Enhancement of bacterial cellulose production in Bacillus amyloliquefaciens

Recently, bacterial cellulose (BC) has become more commonly applied as a new nano-biological material within the food, paper manufacturing and pharmaceutical production industries. However, the current methods of BC production are not ideal because of their low productivity and large number of byproducts. To improve the yield of cellulose production in bacteria, various carbon and nitrogen sources for the fermentation conditions of BC by Bacillus amyloliquefaciens ZF-7 were investigated. The effects of D-glucose, yeast extract and ethanol concentration on BC production by strain ZF-7 were studied by single factor methods. Based on the above results, the effects of D-glucose, yeast extract and ethanol concentration on BC production were investigated by means of a five-level factor central composite design and response surface methodology. D-glucose and yeast extract concentration were found to have a significant linear effect on BC production, and the interaction between D-glucose concentration and yeast extract concentration also had significant influence on BC production. The obtained optimum culture medium contained 56.1 g•L⁻¹ of D-glucose, 9.9 g•L⁻¹ of yeast extract and 17.2 mL•L⁻¹ ethanol. Under these conditions, the BC yield of B. amyloliquefaciens ZF-7 reached 7.88 g/l, which represents a 35.4% increase compared to the initial yield before the optimization.