Production of cellulase by Microbulbifer hydrolyticus through co-fermentation of glucose and xylose from lignocellulose

Abstract

Cellulase is a compound enzyme that catalyzes cellulose into monosaccharides or oligosaccharides. Large amounts of cellulase are needed with the development of the lignocellulose processing industry, which necessitates faster methods to produce cellulase. In this work, the marine bacterium Microbulbifer hydrolyticus IRE-31-192 was selected to produce cellulase, due to its fast growth rate and short high space-time yield. Co-fermentation of glucose and xylose to produce cellulase was investigated on the basis of previous work. When the ratio of glucose/xylose was 2:1 (w/w), 294 U/L cellulase activity with highest space-time yield of 12.2 U/L h was obtained. The hydrolytic liquid of lignocellulose prepared from dried distiller’s grains with solubles (DDGS) with the similar ratio of glucose/xylose was used as medium to produce cellulase. The efficiency of cellulase production from processed and unprocessed hydrolysates of DDGS was compared. Unprocessed hydrolysates were more beneficial for the production of cellulase, such that its activity was 261 U/L with a space-time yield of 14.5 U/L h. Thus, commonly used pure glucose and xylose could be replaced by hydrolysates of DDGS, and marine bacteria has potential application for cellulase production.

Applications of one-Step environmentally-friendly fermentation method to produce fumaric acid with immobilized Rhizopus arrhizus in stirred-tank reactor

“…Fumaric acid, an important four-carbon dicarboxylic acid, is an intermediate in the TCA cycle, and it is a building block to synthesize more complex compounds in the chemical, food processing, agriculture, and pharmaceutical industries (Guo et al 2020). Microbial fermentation using renewable biomass as raw material has the advantages of being environmentally friendly and sustainable (Abo et al 2019;Liu et al 2020). Rhizopus, Saccharomyces cerevisiae, Torulopsis glabrata, Escherichia coli, and their derivatives have been evaluated for their production capability of fumaric acid.…”