title: Engineering artificial communities for enhanced FTOH degradation.
abstract: Fluorotelomer alcohols (FTOHs, [F(CF2)nCH2CH2OH]) are concerned environmental pollutants with perfluorinated carbon chains. FTOHs can be biotransformed; however, the extent, the pace of the defluorination, and types of metabolites produced vary depending on degradative microorganisms under different environment. In this study, we examined ways to increase the effectiveness of the FTOH defluorination process to less persistent major metabolites. Defined mixed cultures and bioaugmented microbial cultures were engineered to study their ability to biotransform 6:2 fluorotelomer alcohol [F(CF2)6CH2CH2OH]. The effects of carbon sources and the concentration of carbon sources were also examined. All experiments resulted in 5:2 sFTOH [F(CF2)5CH(OH)CH3] as the primary metabolite at the end point. The carbon sources resulted in different amounts of pathway utilization as well as overall changes in effectiveness. The best overall effectiveness was observed when cosubstrate carbon was kept at low concentrations. Pathway II was best utilized by the P. butanovora+P. fluorescens mixed culture, with lactate having a slight negative impact on pathway II utilization. Additional carbon to augmented activated sludge resulted in decreased 6:2 FTOH biotransformation by 60%. Enrichment cultures showed that shorter chain FTOHs are easier to degrade, with the n-octane enriched culture transforming 20% of 8:2 FTOH, 60% of 6:2 FTOH and 70% of 4:2 FTOH. The microbial communities of the enrichment cultures and the alkane hydroxylase gene were also examined to help understand FTOH biotransformation mechanisms.
authors: Zachry Department of Civil Engineering, Texas A&M University, College Station, TX 77843-3136, United States.
authors: Matthew
authors: M
authors: Lewis
authors: Zachry Department of Civil Engineering, Texas A&M University, College Station, TX 77843-3136, United States.
authors: Myung-Hee
authors: MH
authors: Kim
authors: 132 Shrewsbury Dr., Wilmington DE19810, United States.
authors: Ning
authors: N
authors: Wang
authors: Zachry Department of Civil Engineering, Texas A&M University, College Station, TX 77843-3136, United States. Electronic address: kchu@civil.tamu.edu.
authors: Kung-Hui
authors: KH
authors: Chu
mesh_terms: D001673:Biodegradation, Environmental; D001711:Biotransformation; D004785:Environmental Pollutants / Q000378:metabolism*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005466:Fluorocarbons / Q000378:metabolism*; D011549:Pseudomonas / Q000378:metabolism*; D020628:Thauera / Q000378:metabolism*
chemical_list: D004785:Environmental Pollutants; D005466:Fluorocarbons
keywords: Activated sludge; Bioaugmentation; FTOH; FTOH-degrading bacteria; alkB