Abstract: In order to obtain high performance hydrogen-producing bacteria, two strains (H-1 and H-2) were screened from activated sludge which was pretreated by alkali. Biological identification showed that the two strains were of Enterobacter species. H-1 was Enterobacter cancerogeous HG6 2A species and H-2 had the closest relationship with Enterobacter homaechei83. Results showed that the best performance could be achieved from co-fermentation at the ratio of 1:1 (H-1:H-2). The corresponding fermentation time and hydrogen yield were 33h and 861mL/L, respectively. The defects of lower hydrogen yield by H-1 and longer fermentation time by H-2 were overcome by co-fermentation. The main volatile fatty acids (VFA) in the broth were acetate and butyrate, indicating that the fermentation of the two strains were both butyrate type. Due to the synergistic effect of the two strains, the accumulation rate of VFA reduced at the initial of fermentation. As a result, the stability of the system was enhanced.

Key words: hydrogenogen, 16S rDNA, hydrogen production, fermentation, synergistic effect

摘要： 为了获得高性能的产氢菌,从碱处理后活性污泥中分离纯化得到两株产氢菌(H-1和H-2),生物学鉴定表明两株菌均为Enterobacter种属,H-1菌为Enterobacter cancerogeous HG6 2A种属,而H-2与Enterobacter homaechei83的关系最亲近.发酵实验结果表明,将H-1和H-2菌液进行1:1混合时发酵性能最佳,对应的发酵时间和产氢量分别为33h和861mL/L,混合发酵克服了H-1菌单独发酵氢产量低和H-2菌发酵时间长的缺陷.发酵液中主要挥发性脂肪酸(VFA)为乙酸和丁酸,表明两株菌的发酵类型均为丁酸型发酵.由于两株菌的协同作用,混合发酵初期VFA的累积速率降低,提高了发酵体系的稳定性.

关键词: 产氢菌, 16S rDNA, 制氢, 发酵, 协同作用