Isolation And Identification Of Aerobic Denitrifying Bacteria And The Preliminary Research On Their Denitrification Performances

Nitrogen, a main water pollutant, can cause deterioration of water quality and water eutrophication. It has become a serious global environmental problem, and thus how to treat nitrogen pollution effectively is attracting more and more attentions. At present, biological treatment is recognized as the cost-effective and promising approach. However, the traditional biological nitrogen removal general consists of two completely separate process, aerobic autotrophic nitrification and anaerobic heterotrophic denitrification, which is comparatively complicated. With the appearance of aerobic denitrifying bacteria, nitrification and denitrification can occur in the same bioreactor not only to reduce the area but also to decrease the treatment cost. In the present study, some aerobic bacteria were isolated and identified from Guanyin Lake in Fujian Agriculture and Forestry University, and then their denitrification performances were investigated preliminarily, which could provide data and theoretical instruction for their application in treating nitrogen pollution.On one hand, the color reaction of BTB plate was used for the first screening, and then three strains with high performace of denitrification, named as HJH1、HJH2 and HJH3, respectively, were further sreened by shaking flasks. Afterwards, through mold mushroom spawn’s expanded raise, withdraws DNA, uses PCR to expand increases three strains 16SrDNA and measured the foreword analysis indicated, strain HJH1 and the Pseudomonas putida strain A5.516SrDNA sequence similarity is 94%, most has the possibility is the pseudomonad is, and has constructed the system cladogram with the MP law.At the same time, has constructed the system cladogram with the MP law, strain HJH2 and Klebsiella oxytoca strain IARI-NIAW2-1116SrDNA sequence similarity is 98%,most has the possibility is the Klebsiella oxytoca, strain HJH3 were identified as for Pantoea dispersa through the 16Sr DNA gene sequencing.On the other hand, the paper studied the HJH1 strain good oxygen denitrification characteristic, the tolerance nitrite nitrogen density as well as regarding this strain denitrification function most suitable pH, the temperature and the carbon source.The result indicated that, the three strains may remove the nitrite nitrogen, the nitrite nitrogen biggest tolerance density of strain HJH1 is effectively 70mg/L, the nitrite nitrogen biggest tolerance density of strain HJH2 is effectively 80mg/L, the nitrite nitrogen biggest tolerance density of strain HJH3 is effectively 500mg/L, strain HJH1,HJH2 grows most suitable pH is 7, strain HJH3 grows most suitable pH is 10; strain HJH1,HJH2 grows most suitable temperature is 30℃, strain HJH3 grows most suitable temperature is 37℃; strain HJH1,HJH2 grows most suitable carbon source is glycerine, strain HJH3 grows most suitable carbon source is sodium succinate;when the carbon source initial density is O.lmol/L.