title: Comparative genome analysis reveals metabolic versatility and environmental adaptations of Sulfobacillus thermosulfidooxidans strain ST.
abstract: The genus Sulfobacillus is a cohort of mildly thermophilic or thermotolerant acidophiles within the phylum Firmicutes and requires extremely acidic environments and hypersalinity for optimal growth. However, our understanding of them is still preliminary partly because few genome sequences are available. Here, the draft genome of Sulfobacillus thermosulfidooxidans strain ST was deciphered to obtain a comprehensive insight into the genetic content and to understand the cellular mechanisms necessary for its survival. Furthermore, the expressions of key genes related with iron and sulfur oxidation were verified by semi-quantitative RT-PCR analysis. The draft genome sequence of Sulfobacillus thermosulfidooxidans strain ST, which encodes 3225 predicted coding genes on a total length of 3,333,554 bp and a 48.35% G+C, revealed the high degree of heterogeneity with other Sulfobacillus species. The presence of numerous transposases, genomic islands and complete CRISPR/Cas defence systems testifies to its dynamic evolution consistent with the genome heterogeneity. As expected, S. thermosulfidooxidans encodes a suit of conserved enzymes required for the oxidation of inorganic sulfur compounds (ISCs). The model of sulfur oxidation in S. thermosulfidooxidans was proposed, which showed some different characteristics from the sulfur oxidation of Gram-negative A. ferrooxidans. Sulfur oxygenase reductase and heterodisulfide reductase were suggested to play important roles in the sulfur oxidation. Although the iron oxidation ability was observed, some key proteins cannot be identified in S. thermosulfidooxidans. Unexpectedly, a predicted sulfocyanin is proposed to transfer electrons in the iron oxidation. Furthermore, its carbon metabolism is rather flexible, can perform the transformation of pentose through the oxidative and non-oxidative pentose phosphate pathways and has the ability to take up small organic compounds. It encodes a multitude of heavy metal resistance systems to adapt the heavy metal-containing environments.
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China; Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, China.
authors.forename: Xue
authors.initials: X
authors.lastname: Guo
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China; Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, China.
authors.forename: Huaqun
authors.initials: H
authors.lastname: Yin
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China; Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, China.
authors.forename: Yili
authors.initials: Y
authors.lastname: Liang
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China; Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Hu
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China; Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, China.
authors.forename: Xishu
authors.initials: X
authors.lastname: Zhou
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China.
authors.forename: Yunhua
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China.
authors.forename: Liyuan
authors.initials: L
authors.lastname: Ma
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China.
authors.forename: Xian
authors.initials: X
authors.lastname: Zhang
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China; Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, China.
authors.forename: Guanzhou
authors.initials: G
authors.lastname: Qiu
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China; Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, China.
authors.forename: Xueduan
authors.initials: X
authors.lastname: Liu
mesh_terms: D000222:Adaptation, Physiological; D064112:Clustered Regularly Interspaced Short Palindromic Repeats; D004734:Energy Metabolism / Q000235:genetics; D020745:Genome, Archaeal; D053858:Metabolic Networks and Pathways / Q000235:genetics; D058977:Molecular Sequence Annotation; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D016944:Sulfolobus / Q000235:genetics* / Q000378:metabolism