毒性检测系统中硝化菌的分离鉴定及其特性研究

Isolation,Identification and Characterization of Nitrobacteria for the Microbial Toxicity Testing System

对某鱼塘污泥进行选择性富集筛选,得到4株高效硝化菌F1,F4,Y2和Z1。采用Sherlock微生物鉴定系统(Sherlock MIS)对4株菌进行全细胞脂肪酸成分分析鉴定,并结合生理生化指标分析,初步确定菌株F1和F4属于红球菌属(Rhodococcus),Y2属于假单胞菌属(Pseudomonas),Z1属于微球菌属(Micrococcus)。硝化速率试验表明:菌株F1,F4,Y2和Z1的硝化速率分别达到3.51,3.43,3.46和3.52mg/(L.d);将4株菌等量混合组成复合菌,通过改变培养条件,进行综合条件下的L16(44)正交试验,在温度为35℃,pH为8.5,试液体积为20mL,接种量为25%时,复合菌NH4+-N的转化率最高达到70.02%。影响硝化反应效果的因素依次为试液体积>温度>pH>接种量。

Four strains of high-efficiency nitrobacteria, F1, F4, Y2 and Z1, were isolated from one fishpond’s silt. The Sherlock microbial identification system （MIS） was used to perform the whole cellular fatty acid composition analysis and identification for the four strains, combined with physiological and biochemistry indexes analysis. They were preliminarily identified as Rhodococcus （F1 and F4）, Pseudomonas （Y2） and Micrococcus （Z1）. The test of nitrifying rate showed that the nitrifying rate of F1, F4, Y2 and Z1 reached 3.51, 3.43, 3.46 and 3.52 mg/（L·d）, respectively. The four strains were mixed equally to form a bacterial complex and the orthogonal experiment under comprehensive cultivation conditions by changing cultivation conditions was carried out. The results showed that the highest NH4＋-N conversion rate of 70.02% was obtained at 35℃, pH 8.5, with 20 mL medium content and 25% inoculum size. Factors affecting nitrification effectiveness were in the order of medium content 〉 temperature 〉 pH 〉 inoculum size.