TY - JOUR
T1 - Characterization and identification of an iron-oxidizing, Leptospirillum-like bacterium, present in the high sulfate leaching solution of a commercial bioleaching plant
AU - Romero, Jaime
AU - Yañez, Carolina
AU - Vásquez, Mónica
AU - Moore, Edward R.B.
AU - Espejo, Romilio T.
N1 - Funding Information:
This work was supported by a Grant 1961216 from FONDECYT.
PY - 2003/6
Y1 - 2003/6
N2 - Most copper bioleaching plants operate with a high concentration of sulfate salts, caused by the continuous addition of sulfuric acid and the recycling of the leaching solution. Since the bacteria involved in bioleaching have been generally isolated at low sulfate concentrations, the bacterial population present in the high-sulfate (150 gl-1) leaching solution, employed in a copper production plant, was investigated. The iron-oxidizing bacteria able to grow in the leaching solution were enriched by several batch cultivations and, after serial dilution, an abundant bacterial strain was isolated. This strain, called LA, exhibited a relatively constant rate of iron-oxidation in media containing sulfate ions at concentrations ranging from 10 to 150 gl-1. Culture collection strains of Leptospirillum ferrooxidans and Acidithiobacillus ferrooxidans showed limited abilities to grow at sulfate ion concentrations higher than 70 gl-1. In spite of its tolerance to high sulfate concentrations, strain LA was as sensitive to NaCl as A. ferrooxidans. Comparative sequence analysis of the 16S rRNA gene of strain LA indicated that it is phylogenetically related to strains described as Leptospirillum ferrooxidans. Bacterial community DNA restriction patterns of 16S rRNA genes suggested that strain LA was a minor component of the bacterial population present in leaching solution, but is abundant in ore leached with this solution.
AB - Most copper bioleaching plants operate with a high concentration of sulfate salts, caused by the continuous addition of sulfuric acid and the recycling of the leaching solution. Since the bacteria involved in bioleaching have been generally isolated at low sulfate concentrations, the bacterial population present in the high-sulfate (150 gl-1) leaching solution, employed in a copper production plant, was investigated. The iron-oxidizing bacteria able to grow in the leaching solution were enriched by several batch cultivations and, after serial dilution, an abundant bacterial strain was isolated. This strain, called LA, exhibited a relatively constant rate of iron-oxidation in media containing sulfate ions at concentrations ranging from 10 to 150 gl-1. Culture collection strains of Leptospirillum ferrooxidans and Acidithiobacillus ferrooxidans showed limited abilities to grow at sulfate ion concentrations higher than 70 gl-1. In spite of its tolerance to high sulfate concentrations, strain LA was as sensitive to NaCl as A. ferrooxidans. Comparative sequence analysis of the 16S rRNA gene of strain LA indicated that it is phylogenetically related to strains described as Leptospirillum ferrooxidans. Bacterial community DNA restriction patterns of 16S rRNA genes suggested that strain LA was a minor component of the bacterial population present in leaching solution, but is abundant in ore leached with this solution.
KW - Bioleaching
KW - Extremophiles
KW - Leptospirillum ferrooxidans
KW - Sulfate
UR - http://www.scopus.com/inward/record.url?scp=0037756704&partnerID=8YFLogxK
U2 - 10.1016/S0923-2508(03)00037-8
DO - 10.1016/S0923-2508(03)00037-8
M3 - Article
C2 - 12837511
AN - SCOPUS:0037756704
VL - 154
SP - 353
EP - 359
JO - Research in Microbiology
JF - Research in Microbiology
SN - 0923-2508
IS - 5
ER -