起始pH值对海洋混合菌群产氢量的影响

对采自天津潮间带的污泥进行热休克处理，厌氧条件下富集混合菌群进行产氢试验；设置起始pH从4．0到8．0（间隔0．5个单位），比较混合菌群在不同pH培养条件下产氢量；利用变性梯度凝胶电泳（DGGE）分析不同起始pH培养条件下的混合菌群组成。结果表明，在起始pH为7．0时，混合菌群产氢量最高。不同起始pH对产氢量的影响，依...

The effect of initial pH on hydrogen production of microbial community from marine environment

Sludge, collected from the intertidal zone of a bathing beach in Tianjin, was pretreated by the heat-shock method and enriched under anaerobic condition for hydrogen-production. Hydrogen production was investigated under various initial pHs , ranging from 4.0 to 8.0. The composition of microbial community under various initial pHs was analyzed by denaturing gradient gel electrophoresis (DGGE). The result showed that hydrogen production potential of the mixed culture was the highest at the optimal pH of 7.0. The effects of initial pHs on hydrogen production followed the order of pH 6.5> pH 7.5 > pH 8.0 > pH 6.0 > pH 5.5 > pH 5.0 > pH 4.5 > pH 4.0. The 16S rRNA gene was PCR amplified and analyzed by DGGE. The dominant bands obtained on DGGE of 16S rRNA gene were identical at various pH values. These bands were cloned and sequenced. NCBI blast indicated that the segment of 16S rRNA gene was identical to that of Clostridium sp.. There was only one band on DGGE of Fe-hydrogenase gene of Clostridium sp.. The result of sequence similarity searching with NCBI BLAST indicated that the segment of Fe-hydrogenase gene was 98% identical to that of Clostridium perfringens. There existed identical hydrogen-producing bacterium of the mixed culture under various pHs. Initial pH could affect hydrogen production of the mixed culture through its influence on Fe-hydrogenase activity. This hypothesis needs further confirmation.