title: Sulfur Metabolism Pathways inSulfobacillus acidophilusTPY, A Gram-Positive Moderate Thermoacidophile from a Hydrothermal Vent.
abstract: Sulfobacillus acidophilusTPY, isolated from a hydrothermal vent in the Pacific Ocean, is a moderately thermoacidophilic Gram-positive bacterium that can oxidize ferrous iron or sulfur compounds to obtain energy. In this study, comparative transcriptomic analyses ofS. acidophilusTPY were performed under different redox conditions. Based on these results, pathways involved in sulfur metabolism were proposed. Additional evidence was obtained by analyzing mRNA abundance of selected genes involved in the sulfur metabolism of sulfur oxygenase reductase (SOR)-overexpressedS. acidophilusTPY recombinant under different redox conditions. Comparative transcriptomic analyses ofS. acidophilusTPY cultured in the presence of ferrous sulfate (FeSO4) or elemental sulfur (S0) were employed to detect differentially transcribed genes and operons involved in sulfur metabolism. The mRNA abundances of genes involved in sulfur metabolism decreased in cultures containing elemental sulfur, as opposed to cultures in which FeSO4was present where an increase in the expression of sulfur metabolism genes, particularly sulfite reductase (SiR) involved in the dissimilatory sulfate reduction, was observed. SOR, whose mRNA abundance increased in S0culture, may play an important role in the initial sulfur oxidation. In order to confirm the pathways, SOR overexpression inS. acidophilusTPY and subsequent mRNA abundance analysis of sulfur metabolism-related genes were carried out. Conjugation-based transformation of pTrc99A derived plasmid from heterotrophicE. colito facultative autotrophicS. acidophilusTPY was developed in this study. Transconjugation betweenE. coliandS. acidophiluswas performed on modified solid 2:2 medium at pH 4.8 and 37°C for 72 h. The SOR-overexpressed recombinantS. acidophilusTPY-SOR had a [Formula: see text]-accumulation increase, higher oxidation/ reduction potentials (ORPs) and lower pH compared with the wild type strain in the late growth stage of S0culture condition. The transcript level ofsorgene in the recombinant strain increased in both S0and FeSO4culture conditions, which influenced the transcription of other genes in the proposed sulfur metabolism pathways. Overall, these results expand our understanding of sulfur metabolism within theSulfobacillusgenus and provide a successful gene-manipulation method.
authors.affiliation: Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, State Oceanic Administration Xiamen, China.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Guo
authors.affiliation: Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, State Oceanic AdministrationXiamen, China; Department of Bioengineering, School of Minerals Processing and Bioengineering, Central South UniversityChangsha, China.
authors.forename: Huijun
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, State Oceanic AdministrationXiamen, China; Department of Bioengineering, School of Minerals Processing and Bioengineering, Central South UniversityChangsha, China.
authors.forename: Wengen
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, State Oceanic Administration Xiamen, China.
authors.forename: Yuguang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Bioengineering, School of Minerals Processing and Bioengineering, Central South University Changsha, China.
authors.forename: Hongbo
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, State Oceanic AdministrationXiamen, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory forMarine Science and TechnologyQingdao, China.
authors.forename: Xinhua
authors.initials: X
authors.lastname: Chen
keywords: SOR; Sulfobacillus acidophilus TPY; moderate thermoacidophile; sulfur metabolism; transcriptomic analysis