响应面法优化木醋杆菌发酵酿酒丢糟水解液产细菌纤维素培养基及其产物性能

为提高木醋杆菌(Acetobacter xylinum)发酵酿酒丢糟水解液生产细菌纤维素(bacterial cellulose,BC)的产量,采用响应面法对发酵培养基进行了优化,同时比较了发酵产物BC的性能和结构。通过单因素及响应面试验结果确定木醋杆菌发酵酿酒丢糟水解液生产BC的最佳培养基配方为:蔗糖39.33 g、蛋白胨20.01 g、Mg SO4 0.91 g、柠檬酸钠3.45 g、黄嘌呤1.02 g、乙醇10 m L、酒糟水解液1 000 m L、p H 6.0。在此条件下BC的产量为6.27 g/L,较优化前(4.4 g/L)提高了42.5%。利用傅里叶红外光谱、X射线衍射、扫描电子显微镜对发酵产物BC的性能和结构进行了比较,结果表明,酒糟水解液发酵产物BC结构性能与基本培养基发酵产物BC的基本一致,说明酒糟水解液能够替代部分发酵原料发酵生产BC,且不影响BC性能。

Optimization of Culture Medium Based on Vinasse Hydrolysate for Acetobacter xylinum by Response Surface Methodology for Enhanced Production of Bacterial Cellulose and Properties of the Product

Response surface methodology was used to optimize the fermentation medium based on vinasse hydrolysate for
enhanced production of bacterial cellulose (BC). Meanwhile, the properties and structures of the BC were compared with
those obtained with the basic culture medium. According to the results of single factor experiments and response surface
analysis, the optimal medium components were determined as follows: saccharose 39.33 g, peptone 20.01 g, magnesium
sulfate 0.91 g, sodium citrate 3.45 g, xanthine 1.02 g, ethanol 10 mL, vinasse hydrolysate 1 000 mL and pH 6.0, yielding
6.27 g/L of BC, which was increased by 42.5% when compared with that before optimization (4.4 g/L). The properties and
structures of BC produced with vinasse hydrolysate were confirmed to be basically the same as those of BC produced with
the basic medium through Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and scanning electron
microscopy (SEM), suggesting that vinasse hydrolysate could be used as an alternative raw material for the fermentation of
BC without any influence on the properties of BC.