% (m/m), citrato de 25% (m/m) e pH 8,0. Em sua aplicação, com o extrato bruto, o suco de mangaba reduziu o teor de tanino em 49,66% após 90 minutos, e tamarindo em 51,82% aos 120 minutos de incubação à 37 °C. As folhas da castanhola se mostrou como um excelente potencial para a produção da enzima, diminuindo assim os custos da produção e enaltecendo o valor do substrato.<br>Tannase is an inducible extracellular enzyme produced by filamentous fungi, yeasts and bacteria by Solid-State Fermentation (SSF) or submerged (SmF). Tannins are phenolic compounds present in plants, therefore, the sheets can be good indicators for the production of tannase. Species of Aspergillus and Penicillium are highlighted in the production of SSF because of the ability to support different physical and chemical conditions. The objectives of this study were to evaluate the production of tannase by isolates of Aspergillus and Penicillium, by SSF, using sheets of castanets (Terminalia catappa L.) as a substrate, selecting the best tannase producer, optimize production, purify and apply the clarification mangaba of juices (Hancornia speciosa Gomes) and tamarind (Tamarindus indica L.). The best conditions were determined using as a tool the Placket-Burman Planning (PB) and Response Surface Methodology (RSM). All tested crops produced activity between 238.93 and 2088.19 U/gds. Aspergillus carneus URM 5577 stood out as the best producer. The best parameters for producing tannase were 70 hours of cultivation, pH 6.0, tannic acid at a concentration of 7% at 28°C as the response variable 5449.31 activity U/gds. The best condition for the pre-purification was the molecular weight of PEG 8000 (g/mol), concentration of PEG 15% (w/w), 25% citrate (w/w) and pH 8.0. In its application, with the crude extract, the mangaba juice reduced the tannin content of 49.66% after 90 minutes and tamarind 51.82% to 120 minutes of incubation at 37°C. The leaves of the castanet was shown as an excellent potential for the production of the enzyme, thereby lowering the cost of production and exalting the value of the substrate.

Penicillium species have been studied for over 200 years and the genus was first described by Link in 1809. Initially, morphological identification methods were used however, much diversity within the genus resulted in researchers seeking alternative techniques and approaches to improve accuracy. These methods involved biochemical analysis of secondary metabolites in conjunction with morphological examination. With the emergence of more accurate and rapid molecular identification tools, scientists embraced modem technology to address diversity challenges. In order to provide a more holistic approach towards the taxonomy of complex genera, morphological analysis remains an essential component in Penicillium identification. Penicillium species are omnipresent, dominant and problematic in postharvest environments. They are known to cause major losses in export markets due to fruit decay. The aim of this study was to identify species within the South African litchi export chain and develop a rapid method for Penicillium identification. This study used morphological as well as molecular identification methods in order to develop PCR-RFLP restriction maps for a number of dominant Penicillium species. Seventeen species of Penicillium were identified using conventional morphological methodology and DNA sequencing, both of which are laborious and time-consuming. Polymerase Chain Reaction-Restriction Fragment Length Polymorphism provided reliability and repeatability as well as being a cost-effective and rapid identification alternative. A combined phylogenetic study indicated that the taxonomic position of several species may need to be reconsidered. Fourteen species were differentiated from one another through digestion of the â-tubulin gene region with five restriction enzymes. Banding patterns correlated well with phylogenetic and biochemical data of related studies, indicating that this method holds promise as a rapid identification procedure for Penicillium species.<br>Dissertation (MSc)--University of Pretoria, 2011.<br>Microbiology and Plant Pathology<br>unrestricted

Nontypeable Haemophilus influenzae (NTHi) is an opportunistic human pathogen responsible for diseases such as exacerbations of chronic bronchitis, community acquired pneumonia, otitis media and occasionally conjunctivitis. H. haemolyticus is closely related to NTHi and shares the same respiratory niche as a commensal, but is not an opportunistic respiratory pathogen. Both NTHi and H. haemolyticus can acquire resistance to β-lactam antibiotics via mutations to the ftsI gene and associated amino acid substitutions in penicillin binding protein 3 (PBP3) and the prevalence of such resistant strains is increasing worldwide. The factors associated with pathogenicity of NTHi are complicated, but can include mucociliary interactions, attachment to respiratory mucosa, evasion of mucosal immunity, and invasion of respiratory epithelial cells. There is significant in vivo and in vitro evidence that NTHi can invade and persist within host epithelial cells leading to the hypothesis that this allows the organism to avoid the normal immune response and establish a persistent reservoir for infection. Despite increased understanding of some mechanisms involved with invasion, the relationship between intracellular NTHi and pathogenesis is still unclear and many studies have shown enormous strain-to-strain variation in the in vitro invasive ability of clinical isolates. One of the limitations in understanding the relationship between intracellular NTHi and pathogenesis is the lack of a standardised model for studying invasion, as a very large range of both respiratory and non-respiratory, and primary and immortal cell lines have been used, often without explanation or justification. It is unclear whether an isolate that shows in vitro invasion in one cell type will be similarly invasive in another cell type, and this makes comparisons between studies very difficult. The aims of this thesis were to investigate the effect of respiratory cell types and presence of altered PBP3 on invasion rate of NTHi and Haemophilus haemolyticus. To investigate our aims, we established a large collection of NTHi and H. haemolyticus isolates where the identity had been confirmed previously using a validated PCR algorithm as either NTHi (being positive for hpd#3 or fucK and negative for sodC) or H. haemolyticus (positive for sodC and negative for both hpd#3 and fucK. In this working collection, NTHi isolates were collected from four different sites and clinical conditions such as otitis media, conjunctivitis, lower respiratory tract infection and normal oropharyngeal flora, whereas H. haemolyticus isolates were recovered from the oropharynx of healthy individuals. These isolates were tested for invasion using the gentamicin survival assay with immortalised BEAS-2B (Sigma-Aldrich); isolated from normal human bronchial epithelium of non-cancerous individuals NHBE (Lonza); isolated from epithelial lining of airways above bifurcation of the lungs A549 (Public Health England); epithelial lung carcinoma cells derived from 58 year old Caucasian male and NCI-H292 (ATCC); muco-epidermoid pulmonary carcinoma cells derived from 32 year old female epithelia cell lines. Cell lines were grown and maintained in LHC8 (Gibco), BEGM (Lonza), DMEM growth medium (Sigma-Aldrich) supplemented with 2Mm Glutamine and 10% Foetal Bovine Serum (FBS), and RPMI 1640 medium (Sigma-Aldrich) supplemented with 10% FBS respectively at 370C in 5% CO\(_2\). Chapter 3 is a detailed study of the invasive ability of NTHi, possessing normal or PBP3, using four different and widely used respiratory cell types: BEAS-2B, NHBE, A549, and NCI-H292. The focus of this study was to evaluate if there is any difference in invasive ability of NTHi isolates individually, collectively and between isolates with normal and altered PBP3 across each cell type. The results showed that NTHi invasion of respiratory epithelial cells in vitro is both strain dependant and influenced significantly by the type of cell lines used and also confirmed the previous suggestions, provided by Okabe et al. (2010) and Atkins et al. (2014), that isolates with altered PBP3 possess more invasive ability compared to isolates with normal PBP3. Furthermore, the association between altered PBP3 and increased invasion was conserved across each cell line. H.haemolyticus is considered to be a non-pathogenic commensal of the respiratory tract butlittle information is available on its ability to invade epithelial cells in vitro. If in vitro invasion is an indicator of ability for in vivo invasion and is important in the pathogenesis of NTHi infection, then H. haemolyticus would be expected to be comparatively non-invasive. As a result, Chapter 4 examined the invasive ability of H. haemolyticus to the BEAS-2B cell line. The invasion rate of 20 H. haemolyticus isolates were tested with BEAS-2B cell line and then 5/20 isolates were selected to test their invasion rate with other respiratory cell types used previously in this study. The results confirmed that non-invasiveness of H. haemolyticus isolates is consistent with their inability to cause respiratory infections. In conclusion, this thesis has demonstrated the significant variability of invasion results across different epithelial cell lines, highlighting the importance of the choice of cell type in invasion assays as a confounding factor, as the ability of NTHi to invade respiratory epithelial cells in vitro is both strain dependant and influenced significantly by the respiratory cell types. Furthermore, we have shown that the association between altered PBP3 and increased invasion is conserved across all the respiratory epithelial cell types used in this study. Finally, this thesis also revealed the inability of H. haemolyticus isolates to invade respiratory epithelial cell types in vitro, and suggests that this is consistent with their inability to cause opportunistic respiratory tract infections.