| 摘要: |
| 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, 依次为pH 6.5> pH 7.5 > pH 8.0 > pH 6.0 > pH 5.5 > pH 5.0 > pH4.5 > pH 4.0。混合菌16S rRNA 基因的PCR 扩增产物经DGGE 分离, 电泳图谱表明, 不同起始pH 条件下混合菌群的优势菌相同, PCR 产物的测序结果与Clostridium sp.存在比较高相似度(98%)。Fe-氢酶基因扩增产物在DGGE 电泳图谱中存在一条特异条带, 其测定序列与Clostridium perfringens氢酶基因相似度为98%。不同起始pH 条件下混合菌群的产氢菌基本相同, 混合菌群产氢量之间的差异可能在于起始pH 对混合菌群Fe-氢酶基因活性的影响, 有待进一步研究确定。 |
| 关键词: 起始pH 产氢量 变性梯度凝胶电泳 16S rRNA 基因 Fe-氢酶基因 |
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| 基金项目:国家自然科学基金项目(40906074); 天津市科技支撑计划重点项目(07ZCGYSH03400); 天津市海洋资源与化学重点实验室开放基金项目(200912) |
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| The effect of initial pH on hydrogen production of microbial community from marine environment |
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| Abstract: |
| 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. |
| Key words: initial pH hydrogen production denaturing gradient gel electrophoresis (DGGE) 16S rRNA gene Fe-hydrogenase gene |
