H Zhou1, R Zhang, P Hu, W Zeng, Y Xie, C Wu, G Qiu. 1. School of Minerals Processing and Bioengineering, Central South University, Changsha, PR China.
Abstract
AIMS: To isolate Ferroplasma thermophilum L1(T) from a low pH environment and to understand its role in bioleaching of chalcopyrite. METHODS AND RESULTS: Using serial dilution method, a moderately thermophilic and acidophilic ferrous iron-oxidizing archaeon, named L1(T), was isolated from a chalcopyrite-leaching bioreactor. The morphological, biochemical and physiological characteristics of strain L1(T) and its role in bioleaching of chalcopyrite were studied. Strain L1(T) was a nonmotile coccus that lacked cell wall. Strain L1(T) had a temperature optimum of 45 degrees C and the optimum pH for growth was 1.0. Strain L1(T) was capable of chemomixotrophic growth on ferrous iron and yeast extract. Results of fatty acid analysis, DNA-DNA hybridization, G+C content, and analysis based on 16S rRNA gene sequence indicated that strain L1(T) should be grouped in the genus Ferroplasma, and represented a new species, Ferroplasma thermophilum. Ferroplasma thermophilum in combination with Acidithiobacillus caldus and Leptospirillum ferriphilum could improve the copper dissolution in bioleaching of chalcopyrite. CONCLUSIONS: A novel extremely acidophilic, moderately thermophilic archaeon isolated from a bioleaching reactor has been identified as F. thermophilum that played an important role in bioleaching of chalcopyrite at low pH. SIGNIFICANCE AND IMPACT OF THE STUDY: This study contributes to understand the characteristics of F. thermophilum L1(T) and its role in bioleaching of sulfide ores.
AIMS: To isolate Ferroplasma thermophilum L1(T) from a low pH environment and to understand its role in bioleaching of chalcopyrite. METHODS AND RESULTS: Using serial dilution method, a moderately thermophilic and acidophilic ferrous iron-oxidizing archaeon, named L1(T), was isolated from a chalcopyrite-leaching bioreactor. The morphological, biochemical and physiological characteristics of strain L1(T) and its role in bioleaching of chalcopyrite were studied. Strain L1(T) was a nonmotile coccus that lacked cell wall. Strain L1(T) had a temperature optimum of 45 degrees C and the optimum pH for growth was 1.0. Strain L1(T) was capable of chemomixotrophic growth on ferrous iron and yeast extract. Results of fatty acid analysis, DNA-DNA hybridization, G+C content, and analysis based on 16S rRNA gene sequence indicated that strain L1(T) should be grouped in the genus Ferroplasma, and represented a new species, Ferroplasma thermophilum. Ferroplasma thermophilum in combination with Acidithiobacillus caldus and Leptospirillum ferriphilum could improve the copper dissolution in bioleaching of chalcopyrite. CONCLUSIONS: A novel extremely acidophilic, moderately thermophilic archaeon isolated from a bioleaching reactor has been identified as F. thermophilum that played an important role in bioleaching of chalcopyrite at low pH. SIGNIFICANCE AND IMPACT OF THE STUDY: This study contributes to understand the characteristics of F. thermophilum L1(T) and its role in bioleaching of sulfide ores.
Authors: Paula Benevides de Morais; Denise Rodrigues de Souza; Francisca Maria Pinheiro de Sousa; Kleverson Wessel de Oliveira; Raphael Sanzio Pimenta Journal: Braz J Microbiol Date: 2011-06-01 Impact factor: 2.476