优化西瓜汁培养基提高细菌纤维素产量和性能

以木醋杆菌（Acetobacter xylinum）为发酵菌种，通过Plackett-Burman试验设计进行主效应因子的筛选，对西瓜汁培养基中无水乙醇和FeSO4的添加量进行优化，以细菌纤维产量为评价指标，获得最优的培养基为酵母膏12.5 g/L，蛋白胨10.0 g/L，磷酸二氢钾6.5 g/L，硫酸镁3.1 g/L，硫酸亚铁0.2 g/L，柠檬酸0.3 g/L，用西瓜汁培养基基料配制成1 000 mL，灭菌冷却后无菌地加入无水乙醇36 mL/L。在此最优条件下，细菌纤维素产量为6.39 g/L，分别是西瓜汁培养基基料及基础培养基发酵细菌纤维素产量的6.82倍、1.33倍。优化后的西瓜汁培养基发酵产细菌纤维素，其含水率、复水率、结晶度、热稳定性较优，分别比基础培养基提高了0.59%、3.27%、5.04%和6.03%。

Optimization of watermelon juice medium for improving bacterial cellulose yield and properties

With Acetobacter xylinum as fermentation strain, by Plackett-Burman design, the main effect factors were screened and the ethanol and FeSO4 addition in watermelon juice medium were optimized. With bacterial cellulose (BC) yield as evaluation indexes, the optimum medium was obtained as followed: yeast extract 12.5 g/L, peptone 10.0 g/L, KH2PO4 6.5 g/L, MgSO4 3.1 g/L, FeSO4 0.2 g/L, citric acid 0.3 g/L and watermelon juice 1 000 ml, after sterilization and cooling, adding ethanol 36 ml/L. Under the optimum condition, BC yield was 6.39 g/L, which was 6.82 and 1.33 times of watermelon juice medium base material and basic medium, the moisture content, rehydration rate, crystallinity and thermostability of bacterial cellulose fermented by watermelon juice medium optimized were increased by 0.59%, 3.27%, 5.04% and 6.03% of basic medium, respectively.