Biodiesel synthesis directly catalyzed by the fermented solid of Burkholderia cenocepacia via solid state fermentation

Abstract

The objectives of this work were to evaluate the production of Burkholderia cenocepacia lipase via solid state fermentation (SSF) and its applications in atransesterification reactions through the direct addition of the lyophilized fermented solid to tert-butanol system. The maximal olive oil-hydrolyzing activity of fermented solid was 72.3 units per gram of dried fermented solid at 96h through adding 8% (v/w) olive oil as inducer during SSF. After lyophilization and delipidation, the whole fermented solid was directly employed to catalyze the ethanolysis of soybean oil for biodiesel production in tert-butanol. The highest biodiesel yield was 86% after 96h under the optimized conditions of 45°C, speed rate 200rpm, alcohol/oil molar ratio 4:1, fermented solid amount 1.5wt.% (based on oil weight, g), tert-butanol amount 40% ((based on oil volume, v/v) and moisture content 5wt.% (based on oil weight, g). This strategy of biodiesel production in this work shows potential alternative to lower down the lipase cost for enzyme-catalyzed transesterification reactions.