Co-immobilized microbial biosensor for BOD estimation based on sol-gel derived composite material

A novel type of biochemical oxygen demand (BOD) biosensor was developed for water monitor, based on co-immobilizing of Trichosporon cutaneum and Bacillus subtilis in the sol-gel derived composite material which is composed of silica and the grafting copolymer of poly (vinyl alcohol) and 4-vinylpyridine (PVA-g-P(4-VP)). Factors that influence the performance of the resulting biosensor were examined. The biodegradable substrate spectrum could be expanded by the co-immobilized microorganisms. The biosensor prepared also exhibited good reproducibility and long-term stability. Good agreement was obtained between the results of the sensor BOD measurement and those obtained from conventional BOD5 method for water samples.

皮状丝孢酵母发酵大米草水解液生产微生物油脂

大米草是一种外来引种植物，本来引进的目的是为了保滩护岸、促淤造陆。然而大米草过度繁殖，侵袭海洋沿岸滩涂，所以综合开发大米草有着重要的经济意义和生态意义。本实验研究着力于将大米草水解液通过皮状丝孢酵母发酵而制取生物油脂。并且随着近年来石油价格的攀升和对于汽车尾气对环境造成的日趋严重的污染，生物柴油的开发受到高度重视。微生物油脂则是生物柴油生产的很好的原料，因为它无需占用耕地，而能够把农业加工剩余物或是其它的含纤维素的生物质转化为油脂。 本实验采用产油酵母菌皮状丝孢酵母（Trichosporon cutaneum）直接发酵经过简单脱毒处理的大米草水解液生产微生物油脂。在122℃，固—液比为10%（w/v），分别用1%、2%、4%和6%稀硫酸水解大米草，结果表明在6%的酸浓度下水解40 min后还原糖含量最高，达到22.8 g/L。而同时以1%稀硫酸在140℃下水解大米草，2.8h后，水解液中葡萄糖产量达到最高14.2g/L。确定了摇瓶发酵最适工艺条件：摇床转速200 rpm，接种量10%（v/v），装液量为200 mL (1000-mL三角瓶)。在此基础上，确定了水解液最适浓缩倍数和pH值，水解液浓缩倍数为4.0时产油量高达6.0 g/L，产油率为46.3%。本文为高效利用大米草提供了新的途径。 关键词:皮状丝孢酵母,大米草,水解,发酵,微生物油脂

Development of a novel PCR assay for the identification of the black yeast, Exophiala (Wangiella) dermatitidis from adult patients with cystic fibrosis (CF)

Cystic fibrosis (CF) patients may suffer increased morbidity and mortality through colonisation, allergy and invasive infection from fungi. The black yeast, Exophiala dermatitidis (synonym Wangiella dermatitidis) has been found with increasing frequency in sputum specimens of CF patients, with reported isolation rates ranging from 1.1 to 15.7%. At present, no diagnostic PCR exists to aid with the clinical laboratory detection and identification of this organism. A novel species-specific PCR-based assay was developed for the detection of E. dermatitidis, based on employment of rDNA operons and interspacer (ITS) regions between these rDNA operons. Two novel primers, (designated ExdF & ExdR) were designed in silico with the aid of computer-aided alignment software and with the alignment of multiple species of Exophiala, as well as with other commonly described yeasts and filamentous fungi within CF sputum, including Candida. Aspergillus and Scedosporium. An amplicon of approximately 455 by was generated, spanning the partial ITS I region - the complete 5.8S rDNA region - partial ITS2 region, employing ExdF (forward primer [16-mer], 5'-CCG CCT ATT CAG GTC C-3' and ExdR (reverse primer [16-mer], 5'-TCT CTC CCA CTC CCG C-3', was employed and optimised on extracted genomic DNA from a well characterised culture of E. dermatitidis, as well as with high quality genomic DNA template from a further 16 unrelated fungi, including Candida albicans, C. dubliniensis, C. parapsilosis, C. glabrata, Scedosporium apiospermum, Penicillium sp., Aspergillus fumigatus, Aspergillus versicolor, Pichia guilliermondii, Rhodotorula sp., Trichosporon sp., Aureobasidium pullulans, Fusarium sp., Mucor hiemalis, Bionectria ochroleuca, Gibberella pulicaris. Results demonstrated that only DNA from E. dermatitidis gave an amplification product of the expected sire, whilst none of the other fungi were amplifiable. Subsequent employment of this primer pair detected this yeast from mycological cultures from 2/50 (4%) adult CF patients. These two patients were the only patients who were previously shown to have a cultural history of E. dermatitidis from their sputum. E. dermatitidis is a slow-growing fungus, which usually takes up to two weeks to culture in the microbiology laboratory and therefore is slow to detect conventionally, with the risk of bacterial overgrowth from common co-habiting pan- and multiresistant bacterial pathogens from sputum. namely Pseudomonas aeruginosa and Burkholderia cepacia complex organisms, hence this species-specific PCR assay may help detect this organism from CF sputum more specifically and rapidly. Overall, employment of this novel assay nay help in the understanding of the occurrence. aetiology and epidemiology of E. dermatitidis, as an emerging fungal agent in patients with CF. (C) 2008 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Characterization of the Phenol Monooxygenase Gene from Chromobacterium violaceum: Potential Use for Phenol Biodegradation

In this work, the biodegradation mechanism of phenol and sub products (such as catechol and hydroquinone) in Chromobacterium violaceum was investigated by cloning and molecular characterization of a phenol monooxygenase gene in Escherichia coli. This gene (Cvmp) is very similar (74 and 59% of similarity and identity, respectively) to the ortholog from Ralstonia eutropha, bacteria capable of utilizing phenol as the sole carbon source. The phenol biodegradation ability of E. coli recombinant strains was tested by cell-growth in a minimal medium containing phenol as the sole source of carbon and release of intermediary metabolites (catechol and hydroquinone). Interestingly, during the growth of these strains on phenol, catechol, and hydroquinone accumulated transiently in the medium. These metabolites were further analyzed by HPLC. These results indicated that phenol can be initially orto or para hydroxylated to produce cathecol or hydroquinone, respectively, followed by meta-cleavage of aromatic rings. To verify this information, the metabolites obtained from HPLC were submitted to LC/MS to confirm their chemical structure, thereby indicating that the recombinant strains utilize two different routes simultaneously, leading to different ring-fission substrates for the metabolism of phenol. (C) KSBB

Cryptococcus haglerorum, sp nov., an anamorphic basidiomycetous yeast isolated from nests of the leaf-cutting ant Atta sexdens

A yeast strain (CBS 8902) was isolated from the nest of a leaf-cutting ant and was shown to be related to Cryptococcus humicola. Sequencing of the D1/D2 region of the 26S ribosomal DNA and physiological characterization revealed a separate taxonomic position. A novel species named Cryptococcus haglerorum is proposed to accommodate strain CBS 8902 that assimilates n-hexadecane and several benzene compounds. Physiological characteristics distinguishing the novel species from some other members of the C. humicola complex are presented. The phylogenetic relationship of these strains to species of the genus Trichosporon Behrend is discussed.

Monitoramento de fungos anemófilos e de leveduras em unidade hospitalar

OBJETIVO: Monitorar e caracterizar fungos anemófilos e leveduras de fontes bióticas e abióticas de uma unidade hospitalar. MÉTODOS: As coletas foram realizadas mensalmente e em dois períodos, do centro cirúrgico e unidades de terapia intensiva adulto e neonatal em hospital de Araraquara, Estado de São Paulo. Para coleta de fungos anemófilos foi utilizado amostrador tipo Andersen de simples estágio. A pesquisa de leveduras foi feita das mãos e de orofaringe de profissionais de saúde, bem como de superfícies de leitos e de maçanetas das áreas críticas. RESULTADOS: Foram recuperados do centro cirúrgico 32 gêneros de fungos anemófilos e 31 das unidades de terapia intensiva. Os gêneros mais freqüentemente isolados foram Cladophialophora spp., Fusarium spp., Penicillium spp., Chrysosporium spp. e Aspergillus spp. Durante o período de estudo, houve reforma e implantação de uma unidade dentro do hospital, que coincidiu com o aumento na contagem de colônias de Cladophialophora spp., Aspergillus spp. e Fusarium spp. Leveduras foram encontradas em 39,4% dos profissionais de saúde (16,7% das amostras dos espaços interdigitais, 12,1% do leito subungueal e 10,6% da orofaringe) e, em 44% das amostras do mobiliário, com predomínio do gênero Candida (C. albicans, C. guilliermondii, C. parapsilosis e C. lusitaniae) seguido por Trichosporon spp. CONCLUSÕES: Observou-se número relativamente elevado de fungos anemófilos (potencialmente patogênicos) em áreas especiais e níveis expressivos de leveduras em fontes bióticas e abióticas. O monitoramento microbiológico ambiental deve ser realizado, principalmente em salas especiais com pacientes imunocomprometidos, sujeitos à exposição de patógenos do meio ambiente, assim como, advindos de profissionais de saúde.

Species diversity of yeast in oral colonization of insulin-treated diabetes mellitus patients

The aim of this study was to investigate oral yeast colonization, antifungal susceptibility and strain diversity in insulin-dependent diabetes mellitus patients (175), as well as to evaluate the influence of dental prostheses. Oral rinse samples were cultured on selective media, in order to isolate, count and identify the yeasts recovered. More than half of the diabetic subjects (53%) carried significant amounts of Candida cells in the buccal cavity and these organisms were recovered at higher densities in diabetics wearing dentures. A total of 93 yeast strains were isolated from these patients, including: Candida spp. (n = 89); Pichia (n = 02); Trichosporon (n = 1), and Geotrichum (n = 1). C. albicans represented 56% of these strains, non-albicans Candida 39.8%, and other genera of yeast 4.3%. C. albicans was prevalent, followed by C. parapsilosis, C. tropicalis, C. glabrata, C. krusei, C. rugosa and C. guilliermondii. Agar disk-diffusion tests of the susceptibility of non-albicans Candida and other genera of yeast to fluconazole showed resistance in 21.9%, mainly in C. rugosa (100%), C. glabrata (57%) and C. krusei (50%). Local oral factors, such as the presence of dentures, in association with diabetes, seemed to have the effect of increasing the amount and variety of Candida species in the oral cavities, mainly those with lower drug susceptibilities.

Microbiological evaluation of different strategies for management of snakes in captivity

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Oral colonization by yeasts in hiv-positive patients in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Yeasts associated with nests of the leaf-cutting ant Atta sexdens rubropilosa Forel, 1908

A total of 137 yeasts associated with the leaf-cutting ant Atta sexdens rubropilosa Forel, 1908 were characterized, being selected 93 for analysis. Twenty four species belonging to seven genera(Candida, Cryptococcus, Rhodotorula, Sporobolomyces, Tremella, Trichosporon, Pichia) were isolated from the different analysed material. The genus Candida was widely distributed, with C. homilentoma, C. colliculosa-like, C. famata and C. colliculosa being the most prevalent. A few isolates did not fit the standard descriptions and probably some of them could be new biotypes or even new species. Three strains of black yeasts were also isolated, and four others were identified as being Candida spp. The effective number of yeast species was higher in newer sponge. The origin, distribution and relative importance of these microorganisms for the ants are discussed.

Occurrence of killer yeasts in leaf-cutting ant nests

Killer activity was screened in 99 yeast strains isolated from the nests of the leaf-cutting ant Atta sexdens against 6 standard sensitive strains, as well as against each other. Among this yeast community killer activity was widespread since 77 strains (78 %) were able to kill or inhibit the growth of at least one standard strain or nest strain. Toxin production was observed in representatives of all the studied genera including Aureobasidium, Rhodotorula, Tremella and Trichosporon, whose killer activity has not yet been described.

Identificação de espécies fúngicas nas onicomicoses do idoso institucionalizado

BACKGROUND: Superficial fungal infections are caused by dermatophytes, yeasts or filamentous fungi. They are correlated to the etiologic agent, the level of integrity of the host immune response, the site of the lesion and also the injured tissue. OBJECTIVE: The purpose of this study is to isolate and to identify onychomycosis agents in institutionalized elderly (60 years old +). METHODS: The identification of the fungi relied upon the com-bined results of mycological examination, culture isolation and micro cultures observation under light microscopy from nail and interdigital scales, which were collected from 35 elderly with a clinical suspicion of onychomycosis and a control group (9 elderly with healthy interdigital space and nails). Both groups were insti-tutionalized in two nursing homes in Sao Bernardo do Campo, SP, Brazil. RESULTS: The nail scrapings showed 51.40% positivity. Of these, dermatophytes were found in 44.40% isolates, 27.78% identified as Trichophyton rubrum and 5.56% each as Trichophyton tonsurans, Trichophyton mentagrophytes and Microsporum gypseum. The second more conspicuous group showed 38.89% yeasts: 16.67% Candida guilliermondii, 11.11% Candida parapsilosis, 5.56% Candida glabrata, and 5.56% Trichosporon asahii. A third group displayed 16.70% filamen-tous fungi, like Fusarium sp, Aspergillus sp and Neoscytalidium sp (5.56% each). The interdigital scrapings pre-sented a positivity rate of 14.29%. The agents were coincident with the fungi that caused the onychomycosis. In the control group, Candida guilliermondii was found at interdigital space in one person. CONCLUSION: Employing a combination of those identification methods, we found no difference between the etiology of the institutional-ized elderly onychomycosis from that reported in the literature for the general population. © 2013 by Anais Brasileiros de Dermatologia.

Descrição da diversidade de fungos associados a formigas Attini por método independente de cultivo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Qualidade microbiológica e ocorrência de leveduras em polpas congeladas de frutas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)