Isolation and characterization of Ferroplasma thermophilum sp. nov., a novel extremely acidophilic, moderately thermophilic archaeon and its role in bioleaching of chalcopyrite.

摘要

Aims: To isolate Ferroplasma thermophilum L1T 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 L1T, was isolated from a chalcopyrite-leaching bioreactor. The morphological, biochemical and physiological characteristics of strain L1T and its role in bioleaching of chalcopyrite were studied. Strain L1T was a nonmotile coccus that lacked cell wall. Strain L1T had a temperature optimum of 45.C and the optimum pH for growth was 1.0. Strain L1T 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 L1T 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 L1T and its role in bioleaching of sulfide ores.