Valorization of jatropha fruit biomass for energy applications
SummaryMicrobial extraction of oil from Jatropha kernels using whole cells of Bacillus pumilus yields 73% oil. The oil is liberated via degradation of hemicelluloses in which the majority kernel proteins were preserved. In investigating the effect of dilute sulfuric acid pretreatment on the enzymatic digestibility of the lignocellulosic components of Jatropha fruit biomass, we found that the seed shell and the seed cake were more recalcitrant to dilute sulfuric acid pretreatments than the fruit hull. The fruit hull pretreated with dilute sulfuric acid at optimum conditions (10% solid loading, 0.9% sulfuric acid, 30 min, 178 oC) followed by neutralization and a 24-h enzymatic hydrolysis with cellulases (GC220) gave the hydrolyzate with high sugar content. The hydrolyzate can be used as a substrate to produce ethanol by Saccharomyces cerevisiae in SSF process.