Production of ethyl butyrate by a triple cascade process of the continuous submerged and solid state fermentation with corn stover
摘要
The gas lift bioreactor, the anaerobic fermentor and the anaerobic solid state fermentor were connected to continuously produce ethyl butyrate with corn stover as the substrate. The activities of the cellulase from the immobilized Aspergillus niger and the esterase from the immobilized Saccharomyces cerevisiae were 9.16 U/mL and 29.16 U/mL in the gas lift bioreactor. The hydrolysis ratio of the corn stover celluose was 55.4% in the solid-state fermentor. During the continuous fermentation from 40.0 h to 120.0 h, the ethyl butyrate concentrations were 30.55 g/kg. The ratios of the total butyrate to the total acetate and the total butyrate to the released glucose were 6.72 and 0.55. Without the involvement of the exogenous cellulase and esterase, the pretreated corn stover was efficiently hydrolyzed to continuously produce ethyl butyrate in the bioreactors cascade of the aerobic submerge and anaerobic solid state fermentation. Highlights Ethyl butyrate was produced by a cascade process of aerobic and anaerobic fermentation. In situ saccharification of corm stover and in situ esterification of ethanol and butyrate was achieved. Ethyl butyrate was continuously produced with corn stover as the substrate. The metabolism burden of transforming cellulose into ethyl butyrate was synergistically shared by three kinds of the microorganism.