为评估棉纤维固定化酵母生产乙醇的可行性,首先对棉纤维表面基团进行化学修饰,以提高载体对酵母细胞的吸附能力。其次分析了固定化发酵的稳定性,并从细胞数量角度定量分析固定化发酵和游离发酵的差异性。结果表明,经过F6-2试剂处理后的载体吸附效果有明显提升,其吸附比例达到83.1%,比未处理的固定化载体提高了15.9%。采用修饰的载体进行固定化发酵表现出较好的稳定性,发酵6批的平均转化率和产率分别为96.77%和5.22 g/(L·h),相比游离发酵,分别提高3%和51.7%。固定化发酵体系中,发酵6批后总酵母数为4.86×108 CFU/mL,是游离发酵体系的2倍。结果表明,利用修饰的棉纤维进行固定化发酵具有明显的优势和应用可行性。
The feasibility of yeast immobilization on cotton fiber for ethanol production was evaluated. Firstly, the surface groups of cotton fibers were chemically modified to improve adhesion ability. Secondly, the stability of immobilized cell fermentation was analyzed, and quantitative differences between immobilized and free cell fermentation were analyzed. The results showed that the adhesion ability of the carriers (the adhesion ration: 83.1%) which were treated with F6-2 increased by 15.9%, comparing with that of the carriers without treatment. Furthermore, the immobilized cell fermentation with the treated carriers demonstrated better stability. Compared with the free cell fermentation, the average conversion rate (96.77%) and yield [5.22 g/(L·h)] of the six batches enhanced by 3% and 51.7% respectively. After six batches of the immobilized cell fermentation, the total number of yeast was 4.86×108 CFU/mL, which was twice of the free cell fermentation. The results showed that immobilized cell fermentation with the modified cotton fiber had obvious advantages and feasibility.
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