The shift of microbial community under the adjustment of initial and processing pH during bioleaching of chalcopyrite concentrate by moderate thermophiles.
The shift of microbial community under the adjustment of different pH was analyzed by denaturing gradient gel electrophoresis (DGGE). The results indicated, at initial pH 1.0, 2.0 and 3.0, the copper extraction in 22 days amounted to 84.6%, 88.2% and 77.5%, respectively; however, when the initial pH was 2.0, processing pH was adjusted to 1.0 and 3.0 on day 16, the copper extraction in 32 days was 85% and 62.6%, respectively. DGGE analysis showed Acidithiobacillus caldus, Leptospirillum ferriphilum, Sulfobacillus thermosulfidooxidans and Ferroplasma thermophilum existed in bioleaching systems. At initial pH 1.0 and 3.0, S. thermosulfidooxidans and A. caldus were main microorganisms. While at initial pH 2.0, L. ferriphilum, A. caldus and S. thermosulfidooxidans were always detected. At processing pH 1.0 and 3.0, the adjustment of pH greatly inhibited the growth of L. ferriphilum; it was also found microbial community would recover gradually only if pH stimulation did not fatally affect microorganisms.
School of Minerals Processing and Bioengineering, Central South University, Changsha, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha, China.
Runlan
R
Yu
School of Minerals Processing and Bioengineering, Central South University, Changsha, China.
Lijuan
L
Shi
School of Minerals Processing and Bioengineering, Central South University, Changsha, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha, China.
Guohua
G
Gu
School of Minerals Processing and Bioengineering, Central South University, Changsha, China.
Dan
D
Zhou
School of Minerals Processing and Bioengineering, Central South University, Changsha, China.
Long
L
You
CSIRO Process Science and Engineering, Clayton, Victoria, Australia.
Miao
M
Chen
School of Minerals Processing and Bioengineering, Central South University, Changsha, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha, China.
Guanzhou
G
Qiu
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, Victoria, Australia. Electronic address: zengweimin1024@gmail.com.
Weimin
W
Zeng
D001419:Bacteria / Q000187:drug effects / Q000254:growth & development*; D001673:Biodegradation, Environmental / Q000187:drug effects; D003300:Copper / Q000302:isolation & purification*; D058645:Denaturing Gradient Gel Electrophoresis; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000494:pharmacology; D014961:X-Ray Diffraction
C012819:chalcopyrite; D003300:Copper; D007501:Iron
Bioleaching; Canonical Correspondence Analysis; Chalcopyrite; Microbial community; Processing pH stimulation