生物絮团中异养亚硝化菌的分离鉴定及其特性

Isolation and identification of heterotrophic nitrosobacteria from bio-flocs and analysis of their characteristics

中文关键词: 生物絮团  异养亚硝化细菌  氨氮转化率  盐单胞菌

英文关键词: Bio-flocs  Nitrosobacteria  Ammonia transforming rate  Halomonas sp.

中文摘要:

      采用富集培养、分离纯化等微生物学手段，从对虾养殖池的生物絮团中筛选出两株对氨氮具有高转化率的菌株。16S rRNA测序及系统发育分析结果表明,两株菌均属于盐单胞菌属，菌株2011072708与食物盐单胞菌Halomonas alimentaria有99%的同源性，而菌株2011072709与胜利盐单胞菌H. shengliensis有100%的同源性。比较研究了两株菌在不同温度、盐度、pH、碳氮比条件下对氨氮的转化率，菌株2011072708在温度37 ℃、盐度30~40、pH 8、碳氮比28的条件下对氨氮的转化率最高；菌株2011072709在温度27~42 ℃、盐度40~50、pH 6、碳氮比21的条件下对氨氮的转化率最高。研究结果表明，胜利盐单胞菌(2011072709)对温度、盐度、pH、碳氮比等各方面的适应性优于食物盐单胞菌(2011072708)，更适合在生物絮团技术中得到应用。

英文摘要:

      Two strains of nitrosobacteria with high ammonia transformation rate were isolated by enrichment and selective culture from bio-flocs of shrimp culture ponds. Sequences of 16S rRNA indicated that both strains belonged to the genus Halomonas sp., while strain 2011072708 was identified as H. alimentaria with 99% similarity, and strain 2011072709 as H. shengliensis with 100% similarity. Ammonia transformation rates of the two strains were compared under different temperatures, salinities, pH, and C/N ratios. The ammonia transformation rate of strain 2011072708 reached the highest level at 37 ℃, 30~40, pH 8, and C/N ratio of 28, while that of strain 2011072709 reached the maximum at 27~42 ℃, 40~50, pH 6, and C/N ratio of 21. The present study showed high ammonia transformation rates in both nitrosobacteria strains isolated from bio-flocs. Strain H. shenliensis (2011072709) had better adaptability to temperature, salinity, pH, and C/N ratio than H. alimentaria (2011072708), and may be more suitable for application in bio-flocs technology.