1株甲苯降解真菌的筛选鉴定及其降解甲苯的特性

Screening,Identification and Bio-Degradation Characteristics of A Toluene Degradable Fungal Strain

从实验室保存的7株真菌筛选到1株能高效降解甲苯的菌株H1,基于形态特征、ITS序列系统学分析,将H1菌株鉴定为毛栓菌(Trametes hirsuta)。利用正交设计实验方法研究了温度、pH值、甲苯浓度和吐温80浓度对H1菌株降解甲苯的影响,研究得出该菌株降解甲苯的最适条件为30℃、pH 5.0、甲苯浓度300mg/L、吐温80浓度0.05%,在该条件下H1对甲苯的最大降解率为85.3%,降解率比未优化之前有了显著提高。比较了H1菌株在3种培养基产生漆酶的能力,H1在土豆葡萄糖培养基产酶能力最强,在第7天达到酶活高峰16 500 U/L。H1在甲苯为唯一碳源的培养基中,漆酶酶活最低,培养7 d时漆酶酶活为589 U/L。

A highly effective toluene degradable fungal strain H1 was screened from seven fungal strains preserved in the laboratory.It was identified as Trametes hirsuta according to its morphological characteristics and systematic analysis of ITS sequence.The effects on its conditions to degrade toluene,temperature,pH,concentration of toluene,and tween 80 concentration were studied by orthogonal designed experiment.The results showed that the optimum conditions were 30 ℃,pH 5.0,toluene 300 mg/L,tween 80 0.05%.Degradation rate on optimum conditions had been significantly improved as compared with that before optimization with 85.3% of toluene degraded.Comparison of laccase activity produced by Trametes hirsuta H1 cultured in three kinds of medium had found that,the highest one was in potato glucose medium and the capability of laccase activity was 16 500 U/L on 7th day’s culture.Laccase activity of H1 in the medium with toluene as the sole carbon source was the least and it was 589 U/L cultured by 7 days.