Waste office paper: A potential biorefinery feedstock for microbial lipids for biodiesel production

Waste paper is one among the major municipal solid wastes, which has a potential to serve as renewable feedstock for the bio-refineries of fuels, chemicals and materials. In this study, waste office paper was evaluated for its potential to be used as a renewable feedstock for the production of microbial lipids for biodiesel. The effect of various parameters such as hydrolysis time, enzyme loading, mass of waste office paper, working volume of flask and agitation in enzymatic hydrolysis of pretreated waste office paper was investigated through statistical optimization using response surface methodology. The results suggested that the 92h, 50 FPU/g enzyme, 5% substrate, 50ml working volume156 rpm were the most suitable for high sugar yield from waste office paper. Further, waste office paper hydrolysate was used as a substrate for the lipid production by an oleaginous yeast Cryptococcus curvatus. The fatty acid methyl ester (FAME) profile revealed that palmitic acid, stearic acid and oleic acid were the dominant fatty acids in lipids of C. curvatus. Thus, this study suggested that the waste paper being the main constituent in the municipal solid waste could be reduced and utilized for the production of biodiesel.