Isolation of Filamentous Fungi from the Caatinga Region and Production of Amylolytic Enzymes of Great Industrial Interest

The industrial importance and the high cost of the commercial amylase require the study of microorganisms that produce these enzymes. For this reason, the objective of this work was to isolate filamentous fungi from a region of the caatinga and evaluate their potential for the production of amylase. Four soil samples were collected from a deactivated dump located in the city of Diamantina, MG, in a region of the caatinga. The analysis of amylolytic production in a submerged medium at the ideal temperature of each microorganism was performed using the saccharification method, and the reducing sugars formed were quantified by DNS. Fourteen filamentous fungi were isolated, which had different morphological aspects. Regarding amylase production, a mean activity of 0.477 U·mL-1 was obtained with the isolates I 1.2.1 and I 4.4.1. These results bring important information regarding the biodiversity of the caatinga, in addition to the isolation of microorganisms that can be used as biological machinery to obtain metabolites with high biotechnological and industrial potential.

Immobilization in Spheres of a Cocktail Rich in Xylanase Produced by the Fungus <i>Fusarium sp</i>. EA 1.3.1 for Hydrolysis of Sugarcane Bagasse

Second generation ethanol is produced from the degradation of lignocellulosic biomass using enzymes as catalysts, with emphasis on xylanases. These biocatalysts are often costly, but stable at high temperatures, and their reuse is of great value, so the immobilization of the enzymes can increase their applicability on an industrial scale. We sought to immobilize a cocktail rich in xylanase produced by the fungus Fusarium sp. EA 1.3.1 in alginate spheres, optimize the immobilization method, characterize the immobilized derivatives, improve their physical-chemical characteristics, and perform the hydrolysis of sugarcane bagasse to release sugars. The Fusarium sp. EA 1.3.1 has been identified and used for cocktail rich in xylanase production that was immobilized in alginate spheres. During this process, the drip equipment, and the concentration of the solutions of sodium alginate and calcium chloride were evaluated. The best results were obtained with the glass rod and with concentrations of 3.14% and 2.10% for the solutions, respectively. The apparent optimum conditions of pH and temperature reaction were studied, and the values of pH 6.5 and 60°C were obtained. The immobilized conjugate also presented greater stability at this temperature than that of the soluble cocktail. The conjugate could be recycled up to six times, and its activity was maintained after 75 days of storage. Finally, the hydrolysis in natural sugarcane bagasse was achieved, and greater amounts of reducing sugars were obtained in the reaction with the conjugate. Thus, the cocktail rich in xylanase produced by the fungus Fusarium sp. EA1.3.1 was successfully immobilized on alginate spheres and possesses the potential to be used as a catalyst in industrial processes such as the lignocellulosic ethanol industry.