以橘渣为原料间歇振荡法生产细菌纤维素

Study on bacterial cellulose production from citrus dregs by intermittent shaking culture

以筛选于腐败柑橘表面的细菌纤维素(bacterial cellulose,BC)高产菌——中间葡糖酸醋杆菌CIs26为发酵菌株,以间歇振荡法为培养方式,研究橘渣预处理工艺、碳源、氮源和增效因子等营养条件对BC产量的影响。优化后的工艺条件为:橘渣与水混合比例1∶6,添加0.3 g·L^(-1)果胶酶和0.1 g·L^(-1)纤维素酶,45℃酶解2 h。以滤液代替去离子水复配培养基,以蔗糖(70 g·L^(-1))为碳源、硫酸铵(3 g·L^(-1))为氮源、酵母粉(7 g·L^(-1))为生长因子、乳酸(1 g·L^(-1))与磷酸氢二钠(2 g·L^(-1))为增效因子,在此条件下,BC产量达10.26 g·L^(-1)。说明橘渣经适当预处理与复配后,能够作为CIs26菌株间歇振荡法生产BC的优良培养基。

In the present study,a bacterial cellulose( BC) high-yielding producer,Gluconacetobacter intermedius CIs26,screened from rotten citrus fruits,was utilized as fermentation strain. Effects of citrus dregs pretreatment,carbon source,nitrogen source,and growth factor on BC gel production by intermittent shaking culture were investigated. It was shown that the optimized conditions for pretreatment of citrus dregs were as follows: mixing ratio of citrus fruit dregs to water was 1∶ 6; the addition of pectinase and cellulase were 0. 3,0. 1 g·L^(-1),respectively; hydrolysis temperature was 45 ℃,and hydrolysis time was 2 h. The filtered hydrolysate of citrus dregs was used as the solvent of culture medium. The optimal conditions for BC production were as follows: sucrose 70 g·L^(-1),ammonium sulphate 3 g·L^(-1),yeast extract 7 g·L^(-1),lactic acid 1 g·L^(-1),and disodium phosphate 2 g·L^(-1). Under the above condition,BC yield reached 10. 26 g·L^(-1),suggesting that citrus dregs could be a good raw material for BC production of CIs26 by intermittent shaking culture.