Production of Bacterial Cellulose by Acetobacter xylinum in Static and Agitated Culture

摘要

The production of bacterial cellulose by Acetobacter xylinum subsp. sucrofermentans in a medium containing sucrose, yeast extract, and mineral salts under static and agitated culture was evaluated. The maximum growth of A. xylinum yielded counts of 2.55 x 10~(10) CFU/ml at 46 h of fermentation in static culture and provided counts of 3.34 x 10~(10) CFU/ml at 45 h of fermentation in agitated culture. In static culture, the yield of cellulose produced increased up until 6 days of cultivation to a value of 1.2 g/l (dry basis). The cellulose yield for agitated culture harvested at 2 days of cultivation was 0.6 g/l (dry basis). Cellulose was produced in the form of a pellicle in static culture, while accumulation of small aggregates of bacterial cellulose was observed in agitated culture. The generation time of A. xylinum in static and agitated cultured was 3.3 and 2.1 h, respectively. The pH of the medium decreased as cultivation time increased in both experiments.