一株[艹屈]高效降解菌的分离鉴定及其降解特性

以多环芳烃艹屈] (Chrysene)为选择培养基的碳源, 从焦化污泥中筛选出一株艹屈]的高效降解菌SQ-1, SQ-1可在以艹屈]为唯一碳源的无机盐培养基中生长, 经过电镜形态学观察、生理生化和16S rDNA序列分析, 并基于16S rDNA序列结果, 构建了该菌株的系统发育树。最终确定菌株SQ-1为木糖氧化无色杆菌(Achromobacter xylosoxidans)。又考察了艹屈]的初始浓度、投菌量、pH值对SQ-1菌株降解艹屈]效果的影响, 确定了最佳降解条件。结果表明, 该菌对水中艹屈]具有良好的降解特性, 在艹屈]浓度为40 mg/L、接种量10% (V/V)、pH 7.0~7.5、温度30°C条件下, 接种5 d后对艹屈]的降解效率达到80%以上。

Isolation and Identification of a Chrysene-degrading Strain and Its Degradation Characteristics

A predominant chrysene-degrading strain was isolated and screened from biological sludge sampled from a coking plant, which can use chrysene as sole carbon source for growth in the selective culture medium. The phylogenetic tree of the strain was produced on the basis of morphology observation by SEM, experimental results of physiology and biochemistry and analysis of 16S rDNA sequence. The strain was identified as Achromobacter xylosoxidans. The effect of initial concentration of chrysene solution, inoculating dose and pH on degradation efficiencies was investigated. The results indicate that the degrading characteristics of the strain is fine. The optimal degrading conditions are: initial concentration of chrysene solution 40 mg/L, inoculating dose (V/V) 10%, pH 7.0~7.5, respectively. Under the optimal conditions, the degrading efficiency can reach more than 80% after 5 days at 30°C.