不同添加剂对木醋杆菌发酵细菌纤维素的影响

细菌纤维素是一类由细菌合成的天然纳米高分子材料,近年来由于细菌纤维素的应用日益增多而备受关注,细菌纤维素产量的提升有利于工业化生产。笔者以木醋杆菌(Gluconacetobacter xylinum)NLQ127为对象菌株,在静态好氧培养条件下考察了添加有机酸、大分子物质及植物激素对细菌纤维素产量的影响。研究结果表明:柠檬酸对细菌纤维素产量具有一定促进作用,当柠檬酸质量浓度为1.0 g/L时,细菌纤维素产量最高达到3.35 g/L; 大分子添加剂羧甲基纤维素钠和荧光增白剂对细菌纤维素的产量具有明显促进作用,发酵7 d纤维素产量分别达4.26和4.12 g/L,增幅为27.16%和22.98%。添加植物激素脱落酸可导致细菌纤维素产量达到3.87 g/L,较对照提高15.52%。当同时添加1.0 g/L柠檬酸、4.14×10-2 g/L荧光增白剂和5.28×10-2 g/L脱落酸时,木醋杆菌NLQ127静态发酵14 d细菌纤维素产量达到6.95 g/L。结果表明木醋杆菌NLQ127发酵产量较高,对提高细菌纤维素产量具有较为重要的意义。
Bacterial cellulose(BC)is a kind of natural nano-polymer material synthesized by bacteria. In recent years, because of the widely application of bacterial cellulose, its production has attracted a great deal of attention. The research of improving bacterial cellulose concentration is beneficial to the industrial production. In this study, by using Gluconacetobacter xylinum NLQ127 as the original strain, the effects of organic acids, macromolecular substances and phytohormones on bacterial cellulose production were investigated under static culture condition. The results showed that the bacterial cellulose production was 0.99 g/L and 0.82 g/L respectively, when acetic acid and ethanol were added. In contrast, citric acid had a positive effect on bacterial cellulose production. When the concentration of citric acid was 1.0 g/L, the production of bacterial cellulose reached 3.35 g/L. Regarding to macromolecular additives, the addition of agar, sodium alginate, carboxymethyl cellulose, magnesium lignosulfonate and chitosan inhibited the production of bacterial cellulose in different degrees. Both sodium carboxymethyl cellulose and fluorescent brightener showed a significantly enhancement for the production of bacterial cellulose. The cellulose production reached 4.26 g/L and 4.12 g/L after 7 d fermentation, with an increase of 27.16% and 22.98%, respectively. Moreover, this study also found that phytohormone abscisic acid demonstrated an obvious stimulation on cellulose production. Addition of abscisic acid resulted 3.87 g/L bacterial cellulose, which increased 15.52% compared to that of the control. The production of cellulose decreased by 5.67% and 6.27% by gibberellic acid and zeatin, respectively, and indole-3-acetic acid had little effect. When 1.0 g/L citric acid, 4.14×10-2 g/L fluorescent brightener and 5.28×10-2 g/L abscisic acid were added to the medium at the same time, bacterial cellulose reached 6.95 g/L after 14 d fermentation by G. xylinum NLQ127. Compared with previous studies, the bacterial cellulose production obtained in this study is higher, which is valuable for