Ethanol production by a filamentous fungal strain Byssochlamys fulva AM130 under alternating aerobic and oxygen-limited conditions

Abstract

Byssochlamys fulva AM130, a novel strain of filamentous fungus, could produce ethanol from glucose, xylose, and alkali pretreated rice straw (PRS), while the efficiencies were very low with PRS. Ethanol production of 11.84 g/L was attained by the fungus when grown in glucose, indicating that the limitations while growing on PRS were related to low hydrolytic efficiency. Enzyme profiling of the fungus showed 365 IU/ml of beta-glucosidase and 89 IU/ml of xylanase activity, while endoglucanase and filter paper activity were negligible, which accounts for the low hydrolytic efficiency. The fungus could survive for extended periods under oxygen-limited conditions and produce ethanol. The fungal mycelia could also be used for repeated cycles of anaerobic fermentation, wherein the ethanol yield improved with each consecutive cycle.