The Research Of Fermentation Microbulbifer Hydrolyticus IRE-31 To Produce Cellulase

Cellulase is a kind of compound enzyme, which can catalyze hydrolysis of lignocellulose to monosaccharide or oligosaccharide. Cellulase has a wide range of applications in food, animal husbandry, textile and other industries. At present, cellulase becomes a research hotspot because of its capacity of providing reducing sugar for production of bioethanol. This study had focused on the production of cellulase under different carbon source by using a short growth cycle and environment adaptable strain——Microbulbifer hydrolyticus IRE-31. At the same time, industrial waste vinasse was used as raw materials. We got the lees hydrolysate by different extraction methods to study the effect of the lees hydrolysate as a leading carbon source on the bacterial metabolism enzyme production. The enzyme production ability of the original strain was low, which improved to 56 U/L by fermentation of strain RE-13 getting from a cycle of ultraviolet mutagenesis, increased 2.7 times.This experiment studied the influence of 16 different carbon sources on fermentation of RE-31 enzyme production. In separate carbon source fermentation experiments, the best induced effect of 252.41 U/L was found in xylan, followed by xylose and glucose with the enzyme activity at 206.42 U/L and 100.45 U/L, respectively; in the mixed fermentation experiments, when xylose and glucose was mixed by 4:1, enzyme production was as high as 450 U/L at 12h. Meanwhile, production of cellulase was found to be inhibited while lactose and fructose was exploited as carbon source. This study demonstrated that the hydrolysate of vinasse can be produced through high temperature extraction by the mixed acid including 1% hydrochloric acid and 1% phosphoric acid. After processing with adsorption, detoxification and enrichment, the amount of reducing sugar in hydrolysis was 358.02 mg/ml with little harmful by-products furfural remained. Xylose and glucose are the main group in the hydrolyzate, they are the same with the pure in the mixd fermentation which have the best result. So use this hydrolyzate as a follow-up experiment carbon hydrolyzate. Using the lees hydrolysate as substrate for enzyme production fermentation, the ability of bacterial enzyme production increased 1.5 times and increased to 86.64 U/L at 12 h.In summary, our experiment declared that induced strain RE-13 could exploit vinasse hydrolysate as fermentation substrate to produce cellullase. Mutant strain RE-13 used to shorten the original fermentation cycle. Lees hydrolyzate used as a carbon source, improve the effective utilization of industrial waste lees, reducing the cost of production of cellulase fermentation.