Production of multienzymes consisting of alkaline amylase and cellulase by mixed alkalophilic culture and their potential use in the saccharification of sweet potato

Abstract

Multienzymes of alkaline amylase and cellulase were produced by a mixed culture system consisting of the respective producers of alkalophilic Bacillus sp. The mixed culture enabled the two kinds of alkalophiles to grow in the same culture. Compared with the respective pure cultures, the mixed culture exhibited a similar productivity of alkaline amylase, enhanced the secretion of alkaline cellulase from cell surface to the culture broth, and lowered the protease activity that might be harmful to the other enzymes in practical application. These findings show that the mixed alkalophilic culture is a useful method for the production of alkaline multienzymes. The crude multienzymes recovered by ethanol precipitation exhibited well-designable activities of amylase and cellulase, which simultaneously degraded both the starch and soluble cellulose.