Genomic and proteomic characterization of Gordonia sp. NB4-1Y in relation to 6 : 2 fluorotelomer sulfonate biodegradation

Abstract

Gordonia sp. strain NB4-1Y was isolated from vermicompost using bis-(3-pentafluorophenylpropyl)-sulfide as the sole added sulfur source and was found to have a broad capacity for metabolizing organosulfur compounds. NB4-1Y is closely related to G. desulfuricans and was found to metabolize 6 : 2 fluorotelomer sulfonate (6 : 2 FTS) to 5 : 3 fluorotelomer acid (5 : 3 acid) via 6 : 2 fluorotelomer acid (6 : 2 FTCA), 6 : 2 unsaturated fluorotelomer acid (6 : 2 FTUCA) and 5 : 3 unsaturated fluorotelomer acid (5 : 3 Uacid). Given that the molecular and biochemical basis for the microbial metabolism of poly- and per-fluorinated compounds has yet to be examined, we undertook to investigate 6 : 2 FTS metabolism in NB4-1Y. To this end, a whole-genome shotgun sequence was prepared and two-dimensional differential in-gel electrophoresis was used to compare proteomes of MgSO4- and 6 : 2 FTS-grown cells. Of the three putative alkanesulfonate monooxygenases, four nitrilotriacetate monooxygenases and one taurine dioxygenase located in the draft genome, two nitrilotriacetate monooxygenases were differentially expressed in the presence of 6 : 2 FTS. It is hypothesized that these two enzymes may be responsible for 6 : 2 FTS desulfonation. In addition, a differentially expressed putative double bond reductase may be involved in the reduction of 5 : 3 Uacid to 5 : 3 acid. Other proteins differentially expressed during 6 : 2 FTS metabolism included a sulfate ABC transporter ATP-binding protein and two alkyl hydroperoxide reductases. This work establishes a foundation for future studies on the molecular biology and biochemistry of poly- and per-fluorinated compound metabolism in bacteria.