title: Changes in the microbial community during repeated anaerobic microbial dechlorination of pentachlorophenol.
abstract: Pentachlorophenol (PCP) has been widely used as a pesticide in paddy fields and has imposed negative ecological effect on agricultural soil systems, which are in typically anaerobic conditions. In this study, we investigated the effect of repeated additions of PCP to paddy soil on the microbial communities under anoxic conditions. Acetate was added as the carbon source to induce and accelerate cycles of the PCP degradation. A maximum degradation rate occurred at the 11th cycle, which completely transformed 32.3 μM (8.6 mg L-1) PCP in 5 days. Illumina high throughput sequencing of 16S rRNA gene was used to profile the diversity and abundance of microbial communities at each interval and the results showed that the phyla of Bacteroidates, Firmicutes, Proteobacteria, and Euryarchaeota had a dominant presence in the PCP-dechlorinating cultures. Methanosarcina, Syntrophobotulus, Anaeromusa, Zoogloea, Treponema, W22 (family of Cloacamonaceae), and unclassified Cloacamonales were found to be the dominant genera during PCP dechlorination with acetate. The microbial community structure became relatively stable as cycles increased. Treponema, W22, and unclassified Cloacamonales were firstly observed to be associated with PCP dechlorination in the present study. Methanosarcina that have been isolated or identified in PCP dechlorination cultures previously was apparently enriched in the PCP dechlorination cultures. Additionally, the iron-cycling bacteria Syntrophobotulus, Anaeromusa, and Zoogloea were enriched in the PCP dechlorination cultures indicated they were likely to play an important role in PCP dechlorination. These findings increase our understanding for the microbial and geochemical interactions inherent in the transformation of organic contaminants from iron rich soil, and further extend our knowledge of the PCP-transforming microbial communities in anaerobic soil conditions.
authors.affiliation: Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangzhou, 510650, People's Republic of China.|State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Tong
authors.affiliation: Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangzhou, 510650, People's Republic of China.
authors.forename: Manjia
authors.initials: M
authors.lastname: Chen
authors.affiliation: Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangzhou, 510650, People's Republic of China.
authors.forename: Fangbai
authors.initials: F
authors.lastname: Li
authors.affiliation: State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, People's Republic of China. liuchengshuai@vip.gyig.ac.cn.
authors.forename: Chengshuai
authors.initials: C
authors.lastname: Liu
authors.affiliation: Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangzhou, 510650, People's Republic of China.
authors.forename: Changzhong
authors.initials: C
authors.lastname: Liao
mesh_terms: D000085:Acetates / Q000378:metabolism; D000693:Anaerobiosis; D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D001673:Biodegradation, Environmental; D044822:Biodiversity; D054879:Halogenation; D010416:Pentachlorophenol / Q000378:metabolism*; D010802:Phylogeny; D025341:Principal Component Analysis; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D000085:Acetates; D012336:RNA, Ribosomal, 16S; D010416:Pentachlorophenol
keywords: Biodegradation; Dechlorination; Microbial community; Paddy soil; Pentachlorophenol