title: Evolution of Sulfobacillus thermosulfidooxidans secreting alginate during bioleaching of chalcopyrite concentrate.
abstract: OBJECTIVE
  To explore the distribution disciplinarian of alginate on the chalcopyrite concentrate surface during bioleaching.
  
  
  RESULTS
  The evolution of Sulfobacillus thermosulfidooxidans secreting alginate during bioleaching of chalcopyrite concentrate was investigated through gas chromatography coupled with mass spectrometry (GC-MS) and confocal laser scanning microscope (CLSM), and the critical synthetic genes (algA, algC, algD) of alginate were analysed by real-time polymerase chain reaction (RT-PCR). The GC-MS analysis results indicated that there was a little amount of alginate formed on the mineral surface at the early stage, while increasing largely to the maximum value at the intermediate stage, and then kept a stable value at the end stage. The CLSM analysis of chalcopyrite slice showed the same variation trend of alginate content on the mineral surface. Furthermore, the RT-PCR results showed that during the early stage of bioleaching, the expressions of the algA, algC and the algD genes were all overexpressed. However, at the final stage, the algD gene expression decreased in a large scale, and the algA and algC decreased slightly. This expression pattern was attributed to the fact that algA and algC genes were involved in several biosynthesis reactions, but the algD gene only participated in the alginate biosynthesis and this was considered as the key gene to control alginate synthesis.
  
  
  CONCLUSIONS
  The content of alginate on the mineral surface increased largely at the beginning of bioleaching, and remained stable at the end of bioleaching due to the restriction of algD gene expression.
  
  
  CONCLUSIONS
  Our findings provide valuable information to explore the relationship between alginate formation and bioleaching of chalcopyrite.
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China.|Key Laboratory of Biometallurgy, Ministry of Education, Changsha, China.
authors.forename: R-L
authors.initials: RL
authors.lastname: Yu
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China.
authors.forename: A
authors.initials: A
authors.lastname: Liu
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Yu
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China.
authors.forename: T
authors.initials: T
authors.lastname: Peng
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China.|Key Laboratory of Biometallurgy, Ministry of Education, Changsha, China.
authors.forename: X
authors.initials: X
authors.lastname: Wu
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China.|Key Laboratory of Biometallurgy, Ministry of Education, Changsha, China.
authors.forename: L
authors.initials: L
authors.lastname: Shen
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China.|Key Laboratory of Biometallurgy, Ministry of Education, Changsha, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China.|Key Laboratory of Biometallurgy, Ministry of Education, Changsha, China.
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China.|Key Laboratory of Biometallurgy, Ministry of Education, Changsha, China.
authors.forename: X
authors.initials: X
authors.lastname: Liu
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China.|Key Laboratory of Biometallurgy, Ministry of Education, Changsha, China.
authors.forename: G
authors.initials: G
authors.lastname: Qiu
authors.affiliation: CSIRO Process Science and Engineering, Clayton, Vic., Australia.
authors.forename: M
authors.initials: M
authors.lastname: Chen
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, China.|Key Laboratory of Biometallurgy, Ministry of Education, Changsha, China.|CSIRO Process Science and Engineering, Clayton, Vic., Australia.
authors.forename: W
authors.initials: W
authors.lastname: Zeng
mesh_terms: D000464:Alginates / Q000378:metabolism*; D053898:Biosynthetic Pathways; D000068016:Eubacteriales / Q000378:metabolism*; D003300:Copper / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D020723:Glucuronic Acid / Q000378:metabolism; D006603:Hexuronic Acids / Q000378:metabolism; D008903:Minerals / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D008903:Minerals; C012819:chalcopyrite; D003300:Copper; D020723:Glucuronic Acid
keywords: alginate; bioleaching; confocal laser scanning microscope; extracellular polymeric substances; real-time polymerase chain reaction