【摘要】 对一株经紫外诱变手段筛选得到的细菌纤维素高产菌株木醋杆菌C544进行发酵条件和培养基成分研究,确定其产纤维素适宜温度范围为25℃￣31℃,30℃时纤维素产量最高;适宜的初始pH值范围为5.5￣7.0,在pH6.0时纤维素产量最高。优化出的培养基配方为:葡萄糖5.0%(w/v)、大豆蛋白胨0.9%(w/v)、Na2HPO4·12H2O0.8%(w/v)及柠檬酸0.5%(w/v),在最佳发酵条件下纤维素最大产量可达7.79g/L,是优化前产量的3.52倍。另研究了甘露醇对此菌株产细菌纤维素的影响,发现当基础培养基中加入10%(w/v)甘露醇作为碳源时,发酵终点的pH值为4.50,对纤维素的合成有利,纤维素产量达到9.33g/L,是优化前产量的4.22倍。更多还原

【Abstract】 A high-producing bacterial cellulose mutant strain Acetobacter xylinum C544 was obtained by ultraviolet mutagenesis. The optimum fermentation conditions and medium composition for the production of cellulose by A. xylinum C544 were investigated. The strain was able to produce cellulose at 25 ℃-31 ℃ with a maximum at 30 ℃. Cellulose production occurred at pH 5.5-7.0 with a maximum at pH 6.0. The improved medium composition was 5 % (w/v) glucose, 0.9 % (w/v) soybean peptone , 0.8 % (w/v) Na2HPO4·12H2O and 0.5 %(w/v) citric acid. Under optimum fermentation conditions, cellulose maximum production was 7.79 g/L, which was 3.52-fold higher than the yield before optimization. The effect of mannitol on cellulose production by A. xylinum C544 was investigated. In standard medium containing 10 %(w/v) mannitol, the terminal pH value was 4.50 and cellulose production was 9.33 g/L, which was 4.22- fold higher than the yield before optimization.更多还原