Hydrolyzed corn stover as a promising feedstock for 2‐phenylethanol production by nonconventional yeast

Abstract

Abstract BACKGROUND Plant biomass rich in lignocelluloses may be applicable for the production of highly valuable bioproducts. In this study, the use of hydrolyzed corn stover as a carbon source for yeast producing 2‐phenylethanol (2‐PE) is investigated. 2‐PE is an alcohol with a rosy scent, commonly used in the food and cosmetic industries as an aroma and preservative. The growing demand for this compound motivates the development of new methods of production. RESULTS The corn stover biomass was first pretreated with an alkaline solution of H 2 O 2 and secondly hydrolysed with a cellulolytic enzyme cocktail to cause the saccharification of polycarbohydrates and the release of fermentable monosugars. This resulted in saccharification yields of up to 88.1 ± 7.6% and 92.5 ± 9.1% related to cellulose (glucan) and hemicellulose (arabinoxylan) content, respectively. Next, the obtained hydrolyzates were used as a feedstock for 2‐PE production by two nonconventional yeasts, Metschnikowia chrysoperlae WUT25 and Pichia fermentans WUT36. The highest 2‐PE titer of 3.67 g L −1 was attained with the WUT36 strain. Finally, 2‐PE was extracted from the fermentation broth with ethyl acetate (100% recovery) and purified by distillation to 97.27 ± 0.08%. CONCLUSION This is the first report demonstrating the promising and complete route of 2‐PE production by yeast in a medium based on the hydrolyzate of corn stover. © 2018 Society of Chemical Industry