不同有机碳与无机氨氮比(C／N)下自养硝化生物膜上微生物菌群的变化

The community structure changes of autotrophic nitrifying biofilms analyzed different C/N

通过变性梯度凝胶电泳技术(DGGE)研究随有机碳与无机氨氮比(C/N)升高,自养硝化膜上微生物菌群结构的变化.实验结果表明随C/N升高,微生物菌群从以硝化细菌为主导到以反硝化细菌为主导,硝化过程也由仅硝化到同时硝化反硝化.主要的硝化菌是Nitro-somonas europaea和Nitrobactersp.,主要的反硝化菌是Pseudomonassp.,Acidovoraxsp.和Comamonassp..在高C/N时,尽管反硝化菌占多数,但硝化菌并没有消失,而是与反硝化菌同存.

The process of nitrification is influenced by many environmental factors such as organic loading. In the presence of organic substrates nitrifying bacteria are usually outcompeted by heterotrophic bacteria. The effect of organic carbon on the community dynamics of nitrifying biofilms in batch experiments was investigated by denaturing gradient gel electrophoresis（DGGE）analysis. The result showed the dominant populations shifted from nitrifying bacteria to denitrifying bacteria with increase of C/N ratios. The dominant nitrifying bacteria were Nitrosornonas europaea and Nitrobacter sp. and the dominant denitrifying bacteria were Pseudomonas sp., Acidovorax sp. and Comamonas sp. Although at high C/N ratios the denitrifying bacteria were the dominant populations, nitrifying bacteria can simultaneously grow with them.