An Environmentally Safe Production of Xylanases by Fusarium sp. EA 1.3.1 Using Agroindustrial Residues: Biochemical Characterization and Potential Applications

Renewable energy-related biotechnologies such as biofuels produced from low-cost residual sources that represent clean technologies have become a partial solution to environmental problems. We sought to optimize the cultivation parameters of the fungus Fusarium sp. EA1.3.1 and biochemically characterize the naturally produced xylanases from the fungus. The development of the fungus was analyzed considering the variations in the resources available and by biochemical analysis of the crude extract. The composition and duration of the cultivation, nitrogen source, carbon source, salt solution, and initial pH of the medium were evaluated. The maximum xylanolytic production was obtained in Khanna medium enriched with a CP salts solution during four days of culture using yeast extract, wheat bran, and an initial pH of 8.5 for the culture medium. The optimum temperature and pH were 65°C and 6.5, respectively, for the xylanase activity from Fusarium sp. EA 1.3.1. The enzymatic extract presented general stability at 50°C, keeping 75% of its activity after 90 minutes of incubation, and its activity decreased to 20-40% with exposure to higher temperatures (60-70°C). The enzyme also presented high stability at pH 5.0 after 90 minutes, maintaining 85% of its relative activity. Thus, the isolated fungus presents high potential for xylanase production with desired biochemical and biophysical properties for industrial application.