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This study attempts to describe the immunostimulatory effects of three fungal glucans on innate immunity responses in an in vitro assays using Pacific red snapper leukocytes. First, the yield glucans obtained was higher in Aspergillus niger, follow by Aspergillus ochraceus and Alternaria botrytis (40, 20 and 10%, respectively). Structural characterization of these fungal glucans by proton nuclear magnetic resonance (NMR) indicated structures containing (1-6)-branched (1-3)-ß-D-glucan. The immunostimulatory activity of fungal glucans were assessed in head-kidney leukocytes at 24 h using colorimetric assays and molecular gene expression. In addition, the response against bacterial infection using Aeromonas hydrophila was evaluated by flow cytometry with annexin V/propidium iodide. Leukocytes responded positively to fungal glucans where the viability was higher than 80%. Interestingly, A. niger ß-glucans enhanced the phagocytic ability and capacity in head-kidney leukocytes. Immunological assays reveled an increased in nitric oxide production, myeloperoxidase, superoxide dismutase and catalase activities, in fish stimulated with A. niger ß-glucans. Induction of cytokines (IL-1ß, TNF-α, IL-6, IL-8 and IL-12) were more pronounced in A. niger ß-glucans leukocytes stimulated compared to other group. Finally, flow cytometry assay showed that A. botrytis and A. niger ß-glucans were able to inhibit apoptosis caused by Aeromonas hydrophila in the Pacific red snapper leukocytes indicating an immunostimulant potent response by fungi derived-glucans. These results strongly support the idea that fungal ß-glucans can stimulate the immune mechanism in head-kidney leukocytes and that Aspergillus niger ß-glucan possess immunostimulatory properties cell increasing viability, and reducing necrotic cell death caused by Aeromonas hydrophila.

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Beta-glucan is a major component of fungal cell walls and shows various immunopharmacological activities including antitumor activity. Previously, we detected anti-beta-glucan antibody in human sera. Anti-beta-glucan antibody participates in the immune response to fungal cell wall beta-glucan. Patients on dialysis are at high risk of infection including fungal infections. We examined the plasma beta-glucan level and the titer of anti-beta-glucan antibody in dialysis patients. We measured plasma beta-1,3-glucan concentrations with the limulus G test and anti-beta-glucan antibody titers by ELISA with Candida beta-glucan-coated plates. We also examined the influence of the period of dialysis and the kind of dialysis membrane. The patients were positive for beta-1,3-glucan in their plasma. The anti-beta-glucan antibody titer was lower in the dialysis patients than in healthy volunteers. Long-term dialysis patients showed lower anti-beta-glucan antibody titers than short-term dialysis patients. No significant difference was found between the kinds of dialysis membrane. The titer of anti-beta-glucan antibody as recognition molecule of beta-glucan was low in dialysis patients compared with healthy volunteers. This is likely to be one factor explaining the sensitivity to infection of the dialysis patients. An appropriate application of culinary-medicinal mushroom such as Agaricus brasiliensis has potential for the prevention of fungal infection in dialysis patients.

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Existe un gran interés por el uso de enzimas lignocelulolíticas en varias industrias, y en la biodegradación de biomasa para la producción de biocombustibles y otras aplicaciones. Entre las fuentes microbianas de enzimas, Aspergillus niger es uno de los microorganismos más utilizados en la producción de enzimas industriales, debido a sus niveles altos de secreción de proteína y a su condición GRAS (generally regarded as safe). El objetivo del presente estudio fue evaluar la influencia de la concentración de inóculo en la morfología y producción de celulasas y xilanasas con A. niger en cultivo sumergido. Para ello, fueron inoculados matraces de 250 mL con 40 mL de medio con 3% (v/v) de una suspensión de 104 o 108 esporas por mililitro e incubados a 28 ºC y 175 rpm durante 120 horas. Se utilizaron 10 g*L-1 de lactosa como fuente de carbono. En cada caso se determinó la cantidad de biomasa, la proteína extracelular soluble, lactosa residual, actividad celulasa total y xilanasa cada 24 horas. Aunque no hubo un efecto notorio en la morfología de crecimiento, salvo en el color y el diámetro de pellets obtenidos, sí se afectó la µmax (0,06 y 0,03 h-1 para 104 y 108 esporas*mL-1, respectivamente) y la concentración máxima de biomasa. Además, mientras que las productividades volumétricas de celulasa (ΓFPA) (8,2 y 8,0 UI.*L-1*h-1 para 104 y 108 esporas*mL-1, respectivamente) fueron similares para ambos inóculos, la productividad de xilanasa (ΓXIL) fue mayor para el inóculo más concentrado (29,7 y 33,4 UI¨*L-1*h-1 para 104 y 108 esporas*mL-1, respectivamente). Los resultados indican que la productividad de celulasas y xilanasas está estrechamente relacionada con la concentración de inóculo.

There is a great interest for the use of lignocellulolytic enzymes in several industries and in biomass degradation for production of biofuels and other applications. Among the microbial sources of enzymes, Aspergillus niger is one of the most used microorganisms in the production of industrial enzymes due to its high levels of protein secretion and its GRAS (generally regarded as safe) condition. The aim of the present study was to evaluate the influence of A. niger inoculum concentration in the morphology and production of cellulases and xylanases in submerged cultures. For this, 250 mL flasks containing 40 mL culture medium were inoculated with a 3% (v/v) of either 104 or 108 spores per milliliter suspension and incubated at 28 º C and 175 rpm during 120 hours. Lactose (10 g*L-1) was used as the carbon source. In each case, the amount of biomass, the extracellular soluble protein, residual lactose, total celullase activity and xylanase activity were determined every 24 hours. Even thought there was not a notorious effect on the growth morphology, except in color and diameter of pellets; µmax was affected (0.06 and 0.03 h-1 for 104 and 108 spores*mL-1, respectively) as well as maximum biomass concentration. In addition, while the volumetric productivity of cellulase (8.2 and 8.0 UI*L-1*h-1 for 104 and 108 spores*mL-1, respectively) were similar for both inocula, the productivity of xylanase was greater for the more concentrated inoculum (29.7 and 33.4 UI*L-1*h-1 for 104 and 108 spores*mL-1, respectively).The results show that cellulase and xylanase productivities are closely related to the inoculum concentration.

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O sisal (Agave sisalana Perrine ex Engelm.) é a principal fonte de extração de fibras duras vegetais do mundo. No Brasil, o cultivo ocupa extensa área de solos pobres na região semi-árida dos Estados da Bahia, Paraíba e Rio Grande do Norte, em regiões com escassa ou nenhuma alternativa para exploração de outras culturas. Tendo em vista a propriedade inibitória dos extratos vegetais sobre o desenvolvimento de fungos, avaliou-se o efeito inibitório do extrato vegetal de alho (Allium sativum L.) sobre o fungo Aspergillus niger isolados da cultura do sisal. O extrato vegetal foi incorporado ao meio BDA fundente, aproximadamente 45ºC, nas concentrações 0, 500, 1000, 2000, 50000, 10000 e 50000 mg L-1. Os resultados demonstraram que a dose de 50000 mg L-1 de alho foi eficiente na inibição do crescimento do fungo Aspergillus niger "extraídos" da cultura do sisal.

Sisal (Agave sisalana Perrine ex Engelm.) is the main source of plant hard fiber extraction in the world. In Brazil, its cultivation occupies a large area of poor soils in the semi-arid region of Bahia, Paraiba and Rio Grande do Norte States, and in regions with scarce or no alternative to explore other crops. Based on the inhibitory property of plant extracts on fungal development, the inhibitory effect of garlic (Allium sativum L.) extract was evaluated on the fungus Aspergillus niger isolated from sisal crop. The plant extract was incorporated into melting PDA medium around 45ºC, at the following concentrations: 0, 500, 1000, 2000, 50000, 10000, and 50000 mg L-1. (OBS: M. Elena, há duas doses repetidas; creio que a primeira seja 5000). The concentration 50000 mg L-1 garlic extract was effective in inhibiting the growth of the fungus Aspergillus niger extracted from sisal crop.

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In this work we characterized the immune response of the insect Rhodnius prolixus to a direct injection into the hemocoel of the non-entomopathogenic fungus Aspergillus niger, and evaluated its consequences on host oogenesis. These animals were able to respond by mounting effective cellular and humoral responses to this fungus; these responses were shown, however, to have reproductive fitness costs, as the number of eggs laid per female was significantly reduced. The disturbance of egg formation during infectious process correlated with an elevation in the titer of hemolymph prostaglandin E2 48 h post-challenge. Administration of Zymosan A as an immunogenic non-infectious challenge produced similar effects on phenoloxidase and prophenoloxidase activities, oocyte development and prostaglandin E2 titer, precluding the hypothesis of an effect mediated by fungal metabolites in animals challenged with fungus. Ovaries at 48 h post-challenge showed absence of vitellogenic ovarian follicles, and the in vivo administration of prostaglandin E2 or its receptor agonist misoprostol, partially reproduced this phenotype. Together these data led us to hypothesize that immune-derived prostaglandin E2 raised from the insect response to the fungal challenge is involved in disturbing follicle development, contributing to a reduction in host reproductive output and acting as a host-derived adaptive effector to infection.

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Aspergillosis became an important opportunistic mycosis during the last years, with a great variety of clinical manifestations. To contribute to the replenishing of this mycosis serodiagnosis, biologic reactives (antigens and antisera) were prepared from strains of the species Aspergillus niger, Aspergillus flavus and Aspergillus terreus for their use in immunoprecipitation assays. The reactives were assessed by double immunospreading versus a reference commercial system; satisfactory results were obtained, and this guarantees the widening of the aspergillosis serodiagnosis in the Mycology Laboratory of the "Pedro Kourí" the Tropical Medicine Institute (IPK) with important imports savings.

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Foram investigadas as atividades antibacteriana e antifúngica dos extratos éter de petróleo e alcaloídico de folhas de Aristolochia gigantea Mart e Zucc, pelo método de difusäo em agar. O extrato éter de petróleo mostrou atividade contra uma bactéria Gram-positiva. O extrato alcaloídico apresentou atividade contra duas bactérias Gram-positivas. Uma Gram-negativa, näo apresentando qualquer atividade antifúngica.

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