Isolation,identification and nitrogen removal characteristics of two nitrifying bacteria
In this study,the black odorous water in Shayang Taiping River domestic sewage outlet was taken as the research object to verify its nitrification efficiency and product types under different carbon sources such as lactose,starch,formic acid,glucose and NaHCO3,so as to obtain its dominant carbon source,and further isolate and purify single bacteria with efficient nitrification function.The results showed that the removal efficiency of nitrogen under different carbon sources was different.The removal rate of ammonia nitrogen on the fourth day was lactose>NaHCO3>glucose>formic acid>starch,and the removal rate of nitrite nitrogen was lactose≈glucose>starch>NaHCO3≈ formic acid.The nitrification products with different carbon sources were quite different.The nitrification activity and ammonia nitrogen removal rate were the highest when glucose was used as the carbon source,while the ammonia nitrogen removal rate of the medium with formic acid as the carbon source with small molecular weight and simple chemical structure was not as high as that with glucose as the carbon source.Two strains of nitrifying bacteria were screened after several rounds of subculture and enrichment culture.Their 16S rRNA genes were cloned to obtain their taxonomic status,and their morphology was observed to verify their functions.The 16S rRNA gene sequencing results showed that the two pure strains were Phytobacter sp.and Gibbsiella sp.,so they were named Phytobacter sp.R3 and Gibbsiella sp.R4,respectively,with glucose,lactose,lactose,and NaHCO3 as their sole carbon source for growth.The removal rates of ammonia nitrogen and nitrite nitrogen by these two strains were above 85%.The application results of strain R4 in high ammonia nitrogen landfill leachate showed that the removal rates of NH+4-N and TN in leachate reached 60.4%and 48.44%respectively within 15 days after adding strain R4,and there was no accumulation of nitrate nitrogen and nitrite nitrogen,indicating that strain R4 could be used as an alternative strain for treating high ammonia nitrogen wastewater.
万方数据
维普
