Doctoral Dissertations
Date of Award
8-2021
Degree Type
Dissertation
Degree Name
Doctor of Philosophy
Major
Environmental Engineering
Major Professor
Frank E. Löffler
Committee Members
Shawn R. Campagna, Qiang He, Jie Zhuang
Abstract
Fluorinated organics have been developed and produced for various applications in the industrial, military, medical and agrochemical fields; they are now emerging as persistent organic pollutants with demonstrated adverse health impacts on mammals, including humans. The high bond dissociation energy of C-F bond hinders microbial degradation and defluorination. The present work demonstrates Pseudomonas sp. strain 273 can utilize the 1-fluoroalkanes (C7 to C10 and C14) and 1,10-difluorodecane (DFD) as the sole carbon source in the presence of oxygen. In this study, fluorine mass balance analysis determined that the majority (> 90%) of the fluorine from the fluoroalkanes could be recovered as inorganic fluoride. Short-chain fluorinated fatty acids were detected as the degradation products in β-oxidation. Notably, metabolome analysis indicated that a meager portion of fluorinated intermediates (e.g., short-chain fluorinated fatty acids) could be channeled into anabolism in producing long-chain fluorinated fatty acids and fluorinated glycerophospholipids. In the cells of strain 273 grown with DFD, more than 90% of the glycerophospholipids were fluorinated. The covalent incorporation of fluorine into anabolic products was unraveled as a novel sink for fluorine, potentially and significantly impacting the fate and transport behavior of fluorinated organics in the environment. This study proposes a detailed fluoroalkane metabolism pathway and identifies defluorinating enzymes in strain 273 based on the collective metabolomic, genomic, and transcriptomic evidence. Two enzyme systems containing alkane 1-monooxygenase (Gene ID: 2814128504) and (S)-2-haloacid dehalogenase (2814128232), respectively, were upregulated in cells grown with DFD, which might be associated with defluorination of the DFD. The investigation of the fluoroalkanes metabolism in strain 273 using multi-omics approaches advances the understanding of fluorinated organics’ metabolic behavior in both catabolic and anabolic directions and can assist in the development of biodegradation, biosynthesis, and remediation strategies for fluorinated organics.
Recommended Citation
Xie, Yongchao, "Metabolomics, genomics and transcriptomics unravel fluoroalkane metabolism in Pseudomonas sp. strain 273.. " PhD diss., University of Tennessee, 2021.
https://trace.tennessee.edu/utk_graddiss/6545