Isolation And Identification Of A Strain Of Nitrifying Bacterium And Its Application On The Water

Water is the most critical resource of human production and life, but water resources devastated with nitrogen pollution increasing and Anabaena water bloom outbreaking. So the problem of removing nitrogen in water and controlling Anabaena water bloom must be solved. Nitrifying bacteria can effectively use excess nitrogen reduce to N2and release N2to the air by nitrification which is the main way of nitrogen removal. At the same time, exploring the effect of nitrifying bacteria to Anabaena also have a positive significance in the control of algal blooms.The high efficient nitrification process depends on screening of efficient nitrifying bacteria which can performance nitrification efficiently. Denitrifying bacteria was isolated from xinyang Henan Province. Through gram staining and aerobic type the bacteria is facultative anaerobic G" bacteria and according the sequencing of16S rDNA the bacteria is Delftia, and is a strain of typical bacteria have nitrification function. Researched the optimum growth temperature, pH, and the optimum nitrification temperature, pH of Delftia. The results showed that at a temperature of25℃, pH within the range of from6.5to7.0, Delftia has the highest growth rate and removal efficiency.Nitrifying bacteria used in the treatment of nitrate wastewater, by measuring the changes of nitrate and COD in water to research the purification of nitrifying bacteria to the water. The results showed that the nitrifying bacteria have an significantly effect on the nitrate wastewater, it provided a theoretical basis for water nitrification.Anabaena was purchased from Institute of hydrobiology by through enrichment, Under laboratory conditions, different concentrations of Delftia were added into the culture medium of Anabaena. By measuring the biomass of Delftia and Anabaena in the system of co-culture, it indicated that the growth of Anabaena was inhibited significantly by the nitrifying bacteria Delftia. Till the end of the experiment, a large number of Anabaena cells split and died. At the same time, researched the change of Anabaena photosynthetic system and antioxidant system infected by Delftia through surveying the six indicators of cells as follows:the concentration of Chlorophyll a, Fv/Fm value, the rate of photosynthetic oxygen evolution, CAT activity, POD activity, SOD activity. The results showed that the treated Anabaena photosynthetic system by a significant inhibition and the antioxidant enzyme activity was excited. Such as the concentration of Chlorophyll a, Fv/Fm value, the rate of photosynthetic oxygen evolution reduced significantly, the CAT activity, POD activity, SOD activity increased significantly in the beginning of the experimental, but remains at a downward trend with time passed. And the highest concentration of nitrifying bacteria caused the strongest destruction of the Anabaena photosynthetic system and antioxidant system. These results suggested nitrifying bacteria have an obvious inhibited effect on Anabaena cells. It provided a theoretical reference for the control of water blooms which Anabaena was the dominant algal group.Use of nitrifying bacteria and compound bacterium to deal with pharmaceutical wastewater, who has high number of COD. Through survey the experimental type wastewater, TN declining92.5%, CODr declining79.5%, chroma declining74.5%...