Biotecnologias aplicadas a produção de bioóleo e biodiesel a partir de bagaço de cana-de-açúcar.

Abstract

Biodiesel is a promising fuel to substitute diesel, with lower carbon emissions and is produced from renewable resources. Sugarcane bagasse is a type of lignocellulosic biomass waste produced from the manufacture of sugar and alcohol. The aim of this study was to evaluate the degrading potential of lignocellulosic biomass by microbial enzym es and to produce biodiesel from sugarcane bagasse with a biotechnological process using a lipid accumulate yeast. Sugarcane bagasse pre treated by steam explosion was subjected to enzymatic hydrolysis using crude enzyme from Trichoderma SG2 (T SG2) with or without supplementation with a commercial enzyme (Cellic CTec2). The synergy of Trichoderma SG2 cellulase and xylanase with the commercial enzyme Cellic CTec2 was promising in obtaining sugars from pre treated sugarcane bagasse. A mult istage hydrolysis process presented better results when proceeding with a complete separation of the fractions and with the replacement of enzyme, the values obtained in each stage being 24.98gL 1 of sugar in the first, 26.92gL 1 of sugar in the second. In the last stage of hydrolysis of residual biomass, 26.23gL 1 of sugar were recorded; thus, maximizing the production of fermentable sugars from bagasse. The cultivation of the Rhodotorula R1 in enzymatic hydrolyzate (BH) of sugarcane bagasse for lipid prod uction was evaluated. The enrichment of the hydrolyzate enzyme with commercial glucose promoted an increase in the accumulation of lipids, recovering 7.69% of lipids, using a culture medium containing 20gL 1 of peptone, 20gL 1 of commercial sugar and 0.93g L 1 of nitrogen (BH+P 20 D 20 /N 0.93 ). Lipid accumulation increased to 10.50% at a high carbon nitrogen ratio (BH+Y 10 D 20 /N 0.2 ), with the composition of the medium being 10gL 1 of yeast extract, 20gL 1 of commercial sugar and 0.2gL 1 of nitrogen. The lipids pro duced by Rhodotorula species R1 are mainly composed of long chain fatty acids, the main ones being Elaidic, Palmitic and Stearate (C16 e C18). Similar fatty acids are found in vegetable oils currently used for biodiesel production and indicate that yeast lipids are suitable for biodiesel production from raw materials.