Abstract:In order to improve the yield of bacterial cellulose during kombucha fermentation, the response surface method was used to optimize the fermentation conditions, and the basic physicochemical properties of bacterial cellulose were measured. The optimal culture conditions for the production of BC by kombucha fermentation were determined by single factor test and response surface method as follows: tea concentration 0.83%(m/v), sucrose concentration 10.42%(m/v), liquid loading 70.22%, culture temperature 29.33 ℃. The experimental results showed that the actual yield of bacterial cellulose was 4.21 g/L under this condition, which was 60.08% higher than that before optimization (tea concentration 0.8%, sucrose concentration 6%, liquid loading 60%, culture temperature 30 ℃, yield 2.63 g/L). The determination of the physical and chemical properties of kombucha bacteria cellulose was determined, indicating that the quality fraction of coarse gluten, coarse starch, dietary fiber and gray score was 3.01%. Scanning electron microscopy (SEM) showed that the bacterial cellulose had an ultranetwork structure and the fiber diameter was nanometer. The tensile test showed that the cellulose strength of kombucha was about 2.28 MPa. The crystallinity of bacterial cellulose was 81.30% by X-ray diffraction. Response surface optimization method was used to improve the yield of kombucha fiber effectively.