Abstract: 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.

Key words: bacterial cellulose, producing technology, citrus dregs