自生物絮团养殖池分离具有亚硝酸盐去除功能的细菌及其鉴定和特性

The Isolation, Identification and Analysis of a Nitrogen-Removing Bacterium Strain From Shrimp Farming Pond Using Bio- Floc Technology

关键词:  亚硝酸盐  去除  盐单胞菌  生物絮团

Key words:  Nitrite  Removal  Halomonas sp.  Bio-floc

摘要:

从凡纳滨对虾生物絮团养殖池排水渠中分离出一株对亚硝酸盐具有高效去除能力的菌株(201107290102)，16S rRNA序列分析结果显示，该菌株与美丽盐单胞菌(Halomonas venusta)的相似度高达99%，初步鉴定为美丽盐单胞菌。其去除亚硝酸盐最适条件为碳氮比(C/N)=15、温度37℃、初始pH 10.0、盐度40，最高去除率达91.7%。研究结果表明，该菌株能高效利用亚硝酸盐，可改良生物絮团养殖环境。

Abstract:

In a high density farming pond, the concentration of nitrite is often much higher than standard due to the excessive release of waste from feeding, breeding, and water pollutions. High nitrite is a prominent harmful factor in aquaculture. It can facilitate the growth of pathogenic bacteria, increase the stress for fishes and shrimp, render them prone to bacterial infection, and consequently lead to disease breakout. Nitrogen-removing has been widely recognized as an effective method to degrade nitrite in the water which comes from food residual and feces. An efficient nitrogen-removing bacterium strain, 201107290102, was isolated from the bio-floc in a shrimp farming pond. It was preliminarily identified as Halomonas venusta because 16S rRNA sequence analysis revealed that it shared 99% similarity in sequence with H. venusta. We next studied factors that determined the nitrogen-removing efficiency of this strain, including C/N ratio, temperature, initial pH and salinity. The optimal conditions were: C/N ratio 15, temperature 37℃, salinity 40, initial pH 10.0. Under the optimal conditions, the nitrogen-removing efficiency could be up to 91.7%. These results suggested that the strain 201107290102 could effectively degrade the nitrite. Our study provided a new tool for improving the bio-floc in shrimp culture.