RESUMEN
We investigated the enzymatic complex produced by selected fungi strains isolated from the environment using the agro-industrial residues rice husk, soybean hull, and spent malt as substrates. Microbial growth was carried out in solid-state cultivation (SSC) and in submerged cultivations (SC) and the enzymatic activities of xylanase, cellulase, ß-xylosidase, and ß-glucosidase were determined. All substrates were effective in inducing enzymatic activities, with one strain of Aspergillus brasiliensis BLf1 showing maximum activities for all enzymes, except for cellulases. Using this fungus, the enzymatic activities of xylanase, cellulase, and ß-glucosidase were generally higher in SSC compared to SC, producing maxima activities of 120.5, 25.3 and 47.4 U g-1 of dry substrate, respectively. ß-xylosidase activity of 28.1 U g-1 of dry substrate was highest in SC. Experimental design was carried out to optimize xylanase activity by A. brasiliensis BLf1 in SSC using rice husk as substrate, producing maximum xylanase activity 183.5 U g-1 dry substrate, and xylooligosaccharides were produced and characterized. These results suggest A. brasiliensis BLf1 can be used to produce important lytic enzymes to be applied in the preparation of xylooligosaccharides.
Asunto(s)
Proteínas Fúngicas/metabolismo , Hongos/crecimiento & desarrollo , Glucuronatos/biosíntesis , Glycine max/microbiología , Oligosacáridos/biosíntesis , Oryza/microbiología , Aspergillus/enzimología , Técnicas de Cultivo Celular por Lotes , Celulasa/metabolismo , Medios de Cultivo/química , Fermentación , Hongos/enzimología , Hongos/aislamiento & purificación , Filogenia , Especificidad por Sustrato , Xilosidasas/metabolismo , beta-Glucosidasa/metabolismoRESUMEN
The elephant grass has wide genetic variability reflecting in a large morphological plasticity within species. Therefore, this study aimed to evaluate the initial development of 73 genotypes of elephant grass at Campos-RJ. The characteristics studied were: plant height, number of tillers per meter and stem diameter. The experiment was conducted in a randomized block design with two replications in Pesagro Rio. Five evaluations were performed at four weeks intervals, the first of which occurred eight weeks after seeding. Data were tested for group averages, Scott Knott (1974) (P 0.01) and the regression analysis of first grade (P 0.05), allowing the grouping effect of the regression coefficients (1). Based on the average values of the characteristics evaluated genotypes: BAGCE 2, Cuban Pinda, Vrukwona, BAGCE 51, Capim Cana D"Africa, Cuba-116, King Grass, Purple Botucatu, Cameroon, BAGCE 69, IJ 7139, 02 AD IRI , BAG BAG 86 and 87 stood out from the rest. Based on the regression coefficient was possible to separate groups of genotypes with development patterns and identify those with the next highest speed budding buds and growth translated into higher speed of establishment of capineira.
O capim-elefante apresenta ampla variabilidade genética, refletida em uma grande plasticidade morfológica dentro da espécie. Assim, este estudo objetivou avaliar os efeitos de genótipo, idade e interação entre estes dois fatores sobre a altura de planta, número de perfilhos por metro linear e diâmetro de colmo, durante o desenvolvimento inicial de 73 genótipos de capim-elefante em Campos dos Goytacazes - RJ. O experimento foi conduzido em delineamento de blocos completos casualizados com duas repetições, no Campo experimental do Centro Estadual de Pesquisa em Agroenergia e Aproveitamento de Resíduos, pertencente à Empresa de Pesquisa Agropecuária do Estado do Rio de Janeiro (Pesagro-Rio). Foram realizadas cinco avaliações com intervalos de quatro semanas, sendo que a primeira ocorreu oito semanas após o plantio. Os dados foram submetidos ao teste de agrupamento de médias de Scott Knott (1974) (P 0,01) e à análise de regressão de primeiro grau (P 0,05), possibilitando efetuar o agrupamento dos coeficientes de regressão (1). Com base nos valores médios das características avaliadas, os genótipos BAGCE 2, Cubano Pinda, Vrukwona, BAGCE 51, Capim Cana D"África, Cuba-116, King Grass, Roxo Botucatu, Cameroon, BAGCE 69, IJ 7139, 02 AD IRI, BAG 86 e BAG 87 se destacaram dos demais. Baseado no coeficiente de regressão foi possível separar grupos de genótipos com padrões de desenvo