The Activity Of Removal Nitrogen About Heterotrophic Nitrification Bacteria And Their Functional Genes

With the rapid development of economy, the progress of science and technology, the industrial, agricultural, people and so on, all these lead the pollution seriously more than ever. Among these pollutants, the nitrogen compounds are increasing more and more, gradually become a key factor in environment pollutions. Nitrogen pollution in the water can cause eutrophication, aquatic animals died and water damaged. Nitrogen pollution in the air can damage the ozone layer, endangering human health. Nitrogen pollution in the soil can damage the crop and also the water quality. Anyway, the nitrogen pollution would seriously threaten the natural environment which we live in.Because the nitrogen pollution is increasing, many scholars do some research on the removal nitrogen technology, the current removal techniques include traditional nitrification-denitrification process, simultaneous nitrification and denitrification process, aerobic denitrification and anaerobic ammonia oxidation process and so on. The bacteria in these processes are very abundant, such as autotrophic ammonia oxidizing bacteria, heterotrophic nitrification bacteria, anaerobic ammonia oxidation, they play a key role in the removal nitrogen process. Especially the effect of heterotrophic nitrification bacteria which removal nitrogen is particularly significant, its nitrogen removal process is fast, efficient and inexpensive, with good usability, also have a good application to the actual project.In this paper, the strains separated from three kinds of habitat, including ordinary river, natural wetlands and farms with high ammonia wastewater, the results only from the pool of the Fu Min pig farm sewage isolated the nitrifying strains, and finally identified as Alcaligenes faecalis, is a kind of heterotrophic nitrification bacteria, indicating in the habitat of high strength ammonia wastewater, the heterotrophic nitrifying bacteria are enriching, so it's easy to be isolated. To research the ability of removal nitrogen about the strains, with ammonium chloride and sodium acetate as carbon and nitrogen source, testing the nitrogen index in the six days. The result is strain L14 and L90 have a good ability to removal the nitrogen and carbon. L14 degradated the ammonia by 97.72%, L90 degradated the ammonia by 95.66%, L14 and L90 on the COD degradation rate reached 91.05% and 86.63%. Intermediates including nitrite and nitrate accumulated rarely by experiments, showing strain can quickly denitrificate in the process, so their denitrification is perfect.In this paper, using the molecular biology techniques to detect the functional genes of Alcaligenes faecalis, the result found the nosZ gene which coding N2O reductase, nirK gene and nirS gene which coding nitrite reductase, also found there are not amo gene about primer amo-1F/amo-2R, nor gene were not detected, maybe the reason is that primer selection and PCR conditions is not suitable, it's needs further study.In summary, we can see that strain L14 and L90 have a good ability to removal the nitrogen and carbon, they are effectively for high C/N wastewater, and this have a good contributions to the actually application of projects; simultaneous detected of their functional genes, it's a broke through in the level of the molecular.