2株氨氮去除菌的分离鉴定及去除率影响因素分析

Screening and identification of two bacteria strains degrading ammonia-nitrogen and factors of degradation ammonia analysis

为了获得养殖池塘中高效去除氨氮的菌株,本研究采用富集培养分离的方法从虾贝混养池中筛选得到2株氨氮去除能力较高的菌株,编号分别为9A-7和9A-19。分子生物学及生理生化鉴定结果一致表明,菌株9A-7为非典型弧菌,菌株9A-19为魔鬼弧菌。分析2菌株不同生长时期的氨氮去除率,结果显示,氨氮去除与菌株的生长均显著相关,菌株9A-7生长量与氨氮去除率之间的相关系数为0.916,菌株9A-19生长量与氨氮去除率之间的相关系数为0.938。条件优化研究结果表明,培养液盐度、p H和培养温度对2菌株去除氨的效率均存在显著影响,其中盐度对2菌株氨氮去除率的影响相似,2菌株去除氨氮的理想盐度均为30,但低p H和高温对菌株9A-7的去除能力影响较小,高p H对菌株9A-19去除能力影响较小。当氨氮浓度为50 mg/L,在温度25℃、盐度30、p H7.5条件下培养,培养24 h的菌株9A-7和菌株9A-19除氨率分别高达74.67%和90.67%。结果表明,这2株筛选菌可作为氨氮去除的优良菌株。

In order to screen microorganisms of degrading ammonia-nitrogen in culture pond,the strain 9A-7and 9A-19 were isolated from the shrimp-shellfish co-culture pond water of Rizhao by degrading ammonianitrogen via enrichment culture. The results of molecular biological,physiological and biochemical identification consistently showed that the strain of 9A-7 is Vibrio atypicus and the strain of 9A-19 is Vibrio diabolicus. The results showed that the ammonia degradation ability was related to the growth of the two isolated strains,whose correlation coefficient between the isolated strain cell density and ammonia removal rate is 0. 916（ 9A-7） and 0. 938（ 9A-19）,respectively. The ability of degrading ammonia-nitrogen was significantly affected by salinity and p H of the culture solution and culture temperature,and the effect of salinity on ammonia removing rate of two strains was similar and the optimal salinity of both isolated strains was 30,however,the temperature has a less effect on the ammonia reduction rate of the strain 9A-7 than the strain 9A-19,and the weak alkalinity has more remarkable effect on that of the strain 9A-7 than the strain9A-19. At salinity 30,p H 7. 5,temperature 25 ℃,the ammonia reduction rate of the strains 9A-7 and 9A-19 was 90. 67%,and 74. 67%,respectively. The present results showed that the two isolated bacteria strains are ideal strains for removing ammonia of the culture water.