Influence of Sugars, Sugar Alcohols and Their Combinations on Environmentally Significant Cellulase Production Under Liquid State Fermentation

Abstract

To expand the range of soluble carbon sources for enzyme production by the microbial system, we investigated the ability of different sugars in cellulase production. Carbon sources play a vital role in cell metabolism and the synthesis of cellulase. Although the insoluble cellulosic materials are considered the most effective natural inducers for cellulase production by microorganisms in terms of both enzyme yield and productivity, their insolubility causes many problems and presents a major drawback that is partly responsible for the high cost of cellulase production. Mostly, the insolubility of sugar polymer leads to difficult and complex fermentation operations, including sterilization, cell biomass measurement, mixing and aeration of the fermentation broth, continuous feeding/sampling, and subsequent enzyme purification. Second, cellulase gets absorbed into the solid cellulose surface, leading to enzyme loss. The present paper gives a comparative view on the utility of pure sugars (lactose, CMC, sucrose, maltose, cellobiose, xylose, trehalose, arabinose) and sugar alcohols (sorbitol, mannitol) on cellulase production by various fungal strains. It also describes the blending effect of sugars as well as sugar alcohols on cellulase production by fungal strains.