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Los macromicetos han adquirido gran interés por su importancia alimenticia, terapéutica y económica, razón por la cual es necesario enfocar esfuerzos en la búsqueda de optimizar su producción de biomasa. El presente trabajo buscó determinar y comparar el efecto de la fermentación líquida (FEL) y superficial (FeSup) sobre la producción de biomasa de Flammulina velutipes, Hypsizigus tessulatus y Grifola frondosa empleando 6 fuentes de nutrientes de bajo costo: harina de soja, trigo integral, maíz blanco, maíz amarillo precocido, salvado de trigo y semillas de linaza molida. Los resultados de la FeSup permitieron determinar que la especie de mayor crecimiento radial, indistintamente de la fuente de nutrientes, es F. velutipes seguida de H. tessulatus y por ultimo G. frondosa, sin embargo, en la FEL no se observa la misma tendencia. La comparación en la producción de biomasa empleando FEL y FeSup, evidenció que los resultados son dependientes de la técnica de cultivo y que la FeSup no puede ser empleada para la selección preliminar de hongos macromicetos, enfocada en la producción de biomasa por FEL.

In this work, a kinetic study of the extraction of phenolic compounds from the micelial biomass of Pleurotus ostreatus obtained by submerged fermentation of was carried out. The conversion factors from substrate to biomass (Yx/s), substrate to product (Yp/s) and biomass productivity (Px, and Pp) were calculated, with values of 0,39 g of biomass·g of glucose-1, 0,1 g of total phenols·g of glucose-1, 0,047 g of biomass·L-1 h-1 and 0,0006 g of phenols L-1 h-1, respectively. The growth data were adjusted to the Gompertz model with a coefficient of determination (R2) of 0,88, while the glucose consumption data adjusted better to a Logistic model with an R2of 0,95(p < 0,05). The kinetic parameters of the process were obtained, such as the specific growth rate (µ, 0.031 h-1) and the specific speed of glucose consumption (µg, 0,011 h-1). [ABSTRACT FROM AUTHOR]

Lipase production in submerged culture by four lipolytic filamentous fungi strains using soybean oil as only carbon and energy source was studied. Biomass concentrations between 12 and 20 mg/mL were achieved, with growth yields between 0,65 and 1,08, indicating that the composition of the medium and the carbon source used were satisfactory. The lipolytic enzyme activity was evaluated at pH 4,8 and 7, showing two peaks of activity, at 48 and 120 h, respectively. The selected strains with the highest enzymatic activity at 48 h were at pH 4,8 the ML5-32 and ML6-35 (580 and 584 U/L, respectively) and at pH 7,0 the MS2-8 (545 U/L), which showed appropriated results to continue with their study towards its potential industrial application. [ABSTRACT FROM AUTHOR]

Título en inglés: Influence of inoculum concentration on the cellulase and xylanase production by Aspergillus niger Resumen 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. Palabras clave: celulasa; xilanasa; cultivo sumergido; morfología; Aspergillus niger. Abstract 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. Key words: Cellulase; xylanase; submerged culture; morphology; Aspergillus niger.

Se evaluó el efecto de los campos eléctricos sobre el crecimiento del hongo Ganoderma lucidum [(W. Curt.: Fr.) P. Karst. Ganodermataceae] bajo condiciones de cultivo sumergido, con el objetivo de optimizar su producción de biomasa. Ganoderma lucidum fue expuesto a tres factores diferentes [tipo de campo eléctrico corriente alterna (AC), corriente continua (DC) y corriente pulsada (IM)]; intensidad del campo [siete intensidades de campo desde 0,0 kV cm-1] (cultivo control) hasta 3,0 kV cm-1; y periodo de estimulación [dependiendo de la fase de crecimiento del hongo, después de la inoculación día 0 (fase lag), día 3 (fase exponencial o log) y día 6 (fase estacionaria)]. Los resultados mostraron que la combinación del campo eléctrico AC, con una intensidad de 1,5 kV cm-1 y aplicado al día 3 presentaron una mejor producción de biomasa con una media de 35,6450 ± 0,6684 gl-1, mientras que la combinación de los tres factores tipo de campo eléctrico DC a una intensidad de 2,5 kV cm-1 y aplicado el día 6 presentaron una menor producción de biomasa con una media de 26,2950 ± 3,9926 gl-1. Los anteriores resultados muestran que según la combinación de los factores evaluados es posible estimular la producción de biomasa del hongo Ganoderma lucidum bajo condiciones de cultivo sumergido mediante la aplicación de campo eléctrico.The effect of electric fields on the growth of the fungus Ganoderma lucidum [(W. Curt.: Fr) P. Karst. Ganodermataceae] under submerged culture was evaluated in order to optimize the production of biomass. Ganoderma lucidum was exposed to three different factors, types of electric fields [alternating current (AC), direct current (DC) and pulsed current (IM)], field intensities from 0.0 kV cm-1 (control culture) to 3.0 kV cm-1, stimulation period depending on the growth phase of the fungus after inoculation: day 0 (lag phase), day 3 (exponential or log phase) and day 6 (stationary phase). Results showed that the combination of three factors: AC electric field at an intensity of 1.5 kV cm-1 applied at day 3 day the highest biomass production with an average of 35.6450 ± 0.6684 gl-1, whereas the combination of DC electric field at an intensity of 2.5 kV cm-1 applied at day 6 showed the lowest production of biomass with an average of 26.2950 ± 3.9926 gl-1. These results show that depending on the combination of evaluated factors, the production of biomass of the fungus Ganoderma lucidum in submerged culture conditions may be stimulated by applying electric fields.

Se evaluó el efecto de dos velocidades de agitación (80 y 100 rpm), dos fuentes de carbono (glucosa y sacarosa) y tres pH iniciales (5.5, 6.0 y 6.5) sobre la producción de fenoles totales, la actividad antioxidante, el crecimiento micelial y el consumo de sustrato de una cepa nativa de un hongo perteneciente al orden Poliporal en cultivo sumergido.El mayor crecimiento micelial se obtuvo al día 3 con un valor de 10 g/L a una velocidad de agitación de 80 rpm, sacarosa como fuente de carbono y pH inicial 5.5. La máxima producción de fenoles y actividad antioxidante se presentó este mismo día, alcanzando valores de 0.18 g GAE/L y 0.28 TEAC (mM/mL), respectivamente, para cualquiera de las dos velocidades de agitación evaluadas, con glucosa como fuente de carbono y con pH inicial 6.0 y/o 6.5 para fenoles y pH inicial 5.5 para actividad antioxidante.Palabras claves: actividad antioxidante, crecimiento micelial, cultivo sumergido, fenoles.

Comprehension of the basic aspects of entomopathogenic fungi development and detailed knowledge of nutritious requirements for their growth and sporulation are fundamental for mass production and commercialization. The objective of this study was to evaluate the production of blastospores in submerged culture medium and of conidia in biphasic culture of four native isolates and a B. bassiana strain showing potential for the control of Diaphorina citri (Hemiptera: Liviidae), which belong to the collection of the FCB-UANL Institute of Biotechnology, México. The experimental design was completely randomized and means were compared using Tukey test (p£0.05). In the liquid culture medium formulated with glucose and casamino acids, at 72 h, blastospore production had the highest (p£0.05) concentration for GHA strain (2.20×10-8 mL-1) and biomass of 26 gL-1, while the HIB-4 isolate showed the lowest blastospore production (p£0.05) (5.25×107 m L-1) and biomass of 7 g L-1. Isolate HIB-2 had 56 % germination in diatomaceous earth for support, being the highest value among the studied fungi. In solid hase (rice grain), at 14 d of incubation, HIB-4 isolate presented a production of 1.82×109 conidia g-1, and GHA strain producted was 2.35×108 conidia g-1. Viability was higher than 90 % for all fungi during 4 weeks of storing at 4 °C. Thus, it is feasible produce blastospores and conidia of native isolates of B. bassiana with the potential of controlling pests which affect the citrus-growing regions of México. [ABSTRACT FROM AUTHOR]

Se evaluó el efecto de dos velocidades de agitación (80 y 100 rpm), dos fuentes de carbono (glucosa y sacarosa) y tres pH iniciales (5.5, 6.0 y 6.5) sobre la producción de fenoles totales, la actividad antioxidante, el crecimiento micelial y el consumo de sustrato de una cepa nativa de un hongo perteneciente al orden Poliporal en cultivo sumergido.El mayor crecimiento micelial se obtuvo al día 3 con un valor de 10 g/L a una velocidad de agitación de 80 rpm, sacarosa como fuente de carbono y pH inicial 5.5. La máxima producción de fenoles y actividad antioxidante se presentó este mismo día, alcanzando valores de 0.18 g GAE/L y 0.28 TEAC (mM/mL), respectivamente, para cualquiera de las dos velocidades de agitación evaluadas, con glucosa como fuente de carbono y con pH inicial 6.0 y/o 6.5 para fenoles y pH inicial 5.5 para actividad antioxidante.Palabras claves: actividad antioxidante, crecimiento micelial, cultivo sumergido, fenoles.

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The aim of this study was to evaluate the production of blastospores and conidia of different native isolates and a strain of Isaria fumosorosea using different propagation techniques. Two liquid culture media of casamino acids and peptone as nitrogen sources and glucose as carbon source for both media cultures were respectively used in the production of blastospores, while for the production of conidia, the fungi were grown in potato dextrose agar; from these cultures, solutions of conidia to a concentration of 1×10 6 per milliliter were prepared to inoculate flasks with Sabouraud dextrose broth for the liquid phase of the biphasic culture, also known as preculture. Subsequently, rice grain bags were inoculated with the preculture and the conidia solutions, which were incubated for 14 days for solid fermentation and biphasic culture, respectively. The HIB-23 isolate recorded a concentration of 4.90×10 8 blastospores/ml in the casamino acid medium, while a concentration of 2.15×10 8 blastospores/ml was obtained in the peptone collagen medium. For the Pfr-612 strain, the conidia production in solid-state fermentation was 1.58×10 9 conidia/g, and for HIB-30 in the biphasic culture of 9.00×10 6 conidia/g. Solid-state fermentation proved to be the most effective method with an average of 1.09×10 9 conidia/g, whereas the biphasic culture was the least effective method with 2.76×10 6 conidia/g; no significant difference was reported for the submerged production media., (Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.)