Oil, chitosan, and ethanol production by dimorphic fungus Mucor indicus from different lignocelluloses

Abstract

AbstractBACKGROUNDMucor indicus is a dimorphic fungus capable of producing ethanol, with numerous advantages compared with Saccharomyces cerevisiae.RESULTSCellulose solvent‐ and organic solvent‐based lignocellulosic fractionation (COSLIF) enhanced the enzymatic hydrolysis yield and especially the initial hydrolysis rate. Effects of the fungal morphology on the major metabolites, i.e., ethanol and biomass ingredients (fatty acids and chitosan) were investigated. Purely yeast‐like form yielded 78–92% of the maximum theoretical ethanol yield with 0.43–0.64 g L−1 h−1 productivity, whereas fermentation by purely filamentous form resulted in the yield and productivity of 48–66% and 0.3–0.4 g L−1 h−1, respectively. Beside ethanol, the fungus produced a large amount of chitin‐chitosan (62–67% of the fungal alkali insoluble materials) in filamentous form, while the value was 41–45% for yeast‐like form. Furthermore, yeast‐like cells produced nutritionally valuable fatty acids at a rate higher than that by filamentous form (3.7 and 2.7%, respectively). Linoleic acid, a polyunsaturated omega‐6, was the dominant fatty acid available in the biomass with both morphologies.CONCLUSIONSThe fermentation products were significantly dependent on the fungus morphology but not on the lignocellulose type. Yeast‐like cells exhibited better performance in ethanol and oil production, whereas the filamentous cells produced higher amounts of chitosan. © 2015 Society of Chemical Industry