Expression of β-glucosidase An-bgl3 from Aspergillus niger for conversion of scopolin / 生物工程学报

Scopoletin is a coumarin compound with various biological activities including detumescence and analgesic, insecticidal, antibacterial and acaricidal effects. However, interference with scopolin and other components often leads to difficulties in purification of scopoletin with low extraction rates from plant resource. In this paper, heterologous expression of the gene encoding β-glucosidase An-bgl3 derived from Aspergillus niger were carried out. The expression product was purified and characterized with further structure-activity relationship between it and β-glucosidase analyzed. Subsequently, its ability for transforming scopolin from plant extract was studied. The results showed that the specific activity of the purified β-glucosidase An-bgl3 was 15.22 IU/mg, the apparent molecular weight was about 120 kDa. The optimum reaction temperature and pH were 55 ℃ and 4.0, respectively. Moreover, 10 mmol/L metal ions Fe2+ and Mn2+ increased the enzyme activity by 1.74-fold and 1.20-fold, respectively. A 10 mmol/L solution containing Tween-20, Tween-80 and Triton X-100 all inhibited the enzyme activity by 30%. The enzyme showed affinity towards scopolin and tolerated 10% methanol and 10% ethanol solution, respectively. The enzyme specifically hydrolyzed scopolin into scopoletin from the extract of Erycibe obtusifolia Benth with a 47.8% increase of scopoletin. This demonstrated that the β-glucosidase An-bgl3 from A. niger shows specificity on scopolin with good activities, thus providing an alternative method for increasing the extraction efficiency of scopoletin from plant material.

Aspectos clínicos asociados al diagnóstico y tratamiento de la aspergilosis laríngea en pacientes inmunocompetentes / Clinical aspects associated with the diagnosis and treatment of laryngeal aspergillosis in immunocompetent patients

INTRODUCCIÓN. La aspergilosis laríngea en individuos inmunocompetentes, aunque rara, se reporta cada vez con más frecuencia; por lo cual, es necesario comprender mejor los aspectos clínicos y terapéuticos más adecuados para abordar su atención. OBJETIVO. Documentar los aspectos clínicos asociados al diagnóstico y el tratamiento de la aspergilosis laríngea en sujetos inmunocompetentes. METODOLOGÍA. Se realizó un estudio Bibliográfico Narrativo de carácter retrospectivo, donde se evaluaron los casos clínicos reportados de personas inmunocompetentes con aspergilosis laríngea desde el año 1983 hasta el 2022. Se hizo una revisión bibliográfica en las bases de datos PubMed/Medline y ScienceDirect, y se incluyeron todos los casos reportados en sujetos inmunocompetentes. RESULTADOS. Se identificaron 30 casos clínicos que cumplieron con los criterios de inclusión dentro de un grupo de 586 artículos revisados. El patógeno más reportado fue Aspergillus fumigatus y la evaluación histopatológica la principal herramienta para diagnosticar la aspergilosis. Se reportaron más casos en mujeres con un 58%. La mayor incidencia se observó en sujetos entre 20 y 49 años de edad. Los síntomas más comunes fueron disfonía, disnea y tos. El tratamiento farmacológico empleado actualmente es el Itraconazol seguido por el Voriconazol. CONCLUSIONES. La evidencia reportada mostró que la aspergilosis laríngea en pacientes inmunocompetentes podría estar dejando de ser un evento "poco común" por lo que debe prestarse más atención a su diagnóstico y tratamiento.

INTRODUCTION. Laryngeal aspergillosis in immunocompetent individuals, although rare, is reported with increasing frequency; therefore, it is necessary to better understand the most appropriate clinical and therapeutic aspects to address its care. OBJECTIVE. To document the clinical aspects associated with the diagnosis and treatment of laryngeal aspergillosis in immunocompetent subjects. METHODOLOGY. A retrospective Narrative Bibliographic study was performed, where clinical case reports of immunocompetent subjects with laryngeal aspergillosis from 1983 to 2022 were evaluated. A literature review was performed in PubMed/Medline and ScienceDirect databases, and all reported cases in immunocompetent subjects were included. RESULTS. Thirty clinical cases that met the inclusion criteria were identified from a pool of 586 articles reviewed. The most reported pathogen was Aspergillus fumigatus and histopathologic evaluation the main tool for diagnosing aspergillosis. More cases were reported in women with 58%. The highest incidence was observed in subjects between 20 and 49 years of age. The most common symptoms were dysphonia, dyspnea and cough. The pharmacological treatment currently used is Itraconazole followed by Voriconazole. CONCLUSIONS. The evidence reported showed that laryngeal aspergillosis in immunocompetent patients may no longer be a "rare" event and more attention should be paid to its diagnosis and treatment.

Methods of plant growth-promoting fungi application to enhance the growth and yield of wheat var. Ibaa99

Aims@#The main aim of the study was to evaluate some methods of application of Aspergillus niger AD1 and Trichoderma hamatum T-113 for enhancing the growth and yield of wheat var. Ibaa99 in pots and field conditions.@*Methodology and results@#Plant growth-promoting fungi (PGPF) loaded with peat moss were used at a rate of 100, 150 and 200 mL pot-1 or m-2 in filed soil; seed treatment (coating) with fungi suspension 19 × 107, soil treatment and combination of all the three methods was employed in the study. Wheat seeds were sown in pots and field plots during 2018-2019, and data regarding various growth and yield attributes were recorded. In both pot and field trials, the results revealed that the best treatments for the desired plant growth and yield attributes were peat moss 150 mL alone or in combination with soil and seed treatments. The soil physicochemical parameters were also improved after inoculation with selected fungal isolates in different application methods compared with un-inoculated control treatment in both pot and field conditions.@*Conclusion, significance and impact of study@#The PGPF play a vital role represented phytoremediation, phytostimulation and bio-fertilization. The isolates of PGPF, which were applied with peat moss at 150 mL to the pot and in the field alone or combined with seed treatment and soil application, were significantly the best effective method for improving wheat attributes.

An efficient marker-free genome editing method for Aspergillus niger / 生物工程学报

Aspergillus niger is an important industrial strain which has been widely used for production of enzymes and organic acids. Genome modification of A. niger is required to further improve its potential for industrial production. CRISPR/Cas9 is a widely used genome editing technique for A. niger, but its application in industrial strains modification is hampered by the need for integration of a selection marker into the genome or low gene editing efficiency. Here we report a highly efficient marker-free genome editing method for A. niger based on CRISPR/Cas9 technique. Firstly, we constructed a co-expression plasmid of sgRNA and Cas9 with a replication initiation region fragment AMA1 (autonomously maintained in Aspergillus) by using 5S rRNA promoter which improved sgRNA expression. Meanwhile, a strain deficient in non-homologous end-joining (NHEJ) was developed by knocking out the kusA gene. Finally, we took advantage of the instability of plasmid containing AMA1 fragment to cure the co-expression plasmid containing sgRNA and Cas9 through passaging on non-selective plate. With this method, the efficiency of gene editing reached 100% when using maker-free donor DNA with a short homologous arm of 20 bp. This method may facilitate investigation of gene functions and construction of cell factories for A. niger.

Process optimization for enhanced production of cellulases form locally isolated fungal strain by submerged fermentation

Cellulase has myriad applications in various sectors like pharmaceuticals, textile, detergents, animal feed and bioethanol production, etc. The current study focuses on the isolation, screening and optimization of fungal strain through one factor at a time technique for enhanced cellulase production. In current study sixteen different fungal cultures were isolated and the culture which quantitatively exhibits higher titers of cellulase activity was identified both morphologically and molecularly by 18S rDNA and designated as Aspergillus niger ABT11. Different parameters like fermentation medium, volume, temperature, pH and nutritional components were optimized. The highest CMCase and FPase activities was achieved in 100ml of M5 medium in the presence of 1% lactose and sodium nitrate at 30 oC, pH5 after 72 hours. The result revealed A. niger can be a potential candidate for scale up studies.

Phytochemical profile and antifungal action of Anadenanthera colubrina extract on the quality of maize seeds

Maize (Zea mays L.) is among the most cultivated crops in the world and can be affected by several diseases, especially those transmitted by seeds. The study of alternatives to fungicides used for seed treatment has a promising field in essential oils. Thus, this study determined the phytochemical profile of the ethanolic extract from Anadenanthera colubrina (Vell.) Brenan and to evaluate its antifungal activity on the sanitary and physiological quality of maize seeds. The seeds used were of the Jaboatão cultivar, which were submitted to the following treatments: control (untreated seeds), commercial fungicide (dicarboximide) and A. colubrina extract at 200, 400, 600, 800, and 1,000 ppm. The seeds were subjected to sanitary and germination tests in a completely randomized experimental design. Phytochemical prospecting of A. colubrina extract indicated the presence of alkaloids, tannins, flavonoids and saponins, as well as the major compounds lupeol, gallic acid, ferulic acid, catechin and quercetin. The A. colubrina extract reduced the incidence of Aspergillus spp., including Aspergillus niger, Alternaria spp., Curvularia spp. and Fusarium spp. at all concentrations. The highest concentrations (800 and 1,000 ppm) of the A. colubrina extract reduced the incidence of Penicillium spp. and yielded an effective control of Rhizoctonia spp. The extract of A. colubrina did not present phytotoxic effect, guaranteeing the viability and vigor of maize seeds.

Biomass of unconventional plants from Brazilian semiarid as substrate for hydrolytic enzymes production by Aspergillus niger under solid and submerged fermentation

Aspergillus niger KIJH was grown in solid and submerged fermentation using leaves and roots (with and without bark) of plants typically from Brazilian semiarid as substrate to produce a multienzymatic extract, which was characterised for its potential biotechnological applications. Solid-state fermentation (SSF) was applied to select the most promising plants biomass as induction substrates for the production of hydrolytic enzymes by fungus. The best biomasses were used as substrate in submerged fermentation (SmF) assays at two scales. Samples of up scale fermented culture were partially purified by ultrafiltration and activity and pH and temperature stability of CMCase and xylanase were evaluated. A. niger KIJH produced hydrolytic enzymes under SSF containing unconventional plants biomass from Brazilian semiarid. In SmF conditions, maximum CMCase (0.264 U mL-1) and xylanase (1.163 U mL-1) activities were induced by Jacaratia corumbensis. Scaling up the SmF to 500 mL of medium was able to maintain constant the production of CMCase (0.346 U mL-1) and xylanase (1.273 U mL-1) on the fermented culture. Ultrafiltered and concentrated extract presented CMCase activities practically constant in all temperature ranges (30-80°C) and pH (3.0-9.0), while xylanase optimum activity temperature was 50°C and pH in the range of 3.0 to 5.0. CMCase activity remained stable for 24 hours at 50°C

CRISPR/Cas-based genome editing in Aspergillus niger / 生物工程学报

Aspergillus niger is a vital industrial workhouse widely used for the production of organic acids and industrial enzymes. This fungus is a crucial cell factory due to its innate tolerance to a diverse range of abiotic conditions, high production titres, robust growth during industrial scale fermentation, and status as a generally recognized as safe (GRAS) organism. Rapid development of synthetic biology and systems biology not only offer powerful approaches to unveil the molecular mechanisms of A. niger productivity, but also provide more new strategies to construct and optimize the A. niger cell factory. As a new generation of genome editing technology, the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR associated (Cas) system brings a revolutionary breakthrough in targeted genome modification for A. niger. In this review, we focus on current advances to the CRISPR/Cas genome editing toolbox, its application on gene modification and gene expression regulation in this fungal. Moreover, the future directions of CRISPR/Cas genome editing in A. niger are highlighted.

Monitoramento de fungos anemófilos no ambiente de uma biblioteca no Município de São José do Rio Preto - Sp, Brasil / Anemophilic fungi monitoring in a library environment in the city of São Jose do Rio Preto, Brazil

Os fungos desempenham vários papéis que impactam a humanidade de diversas maneiras. Suas características metabólicas são importantes na biotecnologia, porém, tais microrganismos podem desencadear alguns problemas de saúde pública e até mesmo serem letais. Objetivo: detectar a presença de fungos no acervo de uma biblioteca no município de São José do Rio Preto. Metodologia: foram coletadas quarenta amostras nas superfícies inanimadas (livros, estantes, documentos, mapas, artigos e revistas) das principais salas da biblioteca com o auxílio de swabs umedecidos em solução salina estéril, posteriormente encaminhados ao laboratório de Biomedicina da Universidade Paulista ­ UNIP. As amostras foram semeadas em meio de cultura ágar Sabouraud Dextrose (SDA), tendo adicionado cloranfenicol e incubadas a 30 °C. Foi realizada a colônia gigante em todas as cepas crescidas em SDA para a realização da técnica de microcultivo para a identificação dos fungos, de acordo com o Manual de Detecção e Identificação dos Fungos de Importância Médica da Agência Nacional de Vigilância Sanitária. Resultados: Houve positividade em trinta e uma amostras (78%) e em quatro delas foi observado mais de um tipo de colônia (13%). Das vinte e duas superfícies de livros analisadas, foram isolados e identificados: Aspergillus flavus, Aspergillus niger, Cunninghamella sp., Cladosporium sp., Curvularia sp., Mucor sp. e Nigrospora sp. Nas oito superfícies de estantes: Aspergillus flavus, Aspergillus niger, Aspergillus versicolor, Penicillium sp. e Scopulariopsis sp. e, nos dez documentos: Aspergillus nidulans, Aspergillus sp., Cladosporium sp., Cunninghamella sp. e Trichoderma sp. Conclusão: Os fungos encontrados estão amplamente distribuídos no ambiente como solo e ar e, por diversos fatores, instalam-se em locais como bibliotecas. Em condições favoráveis, podem infectar o homem e causar perdas patrimoniais para os acervos.

Fungi play many roles that impact humankind in different ways. Their metabolic characteristics are important in biotechnology; however, these microorganisms can trigger some public health problems or may even be lethal. Objective: detect the presence of fungi in the collection of a public library in the city of São José do Rio Preto, Brazil. Methods: a total of forty samples were collected from inanimate surfaces (books, shelves, documents, maps, articles and magazines) located in the main rooms of the library with swabs soaked in sterile saline solution and sent to the Universidade Paulista ­ UNIP laboratories. The samples were plated in Sabouraud Dextrose Agar (SDA) supplemented with chloramphenicol and incubated at 30 °C. The colonies that grew in SDA were isolated in Potato Dextrose Agar for performing the slide culture technique for the identification of the fungi, performed according to the Manual of Detection and Identification of Fungi of Medical Importance from the Brazilian Health Surveillance Agency (ANVISA). Results: Thirty-one samples (78%) were positive, and in four of them more than one fungus genus was observed (13%). From the twenty-two book surfaces analyzed, the following fungi were isolated and identified: Aspergillus flavus, Aspergillus niger, Cunninghamella sp., Cladosporium sp., Curvularia sp., Mucor sp. and Nigrospora sp. On the eight shelves: Aspergillus flavus, Aspergillus niger, Aspergillus versicolor, Penicillium sp. and Scopulariopsis sp. The ten documents analyzed presented the following fungi: Aspergillus nidulans, Aspergillus sp., Cladosporium sp., Cunninghamella sp. and Trichoderma sp.. Conclusion: These fungi are widely distributed in the environment such as in the soil and air, and due to several factors, they colonize public places, such as libraries. In favorable conditions, they may infect humans and cause diseases.

Improved protease activity of Pixian broad bean paste with cocultivation of Aspergillus oryzae QM-6 and Aspergillus niger QH-3

BACKGROUND: The preparation of broad bean koji is a key process in the production of Pixian broad bean paste (PBP). Protease is essential for the degradation of proteins during PBP fermentation. To obtain broad bean koji with high protease activity using the cocultivated strains of Aspergillus oryzae QM-6 (A. oryzae QM-6) and Aspergillus niger QH-3 (A. niger QH-3), the optimization of acid and neutral protease activities was carried out using Box­Behnken design with response surface methodology (RSM). RESULTS: The optimum conditions were found to be as follows: inoculation proportion (X1), 3:1 (A. oryzae QM-6: A. niger QH-3, w/w); culture temperature (X2), 33°C; inoculum size (X3), 0.5% (w/w); incubation time (X4), 5 d. The acid and neutral protease activities were 605.2 ± 12.4 U/g and 1582.9 ± 23.7 U/g, respectively, which were in good agreement with the predicted values. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles revealed that the broad bean koji extracellular proteins in the case of cocultivation were richer compared to those in the case of A. oryzae QM-6 or A. niger QH-3 strain only. In addition, the free amino acids (FAAs) in the fermentation product were 55% higher in the cocultivation process than in that involving only A. oryzae QM-6, further confirming the diversity of proteases in the fermentation products. CONCLUSIONS: The optimal conditions of koji-making in PBP were obtained using RSM. The cocultivation of A. oryzae and A. niger increases the overall enzyme activities in the culture medium and the FAAs content, which would thus have potential application in the PBP industry.

Purification and physicochemical characterisation of Aspergillus niger USM F4 β-mannanase

Aims@#This present study focused on purification of fungal β-mannanase produced by Aspergillus niger USM F4 and also physicochemical characterisation of the purified enzyme.@*Methodology and results@#The purified β-mannanase with a molecular mass of ~47.4 kDa was demonstrated on SDSPAGE gel. The enzyme signified a purification degree of 4-fold, with final specific activity of 196.42 U/mg. It reached an optimum catalytic activity at pH 4.0 and 60 °C. The thermal stability of the enzyme was up to 70 °C and maintained the 50% activity after 30 min at 80 °C. Meanwhile, the pH stability was in the range of pH 3.0-9.0 and a 30 min half-life at pH 10.0. All chemical substances manifested an inhibitory effect on purified β-mannanase, with SDS (28.16 ± 0.05% residual activity) as the strongest inhibitor, followed by cupric ion (Cu2+) (49.51 ± 0.09% residual activity). As a whole, the enzyme displayed a substrate specificity in the order of locust bean gum (LBG) > carboxymethylcellulose > soluble starch > xylan from oat spelt > α-cellulose. Its preference for LBG has generated the Km and Vmax values of 0.20 mg/mL and 9.82 U/mL, respectively.@*Conclusion, significance and impact of study@#The outcomes of our study offer potential for use at industrial scales, particularly in the oligosaccharides production that involve acid-related activity, wide-ranging temperature and pH stability.

Biosorption potential of lead tolerant fungi isolated from refuse dumpsite soil in Nigeria

Metals are non-biodegradable and recurrent in the environs. Heavy metals tolerant fungiwere isolated from refuse dumpsite soil using pour plate method. These fungiwere identified as Aspergillus niger, Penicillium chrysogenumandRhizomucor sp. The fungal isolates were screened for cadmium (Cd), lead (Pb) and zinc (Zn) with concentration of 200ppm, 400ppm and 600ppm. Aspergillus nigerand Penicillium chrysogenumshowed high tolerance for the metals in contrast to the control. The fungiwith high tolerance were used for biosorption study. However, Penicillium chrysogenumshowed higher lead removal or biosorption potential of 1.07ppm, 3.35ppm and 4.19ppm as compared with Aspergillus nigerwith lead removal of 0.67ppm, 3.11ppm and 3.79ppm at 5th, 10thand 15thday respectively. One-way Analysis of Variance was used to interpret the data generated from the biosorption study which revealed that there was no significant different (p>0.05)between the lead removal of Aspergillus nigerandPenicillium chrysogenumon the 5thday but there was significant difference (p<0.05)in the lead removal of Aspergillus nigerand Penicillium chrysogenumon the 10thand 15thday. This study suggests the use of these fungal isolates for removal and biotreatment of heavy metal contaminated and polluted environment.

Enhanced production of ß- glucosidase by locally isolated fungal strain employing submerged fermentation / Aumento da produção de ß-glucosidase por estirpe fúngica isolada localmente, por fermentação submersa

ß-glucosidase has wide spectrum of biotechnological applications in different industries including food, textile, laundry detergents, pulp and paper, pharmaceutical and biofuel industry. The present investigation related to isolation, screening, and process optimization of fungal strain for enhanced production of ß-glucosidase (BGL). For this purpose, different fungal stains were isolated from different sources including soil, fruits, bark of tree as well as from the compost. The screening of fungal strain for BGL production was carried out via submerged fermentation. All the tested strains were identified on the basis of micro and macroscopic features. The fungal strain having greater ability for BGL synthesis among tested ones wasidentified as Aspergillus niger and given the code SBT-15. The process parameter including fermentation media, temperature, pH, rate of fermentation, carbon and nitrogen sources, volume of media were optimized. Five different fermentation media were evaluatedM3medium gave maximum production. The optimal conditions for BGL production was 72 hours of incubation at 40°C, pH 6 and 50 ml fermentation medium. Glucose (1%) and ammonium sulphate(3%) were optimized as best carbon and nitrogen sources, respectively.

A ß-glicosidase possui amplo espectro de aplicações biotecnológicas em diferentes indústrias, incluindo alimentos, têxteis, detergentes para lavanderia, papel e celulose, indústria farmacêutica e de biocombustíveis, etc. A presente investigação relaciona-se ao isolamento e triagem e otimização de processos de cepas fúngicas para produção aumentada de ß- glucosidase (BGL). Para este efeito, diferentes manchas fúngicas foram isoladas a partir de diferentes fontes, incluindo solo, frutos, casca de árvore, bem como a partir do composto. A triagem da linhagem fúngica para produção de BGL foi realizada via fermentaçãosubmersa. Todas as cepas testadas foram identificadas com base em características micro e macroscópicas. A linhagem fúngica com maior capacidade de síntese de BGL entre os testados foi identificada como Aspergillus niger e recebeu o código SBT-15. O parâmetro do processo, incluindo meios de fermentação, temperatura, pH, taxa de fermentação, fontes de carbono e nitrogênio, volume de mídia foram otimizados. Cinco meios de fermentação diferentes foram avaliados. O meio M3 deu a produção máxima. As condições ótimas para a produção de BGL foram 72 horas de incubação a 40 ° C, pH 6 e 50ml de meio de fermentação. Glicose (1%) e sulfato de amônio (3%) foram otimizados como melhores fontes de carbono e nitrogênio, respectivamente.

Efecto antifúngico y antimicotoxigénico de Lactobacillus plantarum CRL 778 a diferentes valores de actividad de agua / Antifungal and antimycotoxigenic effect of Lactobacillus plantarum CRL 778 at different water activity values

Ochratoxin A (OTA) is a mycotoxin produced by filamentous fungi with high impact Lactic acid bacteria; in food safety due to its toxicity. In the last decade, the presence of OTA was widely reported in different foods. In this study, the ability of Lactobacillus (L.) plantarum CRL 778 to control growth and OTA production by Aspergillus (A.) niger 13D strain, at different water activity (a w) values (0.955, 0.964, 0.971, 0.982, and 0.995) was determined in vitro. Both parame ters were significantly (p<0.05) reduced by the lactobacilli and the effect depended on a w. Greatest growth rate inhibition (46.9%) was obtained at a w = 0.995, which is the most suitable value for growth and production of antifungal metabolites (lactic acid, acetic acid, phenyllac-tic and hydroxyl-phenyllactic acids) by L. plantarum CRL 778. Besides, morphological changes and inhibition of melanin synthesis were observed in colonies of A. niger 13D in presence of L. plantarum CRL 778 at a w ranged between 0.971 and 0.995. In addition, maximum reduction (90%) of OTA production took place at a w = 0.971, while inhibition of fungi growth was more evident at a w =0.995. These findings suggest that L. plantarum CRL 778 could be used for control of ochratoxigenic fungal growth and OTA contamination in different fermented foods with a w values between 0.971 and 0.995.

Ocratoxina A (OTA) es una micotoxina producida por hongos filamentosos con un alto impacto en la seguridad alimentaria debido a su toxicidad. En la última década se ha reportado ampliamente a nivel mundial, la presencia de OTA en diversos alimentos. En este estudio se evaluó in vitro, la capacidad de Lactobacillus (L.) plantarum CRL 778 de controlar el crecimiento y la producción de OTA por Aspergillus (A.) niger 13D, a diferentes valores de actividad de agua (a w): 0.955, 0.964, 0.971,0.982 y 0.995). La cepa láctica redujo significativamente (p <0.05) ambos parámetros, siendo el efecto dependiente del valor de a w. La mayor inhibición del crecimiento (46.9%) se obtuvo a a w =0.995, valor más adecuado para el crecimiento y producción de metabolitos antifúngicos (ácido láctico, ácido acético, ácidos fenil-láctico e hidroxi-fenil láctico) por la cepa láctica. Además, se observaron cambios morfológicos en las colonias de A. niger 13D, crecidas en presencia de L. plantarum CRL 778 a valores de a w de 0.971 y 0.995. El porcentaje máximo de reducción en la producción de OTA (90%) por la cepa láctica se observó a un valor de a w = 0.971, mientras la inhibición del crecimiento fúngico fue mayor cuando a w = 0.995. Estos hallazgos sugieren que L. plantarum CRL 778 podría emplearse para el control de la contaminación por hongos ocratoxigénicos en alimentos con valores de aw comprendidos entre 0.971-0.995.

Lipase Production by Aspergillus niger C by Submerged Fermentation

Abstract This study aimed to evaluate the effects of variables on the process of lipases production by Aspergillus niger C by submerged fermentation (SmF). The production assays were performed in shake flasks for 72 hours at 150 rpm and 32°C. First, a fractional factorial design 25-1 (FFD) was carried out to evaluate the effect of the following process variables: sucrose, ammonium sulphate, soybean oil, yeast extract concentration and pH. After the selection of the variables that significantly influenced the lipase production, a central composite rotational design 22 (CCRD) was used, aiming to find the most favorable operational conditions. The selected assay condition (15.0 g.L-1 sucrose, 4.0 g.L-1 ammonium sulphate, 4.0 g.L-1 soybean oil and 1.0 g.L-1 yeast extract at pH 5.0) was the one that presented a lipase activity of 27.46 U.mL-1. It was very close to that best assay (30.76 U.mL-1), but using half of the inducer concentration, consequently reducing process cost. The kinetics of lipase production showed that the highest specific activity was 57.17 U.mg-1. The pH and temperature effects on lipase activity produced in this study was investigated. The optimum activity was found in a more acidic pH (5.0-6.0) and 55°C.

Application of an Enzymatic Extract from Aspergillus niger as Coagulant for Cheddar Cheese Manufacture

Abstract The coagulation of milk by a serin protease from Aspergillus niger NRRL3 was studied by rheology. Cheddar-type cheese was manufactured using 3.5% (v/v) of fungal enzymatic extract and fermentation-produced chymosin was used as control coagulant. Full composition and ripening of both kinds of Cheddar cheese were studied. Differences in the proteolysis of caseins, not only during cheese manufacture but also during ripening, affected cheese composition, texture and peptide profile. Microbial development during ripening was not affected by the coagulant used.

Antifungal efficiency of chemically and thermally-activated acrylic resins after surface treatment using poly (diallyldimethylammonium chloride)

Abstract INTRODUCTION: Acrylic resins are used in the preparation of facial prostheses and may be colonized by fungi. Here, we verified the antifungal efficacy of this material after surface treatment using poly (diallyldimethylammonium chloride). METHODS: Acrylic resin specimens with and without surface treatment were subjected to tests for fungistatic and fungicidal activities. Standard strains of Candida albicans and Aspergillus niger were used. RESULTS: After surface treatment, the fungistatic and fungicidal efficacies of the resins against C. albicans and fungistatic action against A. niger were verified. CONCLUSIONS: The surface treatment was a determinant of the antifungal activity of the material.

Antioxidant and Anti-inflammatory Capacity of Ferulic Acid Released from Wheat Bran by Solid-state Fermentation of Aspergillus niger / 生物医学与环境科学（英文）

OBJECTIVE@#A strain of Aspergillus niger (A. niger), capable of releasing bound phenolic acids from wheat bran, was isolated. This strain was identified by gene sequence identification. The antioxidant and anti-inflammatory capacity of ferulic acid released from wheat bran by this A. niger strain (FA-WB) were evaluated.@*METHODS@#Molecular identification techniques based on PCR analysis of specific genomic sequences were conducted; antioxidant ability was examined using oxygen radical absorbance capacity (ORAC), cellular antioxidant activity (CAA) assays, and erythrocyte hemolysis assays. RAW264.7 cells were used as a model to detect anti-inflammatory activity.@*RESULTS@#The filamentous fungal isolate was identified to be A. niger. ORAC and CAA assay showed that FA-WB had better antioxidant activity than that of the ferulic acid standard. The erythrocyte hemolysis assay results suggested that FA-WB could attenuate AAPH-induced oxidative stress through inhibition of reactive oxy gen species (ROS) generation. FA-WB could significantly restore the AAPH-induced increase in intracellular antioxidant enzyme activities to normal levels as well as inhibit the intracellular malondialdehyde formation. TNF-a, IL-6, and NO levels indicated that FA-WB can inhibit the inflammation induced by lipopolysaccharide (LPS).@*CONCLUSION@#Ferulic acid released from wheat bran by a new strain of A. niger had good anti-inflammatory activity and better antioxidant ability than standard ferulic acid.

Identification of Fungal Pathogens in Otomycosis and Their Drug Sensitivity: Our Experience

Abstract Introduction Otomycosis is a common problem in otolaryngology practice. However, we usually encounter some difficulties in its treatment because many patients show resistance to antifungal agents, and present high recurrence rate. Objectives To determine the fungal pathogens that cause otomycosis as well as their susceptibility to the commonly used antifungal agents. Additionally, to discover the main reasons for antifungal resistance. Methods We conducted an experimental descriptive study on 122 patients clinically diagnosed with otomycosis from April 2016 to April 2017. Aural discharge specimens were collected for direct microscopic examination and fungal culture. In vitro antifungal susceptibility testing was performed against the commonly used antifungal drugs. We tested the isolated fungi for their enzymatic activity. Results Positive fungal infection was found in 102 samples. The most common fungal pathogens were Aspergillus and Candida species, with Aspergillus niger being the predominant isolate (51%). The antifungal susceptibility testing showed that mold isolates had the highest sensitivity to voriconazole (93.48%), while the highest resistance was to fluconazole (100%). For yeast, the highest sensitivity was to nystatin (88.24%), followed by amphotericin B (82.35%), and the highest resistance was to terbinafine (100%), followed by Itraconazole (94.12%). Filamentous fungi expressed a high enzymatic ability, making them more virulent. Conclusion The Aspergillus and Candida species are the most common fungal isolates in otomycosis. Voriconazole and Nystatin are the medications of choice for the treatment of otomycosis in our community. The high virulence of fungal pathogens is owed to their high enzymatic activity. Empirical use of antifungals should be discouraged.

Process optimization for pectinase production by locally isolated fungal strain using submerged fermentation / Otimização de processos para produção de pectinase por cepa fúngica localmente isolada usando fermentação submersa

The present study deals with the isolation screening and optimization of fungal strain for pectinase production. The fungal strains were isolated from different sources, including soil, fruits etc. Qualitative screening was performed on the basis of the pectin hydrolysis zone. While, quantitative screening was carried out employing submerged fermentation. Among all the strains the strains showing highest pectinolytic potential were selected identified and assigned the code Aspergillus niger ABT-5.The influence of different fermentation media on pectinase production was evaluated. The M5 medium containing 10g wheat bran, nutrient medium containing (g/l) of (NH4)2SO4 6.0, K2HPO4 6.0, KH2PO4 6.0, MgSO4.7H2O 0.1 gave the highest pectinase production. The other important physico chemical parameters including incubation period, temperature, and volume of media, size of inoculum, carbon and nitrogen sources were also optimized for pectinase production. The highest pectinase production (15.5U/ml) was obtained at 72h of incubation, pH 6, temperature 30°C, volume of media 50ml. Fructose and urea were designated as best carbon and nitrogen sources subsequently.

O presente estudo trata da triagem de isolamento e otimização da cepa fúngica para produção de pectinase. As cepas fúngicas foram isoladas de diferentes fontes, incluindo solo, frutas, etc. A triagem qualitativa foi realizada com base na zona de hidrólise da pectina. Enquanto, a triagem quantitativa foi realizada utilizando fermentação submersa. Entre todas as cepas, as cepas que apresentaram maior potencial pectinolítico foram selecionadas e atribuídas ao código Aspergillus niger ABT-5. Avaliou-se a influência de diferentes meios de fermentação na produção de pectinase. O meio M5 contendo 10g de farelo de trigo, meio nutriente contendo (g / l) de (NH4)2SO4 6.0, K2HPO4 6.0, KH2PO4 6.0, MgSO4.7H2O 0.1, proporcionou a maior produção de pectinase. Os outros parâmetros físico-químicos importantes, incluindo período de incubação, temperatura e volume dos meios, tamanho do inóculo, fontes de carbono e nitrogênio também foram otimizados para a produção de pectinase. A maior produção de pectinase (15,5U / ml) foi obtida às 72h de incubação, pH 6, temperatura 30 ºC, volume dos meios 50ml. A frutose e a ureia foram designadas como melhores fontes de carbono e nitrogênio posteriormente.