双细胞体系木糖协同发酵产氢特性研究

Hydrogen production from xylose by synergetic fermentation in bi-cell system

采用自主筛选的两株蜡样芽胞杆菌(A1)和短波单胞菌属(B1),构建人工双细胞体系,重点研究了该双细胞体系利用木糖协同发酵产氢的能力,实验结果表明:单一的A1、B1菌种均能有效利用木糖产氢,而两株菌形成的双细胞体系显示出更高的产氢效率,以及更加充分的底物利用率;发酵产氢过程属于丁酸型发酵。人工双细胞体系混合培养的产氢得率达到1 mol木糖产生1.33 mol氢气,与A1、B1单菌体系木糖发酵产氢相比,产氢得率分别提高了10.7%与32.7%,其原因可能是两菌种互相提供营养来源,也可能是通过利用对方的代谢产物或中间体解除了降解物造成的抑制。说明以木糖作为底物时,人工双细胞体系能有效提升产氢速率,增加氢气产量,缩短发酵周期,具有较大的应用潜力。

An artificial bi-cell system has been constructed using Bacillus cereus（ A1） and Brevibacterium sp.（ B1）. The synergistic fermentation of xylose to give hydrogen has been studied in this artificial bi-cell system. The experimental results showed that whereas the single A1 and B1 strains can effectively produce hydrogen with xylose as substrate,the artificial bi-cell system showed higher hydrogen yields and better substrate utilization. The main pathway of hydrogen production was shown to involve butyric acid fermentation. The yield of hydrogen production in the artificial bi-cell system was 1. 33 mol H2/mol xylose. This is,respectively,10. 7% and 32. 7% larger than the yields obtained by fermentation with the single A1 and B1 strains. The reason for the higher yield may be that the two strains provide nutrients for each other and use each other＇s metabolites or intermediates to mitigate the possible inhibition caused by by-products. The results show that the artificial bi-cell system has great potential for application in fermentation with xylose as substrate,since it can increase the hydrogen yield and the rate of hydrogen production,and thus shorten the fermentation cycle.