污染土壤中菲高效降解菌的筛选及其降解特性

Screening of Highly Efficient Degradation Bacterium of Phenanthrene in Soil and Its Degradation Characteristics

运用恒温培养法研究了菲在不同土壤中的降解动态,结果表明未灭菌土壤中菲半衰期仅5.1d,而灭菌土壤中半衰期为前者4倍,可见土壤微生物发挥了重要作用;从试验土壤中分离到一株菲高效降解菌,经16SrDNA鉴定为产碱杆菌;优势菌最高可以耐受500mgL-1左右的菲,降解菲的最适温度25℃和pH为7,土壤接种优势菌后有助于加快菲的降解;从该优势菌中提取的粗酶液米氏常数为50.30nmolml-1,最大降解速率为171.33nmolmg-1min-1。

Degradation dynamics of phenanthrene in different soils were studied by incubation method,and the results showed that the half-life of phenanthrene in the non-sterilized soil was 5.1d,while that in the sterilized soil was four times than the former,which showed that microorganism played an important role.The highly efficient degradation bacterium which could effectively degrade phenanthrene was isolated from experimental soil,and it was identified by 16S rDNA as Alcaligenes sp.The dominant bacteria could only degrade phenanthrene concentration until 500 mg L-1,and the optimum temperature and pH value were 25 ℃ and 7.After the inoculation of the dominant bacteria into the soil phenanthrene degradation was further augmented.The Michaelis-Mentn＇s constant and maximum rate of the crude enzyme extracted from the dominant bacterium were 50.30 nmol mL^-1 and 171.33 nmol mg^-1 min^-1.