Second generation bioethanol production from hemicellulolytic hydrolyzate of apple pomace by Pichia stipitis

Investigation of novel feedstocks and microorganisms is very important for bioethanol production. Bioethanol production from hemicellulolytic hydrolyzate of the apple pomace was aimed in this study. Effects of some critical parameters such as biomass loading (5, 10, 15% w/v), supplements (nitrogen and mineral sources), and enzymatic hydrolysis on bioethanol production were optimized. The highest theoretical ethanol yield was observed as 84.1%, and Pichia stipitis produced 14.36 g/L bioethanol in the presence of the 10% (w/v) apple pomace loading. This is the first report about the enzymatic hydrolysis of the liquid fraction of apple pomace for bioethanol production by Pichia stipitis.