Variáveis que influenciam a produção de celulases e xilanase por espécies de Aspergillus

Abstract

Resumo -O objetivo deste trabalho foi determinar as variáveis que influenciam a produção simultânea de celulases e xilanase por Aspergillus aculeatus URM 4953 e A. phoenicis URM 4924, com uso de bagaço de cana-de-açúcar como substrato. As variáveis avaliadas foram pH inicial, tempo de cultivo, concentração do substrato, agitação, concentração do inóculo, temperatura, tipo de bagaço de cana-de-açúcar e espécie de Aspergillus. Foi utilizado o planejamento fatorial fracionário 2 , com três repetições no ponto central. Todas as variáveis analisadas influenciaram a produção de pelo menos uma das enzimas. As maiores atividades enzimáticas observadas foram: celulases totais, 0,45 UI mL . As melhores condições para produção das enzimas foram: pH 6,0; tempo de cultivo de 168 horas; bagaço de cana-de-açúcar residual como substrato; e A. aculeatus URM 4953, que produziu as celulases e a xilanase simultaneamente. As variáveis que influenciam a produção simultânea das celulases e xilanase são pH, tempo de cultivo, tipo de bagaço de cana-de-açúcar e espécie de Aspergillus.Termos para indexação: Aspergillus aculeatus, Aspergillus phoenicis, bagaço de cana-de-açúcar, celobiase, endoglucanase, exoglucanase. Variables that influence the production of cellulases and xylanase by Aspergillus speciesAbstract -The objective of this work was to determine the variables that influence the simultaneous production of cellulases and xylanase by Aspergillus aculeatus URM 4953 and A. phoenicis URM 4924, using sugarcane bagasse as substrate. Initial pH, cultivation time, substrate concentration, agitation, inoculum concentration, temperature, sugarcane bagasse type and Aspergillus species were the variables evaluated. It was used the 2 8-4fractional factorial design, with three replicates in the central point. All analysed variables influenced at least one of the enzyme production. The highest enzymatic activities were: total cellulases, 0.45 UI mL . The best conditions for enzyme production were: pH 6.0; cultivation time of 168 hours; residual sugarcane bagasse as substrate; and A. aculeatus URM 4953, which produced simultaneously all the cellulases and xylanase. The variables that influence the simultaneous production of cellulases and xylanase are pH, cultivation time, sugarcane bagasse type, and Aspergillus species.

Substract and temperature effect on xylanase production by aspergillus fumigatus using low cost agricultural wastes

“…The greatest biosynthesis of xylanase at 45 o C suggests that A. fumigatus SCB4 can be a thermotolerant fungal strain. Previous studies reported the effects of time and temperature during SSF on xylanase synthesis by other Aspergillus species and described higher production of xylanases at the same temperature (SALES et al, 2010, DELABONA et al, 2012. This peak of xylanase activity at 45 o C suggest that this mold can be employed in bioreactors at high temperatures, which could contribute to better conditions of operations, such as fluidity of the medium and reduction of the risk of contamination by mesophilic microorganisms (GOMES et al, 2007).…”

Bioprospecting Aspergillus section Nigri in Atlantic Forest soil and plant litter

“…niger, A. awamori, A. oryzae, A. nidulans, A. fumigatus, A. clavatus, A. glaucus, A. ustus, and A. versicolor (SLIVINSKI, 2007). Also in this genus, the species from the Nigri section have been extensively studied, as they are good producers of enzymes such as amylase, cellulose, pectinase, protease, and phytase (SALES et al, 2010;RODRÍGUEZ et al, 2011;REZENDE et al, 2012;MACIEL, 2013).…”

Sugarcane Biomass Production And Renewable Energy

“…Cellulases are enzymes that form a complex that hydrolyses cellulosic materials, releasing sugars [2]. The main component of hemicellulose is the xylan, which is hydrolyzed by xylanases [3]. Cellulases as xylanases have a great biotechnological potential, they can be used in a variety of field: food, animal feed, textile and paper recycling industries.…”