• 关键词：芘  分枝杆菌  筛选  鉴定  降解

• 基金项目：国家重点基础研究发展规划(973)项目(No.2002CB410809)

• 贾宝亮
• 1. 中国农业大学, 生物学院微生物与免疫学系, 北京 100094; 2. 中国农业科学院, 农业资源与农业区划研究所, 北京 100081

• 范丙全
• 中国农业科学院, 农业资源与农业区划研究所, 北京 100081

• 隋新华
• 中国农业大学, 生物学院微生物与免疫学系, 北京 100094

• 龚明波
• 中国农业科学院, 农业资源与农业区划研究所, 北京 100081

• 摘要：为获得芘降解细菌,从中国南方地区采集了受PAHs严重污染的土壤与污泥样品.利用平板升华法,分离到2个菌株W52和W74.经形态观察、生理生化试验和16SrDNA的序列分析,2个菌株被鉴定为分枝杆菌属(Mycobacterium sp.).在含芘膜的固体平板上培养,W52和W74在23d中降解芘分别达到13.2μg和11.8μg.在含芘50mg·mL^-1和100mg·mL^-1的无机盐液体中培养,2d时W52的芘降解率达57.8%和20.5%,W74达19.2%和4.0%;随着培养时间的延长,芘降解率不断提高;在第10d时W52的芘降解率分别达到96.3%和82.3%,W74达83.8%和64.5%.在固体和液体条件下降解芘的结果表明,W52降解芘的能力强于W74.鉴于W52和W74末端双加氧化酶中编码α大亚基的nidA基因存在明显差异,推断二者降解芘的能力不同与它们的末端双加氧酶有关.

• Abstract：To obtain pyrene-degrading bacteria,soil and sludge samples were collected from severely PAHs-contaminated sites in South China.Strains W52 and W74 were isolated by agar plate subliming method.The two strains were identified as Mycobacterium sp.based on morphological observations,physiological test and 16SrDNAsequence analysis.When incubated on solid plates containing a thin pyrene film,W52 and W74 degraded 13.2 μg and 11.8 μg pyrene,respectively,in 23 days.When incubated in a liquid mineral salt medium containing 50 mg·L^-1 and 100 mg·L^-1 pyrene,W52 degraded 57.8% and 20.5% of the pyrene in 2 days;while W74 degraded 19.2% and 4.0%.Pyrene-degradation rates increased with incubation time.On the 10th day,W52 pyrene-degrading rates reached 96.3% and 82.3% respectively,while W74 reached 83.8% and 64.5%.In solid and liquid conditions,the results indicated that W52 degraded pyrene more effectively than W74.There were obvious differences between the nidA genes coding the large α subunit in the W52 and W74 terminal dioxygenases.We propose that the differences between the two strains abilities to degrade pyrene were related to their terminal dioxygenases.

• Key words：pyrene  Mycobacterium  isolation  identification  degradation

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