Produção de celulases e hemicelulases por pochonia Chlamydosporia e Aplicação na sacarificação de resíduos agroindustriais.

Abstract

Second generation ethanol, produced from lignocellulosic waste, represents an alternative to the use of fossil fuels, which are finite and harmful to the environment. Totransform into 2G ethanol, these residues must undergo enzymatic saccharification (hydrolysis), very often after the pre-treatment step, to be converted into fermentable monosaccharides (sugars). Currently, this process is only viable using commercial enzyme cocktails, which are expensive. As an alternative to this limiting factor, there is the production and investigation of homemadeenzyme extracts via solid state fermentation (SSF), using agroindustrial residues as substrates. In this context, this paper investigated, for the first time, the potential of the fungus Pochonia chlamydosporia in the production of cellulases (exoglucanase, endoglucanase and β-glucosidase) and hemicellulases (xylanase and β-xylosidase) by SSF in three substrates: wheat bran, sugarcane bagasse and corn cob. The data highlighted the production of β-glucosidase in wheat bran, with a peak production of 51 U/g in 168 hours of cultivation. This cocktail was characterized and showed stability invarious pH (3.5–7.5) and temperature (30–50ºC) ranges, with an optimum pH of 4.5 and an optimum temperature of 50ºC, highlighting its potential for application in enzymatic hydrolysis, a step carried out in this paper using both raw and pre-treated with organosolv sugarcane bagasse and corncob, with a peak production of 1.022 g/L of TDS in the pre-treated corncob. Furthermore, it was possible to observe an increase of 402.4% and 89.8% in TDS in hydrolysis using pre-treated corncob and sugarcane bagasse, comparedto the raw substrates. The results obtained are promising, as the enzyme cocktail presented physicochemical characteristics suitable for use in saccharification of lignocellulosic biomass and the pretreatment step proved to be highly effective for greater release of TDS.