耐盐好氧反硝化菌黏质沙雷氏菌HL4的分离鉴定及脱氮性能OA北大核心CHSSCDCSTPCD

[Objective]To isolate and identify an efficient salt tolerant aerobic denitrifying bacterial strain and strengthen the research of denitrization technology in seawater and brackish water culture.[Method]Using the in-situ sediment of Lateolabrax maculatus pond as screening objects,a strain HL4 with the best denitrification function was initially isolated by dilution coating method.The strain was identified by 16s rDNA sequencing and physiological and biochemical experiments.The optimal culture conditions and denitrifying performance were investigated by setting different carbon sources,carbon nitrogen mass ratio(mC/mN),pH,temperature,salinity and other conditions.The environmental safety of the strain was tested by challenge test(with healthy zebrafish,Danio rerio,as the test organism).[Result]The strain HL4 was identified as Serratia marcescens,named S.marcescens HL4.Using glucose or sodium succinate as carbon source,the strain HL4 had strong nitrogen removal ability at mC/mN=20,pH=6.0-7.0,and temperature 30℃,48 h TN removal rate was 81.83%-87.17%.The strain could grow in 0-30 salinity environment and had a certain nitrogen removal ability.The 72 h TN removal rate at 0-10 salinity was 68.76%-76.59%,and the 72 h TN removal rate at 20-30 salinity was 23.84%-53.94%.When the concentration of NH4+-N was 0-100 mg·L-1,the 72 h removal rate of NH4+-N was above 90%;when the concentration of NH4+-N was 500 mg·L-1,the 72 h removal rate of NH4+-N is as high as 73.52%.After 15 days in water containing 1×106 CFU·mL-1 strain HL4,the survival rate of healthy zebrafish was 100%.[Conclusion]Strain HL4 has high biosafety and environmental safety,and has potential application value in the treatment of high-concentration ammonium wastewater,brackish water and low-salinity aquaculture tail water.