title: Resolution of carbon metabolism and sulfur-oxidation pathways of Metallosphaera cuprina Ar-4 via comparative proteomics.
abstract: Metallosphaera cuprina is able to grow either heterotrophically on organics or autotrophically on CO2 with reduced sulfur compounds as electron donor. These traits endowed the species desirable for application in biomining. In order to obtain a global overview of physiological adaptations on the proteome level, proteomes of cytoplasmic and membrane fractions from cells grown autotrophically on CO2 plus sulfur or heterotrophically on yeast extract were compared. 169 proteins were found to change their abundance depending on growth condition. The proteins with increased abundance under autotrophic growth displayed candidate enzymes/proteins of M. cuprina for fixing CO2 through the previously identified 3-hydroxypropionate/4-hydroxybutyrate cycle and for oxidizing elemental sulfur as energy source. The main enzymes/proteins involved in semi- and non-phosphorylating Entner-Doudoroff (ED) pathway and TCA cycle were less abundant under autotrophic growth. Also some transporter proteins and proteins of amino acid metabolism changed their abundances, suggesting pivotal roles for growth under the respective conditions.
  
  
  CONCLUSIONS
  The described work is of great significance: For general microbiology: How do extremophile organisms use their unique metabolic capabilities in adapting to autotrophic and hetetrotrophic growth conditions? Which are important enzymes involved in the metabolic adaptation and which enzyme candidate should be investigated in more detail with microbiological/biochemical approaches? For applied microbiology: Which are the key enzymes and reaction pathways for sulfur oxidation and autotrophic growth? This knowledge should accelerate future design of improved bioleaching processes in biomining industries or bioremediation.
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, PR China.
authors.forename: Cheng-Ying
authors.initials: CY
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, PR China.
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, PR China.
authors.forename: Xu
authors.initials: X
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, PR China.
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: You
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, PR China; Envrionmental Microbiology and Biotechnology Research Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, PR China. Electronic address: liusj@im.ac.cn.
authors.forename: Shuang-Jiang
authors.initials: SJ
authors.lastname: Liu
authors.affiliation: Plant Biochemistry, Ruhr University Bochum, Bochum, Germany. Electronic address: ansgar.poetsch@rub.de.
authors.forename: Ansgar
authors.initials: A
authors.lastname: Poetsch
mesh_terms: D019843:Archaeal Proteins / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism*; D010084:Oxidation-Reduction; D040901:Proteomics; D016943:Sulfolobaceae / Q000378:metabolism*; D013455:Sulfur / Q000378:metabolism*
chemical_list: D019843:Archaeal Proteins; D002245:Carbon Dioxide; D013455:Sulfur; D002244:Carbon
keywords: Autotrophy; Bioleaching; Extremophile; Heterotrophy; Industrial microbiology; Quantitative proteomics