Isolation Of Heterotrophic Nitrification Bacteria、Identification And Characteristics Of Pseudomonas Stutzeeri YZN-001

Eight strains of heterotrophic bacteria were isolated from pig manure effluent. StrainYZN-001 could remove nitrogen most rapidly in these 8 strains. It was rod-shaped, gram-negative, and identified as Pseudomonas stutzeri base on the biochemical tests and 16S rDNA sequencing analysis, and named Pseudomonas stutzeri sp. YZN-001.A group of silver carp larvaes which aged 15 days were select to test the security of the isolated strains, they were immersed into the bacteria suspension with the final concentration of 1×107cfu/mL. Compared the death of tested fishes to the control group, there were no difference, indicating the strains of probiotics were safe for the cultured silver carp.The effect of different culture conditions on ammonium removal of strain YZN-001 was estimated by single-factor experiments. Strain YZN-001 could degrade ammonium from 4℃to 37℃and after 14 d culture, its removal rate of ammonium couble be higher than 90%. The most optimal C/N and pH for nitrogen removal were 12 and 9. Nearly no nitrate and nitrite were detected during the process of nitrogen removal by strain YZN-001. Using potassium nitrate and sodium nitrite instead of ammonium sulfate as the nitrogen source to test the denitrification of strain YZN-001, the experiment indicate that its removing rate of nitrate and nitrite were 97.3% and 100%. By 24 h, To take the nitrogen balance,39.3% of the removal nitrogen was transformed into N2 and 39.8% of which was transformed into intracellular N.Nitrogen removal ability of strain YZN-001 was evaluated in the domestic sewage and aquaculture wastewater. It’s found that the growth and nitrogen removal ability of strain YZN-001 depended much on the quantity of small molecule carbon source, and nitrogen removal rate of strain YZN-001 in the domestic sewage and aquaculture wastewater were 83.10% and 61.38%.