Production of cellulose from sugarcane molasses using Gluconacetobacter intermedius SNT-1: optimization & characterization

Abstract

Cellulose production by Gluconacetobacter intermedius SNT-1 under static condition was compared using various carbon sources. The trend observed was: HS-glucose > HS-glucose + sucrose + fructose > HS-fructose > HS-sucrose. Molasses, an industrial byproduct also served as a feedstock for cellulose production. Cellulose yield of 12.6 g L−1 was obtained from 45.8 g L−1 of diluted (1:4) molasses after H2SO4-heat pre-treatment. Cellulose yields were comparable using corn-steep liquor or yeast extract as the nitrogen sources along with heat pretreated molasses. Cellulose production was decreased by 30% in the absence of polypeptone. The number of viable cells entrapped within bacterial cellulose mat was much higher in comparison to that present in the spent medium. Cellulose immobilized cells may be protected against toxicity of components present in molasses. Bacterial cellulose produced from pretreated molasses contained mixture of cellulose I and cellulose II types, was predominantly in Iα (∼60%) form, had high tensile strength. This study demonstrates the suitability of using molasses from sugar industries as cheap carbon source for production of bacterial cellulose, with characteristics similar to those obtained using expensive carbon sources such as glucose or fructose. Huge amount of molasses is produced worldwide annually and therefore it is a readily available resource for cellulose production. Cellulose produced by bacteria using molasses is relatively pure which does not require extensive chemical treatments as in Kraft pulping or bleaching. Bacterial production of cellulose causes lower impact on environment in terms of pollution load and energy consumption.