title: Impact of 6:2 fluorotelomer alcohol aerobic biotransformation on a sediment microbial community.
abstract: Sediment microbial communities are responsible for many chemical biotransformation processes in the aquatic environment and play a critical role in various ecosystems and biogeochemical cycling. However, the impact of polyfluoroalkyl substances on sediment microbial communities remains unclear. These substances are increasingly being used in consumer and industrial products to replace environmentally persistent perfluoroalkyl substances. In this study, we investigated the effects of low (5mg/L) and high (15mg/L) doses of 6:2 fluorotelomer alcohol [6:2 FTOH, F(CF2)6CH2CH2OH] on the structure of a sediment microbial community. 6:2 FTOH biotransformation was rapid in the sediment mixture with a half-life <3days, regardless of the initial doses. After 28days, major products produced in the high dose condition included 28mol% 5:2 sFTOH [F(CF2)5CH(OH)CH3], 9.6mol% 5:3 Acid [F(CF2)5CH2CH2COOH] and 11mol% PFHxA [F(CF2)5COOH], while 73mol% 5:2 sFTOH, 23mol% 5:3 Acid and 26mol% PFHxA were observed in the low dose condition. In the original (control) sediment without 6:2 FTOH dosing, Proteobacteria was the predominant microorganism (18%), followed by Chloroflexi (14%), Verrucomicrobia (13%), Firmicutes (3.4%), Bacterioidetes (2.4%), Actinobacteria (1.7%) and Planctomycetes (1.3%). The presence of 6:2 FTOH and the accumulation of transient transformation products in the sediment exerted selection pressure on the microbial taxonomic distribution and diversity. Our observations indicate that potential 6:2 FTOH degraders and tolerant strains, such as Dokdonella spp., Thauera spp., Albidovulum spp. and Caldanaerovirga spp., existed in the sediment mixture and began to dominate over time. This suggests that these genera might have higher tolerance towards elevated 6:2 FTOH and its transformation products. These findings on the characterization of sediment microbial community stability and dynamics will help predict changes in response to perfluoroalkyl and polyfluoroalkyl substances and also help identify robust microbial strains to degrade polyfluoroalkyl substances in the environment.
authors.affiliation: Laboratory for Earth Surface Processes, Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
authors.forename: Shu
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Earth-Life Science Institute, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8550, Japan.
authors.forename: Nancy
authors.initials: N
authors.lastname: Merino
authors.affiliation: 132 Shrewsbury Dr., Wilmington, DE 19810, USA. Electronic address: nwang.2@verizon.net.
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. Electronic address: tingruan@rcees.ac.cn.
authors.forename: Ting
authors.initials: T
authors.lastname: Ruan
authors.affiliation: Laboratory for Earth Surface Processes, Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China. Electronic address: luxx@urban.pku.edu.cn.
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Lu
mesh_terms: D001419:Bacteria / Q000145:classification / Q000378:metabolism*; D001711:Biotransformation; D005466:Fluorocarbons; D019015:Geologic Sediments / Q000382:microbiology*; D006845:Hydrocarbons, Fluorinated / Q000737:chemistry*; D014871:Water Microbiology
chemical_list: D005466:Fluorocarbons; D006845:Hydrocarbons, Fluorinated; C033729:fluorotelomer alcohols
keywords: 16S rRNA gene amplicon sequencing; Microbial community analysis; Microcosms; Polyfluoroalkyl substances; Proteobacteria