Eleni Gomes, Rafaela Brito, Roberto Da Silva, Ana Lucia Ferrarezi
Biodiesel is a biofuel alternative to petrodiesel with environmental and socio-economic benefits. It consists of alkyl esters obtained from transesterification of oils catalyzed by chemicals compounds (acids and bases) or enzymes. The transesterification catalyzed by lipase has the advantage of produce better quality biodiesel and still allows recovery of a purer glycerol. This study aimed to isolate and select filamentous fungi capable of producing lipase with transesterification activity. Among the 20 strains of fungi isolated, two produced lipases with transesterification activity when grown on solid state fermentation (SSF) using sugarcane bagasse and soybean meal (9:1) as substrate. The selected fungus Acremonium sp ROG 2.1.9 initially showed transesterification activity with a yield of 1.5 g of 100g-1 esters from soybean oil and hydrolytic activity of 3.8 U mL-1 but when the immobilized mycelia was used the yields increased to 4.7 g of esters 100g-1 oil. The Box-Behnken design used for evaluate the effect of different conditions for transesterification reaction resulted in an increase of 80% in the yield of biodiesel. The zymogram of activity showed the presence of lipases and hydrolytic transesterifying in crude enzyme solution.