Evaluation of endoglucanase and β-glucosidase production by bacteria and yeasts isolated from an eucalyptus plantation in the cerrado of Minas Gerais

Abstract

The current global environmental and economic scenario is intrinsically related to the increase in fossil fuel consumption caused by technological development and world population growth. Thus, it is necessary to search for renewable sources of biofuel in an attempt to mitigate the effects of fossil fuels on the environment and the lack of these non-renewable fuels. The use of lignocellulosic biomass, an abundant and renewable resource in Brazilian regions, has contributed successfully to new research and technologies for second-generation ethanol production. The conversion of lignocellulosic biomass into fermentable sugars requires the use of cellulolytic enzymes produced by microorganisms found in the microbiota. This work evaluated the production of endoglucanase and β-glucosidase in a liquid medium containing carboxymethylcellulose by five microorganisms (bacteria and yeasts) from the bank of 348 isolates from eucalyptus soils in the Cerrado Mineiro. Microorganisms with the following enzymatic activity indexes were selected: IM1-74 (22), IM25-9 (5.33), IM32-90 (7.33), IM1-5 (10.33) and IM32-91 (5.44). The microorganisms with the highest enzymatic activity in the liquid medium were IM32-90 (endoglucanase = 0.214 U mL^-1) and IM32-91 (β-glucosidase = 0.067 U mL^-1).