Guo C L, Zhou H W, Wong Y S, Tam N F Y
Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong SAR, China.
Mar Pollut Bull. 2005;51(8-12):1054-61. doi: 10.1016/j.marpolbul.2005.02.012. Epub 2005 Mar 17.
Surface sediment samples were collected from seven mangrove swamps in Hong Kong SAR with different degrees of contamination. The total concentrations of 16 PAHs in these sediments ranged from 169.41 to 1058.37 ng g(-1) with the highest concentration found in Ma Wan and the lowest in Kei Ling Ha Lo Wai mangrove swamp. In each swamp, three bacterial consortia were enriched from sediments using phenanthrene (Phe) as the sole carbon and energy source, and individual bacterial colony showing Phe degradation was isolated and identified by 16S rDNA gene sequence. The consortia enriched from Sai Keng and Ho Chung sediments had highest ability to degrade mixed PAHs in liquid medium, with 90% Phe and Fla (fluoranthene) degraded in 7 days. On the other hand, Kei Ling Ha Lo Wai-enriched consortia degraded less than 40% Phe and Fla. Pyrene (Pyr) was hardly degraded by the consortia enriched from sediments. Bacterial isolates, namely Rhodococcus (HCCS), Sphingomonas (MWFG) and Paracoccus (SPNT) were capable to degrade mixed PAHs (Phe + Fla + Pyr). Their degradation percentages could be lower, comparable or even higher than their respective enriched consortia, depending on the consortium and the type of PAH compounds. These results suggest that PAH-degrading bacteria enriched from mangrove sediments, either as a mixed culture or as a single isolate could be used for PAHs bioremediation.
从香港特别行政区七个受不同程度污染的红树林沼泽采集了表层沉积物样本。这些沉积物中16种多环芳烃的总浓度在169.41至1058.37 ng g(-1)之间，其中马湾的浓度最高，企岭下老围红树林沼泽的浓度最低。在每个沼泽中，以菲（Phe）作为唯一碳源和能源，从沉积物中富集了三个细菌群落，并通过16S rDNA基因序列分离和鉴定了显示出菲降解能力的单个细菌菌落。从西贡和蚝涌沉积物中富集的群落对液体培养基中混合多环芳烃的降解能力最强，7天内90%的菲和荧蒽（Fla）被降解。另一方面，企岭下老围富集的群落降解的菲和荧蒽不到40%。沉积物中富集的群落几乎不能降解芘（Pyr）。细菌分离株，即红球菌（HCCS）、鞘氨醇单胞菌（MWFG）和副球菌（SPNT）能够降解混合多环芳烃（菲+荧蒽+芘）。根据群落和多环芳烃化合物的类型，它们的降解百分比可能低于、相当或甚至高于各自富集的群落。这些结果表明，从红树林沉积物中富集的多环芳烃降解细菌，无论是作为混合培养物还是单个分离株，都可用于多环芳烃的生物修复。
