Li Jibing, Zhang Dayi, Song Mengke, Jiang Longfei, Wang Yujie, Luo Chunling, Zhang Gan
Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.
University of Chinese Academy of Sciences, Beijing, 100039, China.
Biodegradation. 2017 Dec;28(5-6):423-436. doi: 10.1007/s10532-017-9806-9. Epub 2017 Sep 27.
The indigenous microorganisms responsible for degrading phenanthrene (PHE) in activated biosludge were identified using DNA-based stable isotope probing. Besides the well-known PHE degraders Burkholderia, Ralstonia, Sinobacteraceae and Arthrobacter, we for the first time linked the taxa Paraburkholderia and Kaistobacter with in situ PHE biodegradation. Analysis of PAH-RHD gene detected in the heavy DNA fraction of C-PHE treatment suggested the mechanisms of horizontal gene transfer or inter-species hybridisation in PAH-RHD gene spread within the microbial community. Additionally, three cultivable PHE degraders, Microbacterium sp. PHE-1, Rhodanobacter sp. PHE-2 and Rhodococcus sp. PHE-3, were isolated from the same activated biosludge. Among them, Rhodanobacter sp. PHE-2 is the first identified strain in its genus with PHE-degrading ability. However, the involvement of these strains in PHE degradation in situ was questionable, due to their limited enrichment in the heavy DNA fraction of C-PHE treatment and lack of PAH-RHD gene found in these isolates. Collectively, our findings provide a deeper understanding of the diversity and functions of indigenous microbes in PHE degradation.
利用基于DNA的稳定同位素探测技术，确定了活性生物污泥中负责降解菲（PHE）的本土微生物。除了众所周知的菲降解菌伯克霍尔德氏菌、罗尔斯通氏菌、中华根瘤菌科和节杆菌外，我们首次将类伯克霍尔德氏菌属和凯斯特氏菌属与原位菲生物降解联系起来。对在C-PHE处理的重DNA组分中检测到的多环芳烃-还原酶（PAH-RHD）基因的分析表明，PAH-RHD基因在微生物群落中传播存在水平基因转移或种间杂交机制。此外，从同一活性生物污泥中分离出三株可培养的菲降解菌，分别为微杆菌属PHE-1、红杆菌属PHE-2和红球菌属PHE-3。其中，红杆菌属PHE-2是其属内首个被鉴定出具有菲降解能力的菌株。然而，由于它们在C-PHE处理的重DNA组分中富集有限，且在这些分离物中未发现PAH-RHD基因，这些菌株在原位菲降解中的作用值得怀疑。总的来说，我们的研究结果为深入了解本土微生物在菲降解中的多样性和功能提供了依据。
