醋酸菌发酵产细菌纤维素的过程优化

In the production of bacterial cellulose (BC) by Gluconacetobacter hansenii via traditional Hestrin-Scharmm (HS) medium, there are still some problems that limit the production, such as low BC production and utilization rate of glucose. In this study, the results of BC production by fermentation of traditional HS medium and improved HS medium were first compared and the BC yield by improved HS medium was increased by 28% to 3.34 g/L. However, the fermentation waste still contained 41% residual sugar and 70% residual nitrogen. Afterwards, the primary fermentation waste was optimized and used for secondary fermentation. In consequence, 3.16 g/L of BC could be produced by adjusting the pH of fermentation waste to 5.9 and adding 2.5 g/L yeast extract and 1.8 g/L Na₂HPO₄, and the concentration of acetic acid was only half of that in primary fermentation. In conclusion, the yield of BC achieved 6.50 g/L, which was 2.5 times as much as before. Moreover, the utilization rate and conversion rate of glucose were increased from 56.74% to 88.02% and 22.86% to 36.87%, respectively.