微生物および生化学技術ジャーナル

概要

Improved Production of Bacterial Cellulose From Gluconacetobacter Persimmonis GH-2

Basavaraj. S. Hungund and S. G. Gupta

Bacterial cellulose produced by members of the genus Gluconacetobacter displays unique properties including high mechanical strength, high water holding ability, high crystallinity, and an ultra-fi ne and highly pure fi ber network structure. It has many potential applications in biomedical, biosensor, food, textile and other industries. A cellulose producing strain isolated from nata sample (a desert) was identifi ed as Gluconacetobacter persimmonis (GH-2) based on biochemical studies and 16S rDNA complete sequence analysis. The strain produced 5.14 g/L of cellulose in standard medium under stationary growth conditions. For effective production of cellulose from the strain, various carbon and nitrogen sources were investigated in fl ask cultures under stationary conditions of incubation. Among various carbon sources glucose, fructose, sucrose, mannitol and inositol were found to be suitable for growth and cellulose production. The strain utilized a wide range of organic nitrogen sources such as peptone, casein hydrolyzate, beef extract, and malt extract for growth and cellulose production. The optimum pH and temperature for BC production by the strain were observed to be 5.5 and 30oC respectively. The organism was also found to produce substantial amount of cellulose under aerated and agitated culture conditions. Batch fermentation for cellulose production using glucose as a carbon source by the strain was carried out in a laboratory-scale fermenter. The strain produced 6.71 g/L cellulose in the fermenter which was 30% higher than that of the yield under stationary conditions of growth.