Copper Tolerance of Novel Rhodotorula sp. Yeast Isolated from Gold Mining Ore in Gia Lai, Vietnam

In this study, twenty-five yeast strains were isolated from soil samples collected in the gold mining ore in Gia Lai, Vietnam. Among them, one isolate named GL1(T) could highly tolerate Cu2+ up to 10 mM, and the isolates could also grow in a wide range of pH (3-7), and temperature (10-40 degrees C). Dried biomass of GL1 was able to remove Cu2+ effectively up to 90.49% with a maximal biosorption capacity of 18.1 mg/g at pH 6, temperature 30 degrees C, and incubation time 60 min. Sequence analysis of rDNA indicated this strain was closely related to Rhodotorula mucilaginosa but with 1.53 and 3.46% nucleotide differences in the D1/D2 domain of the 28S rRNA gene and the ITS1-5.8S rRNA gene-ITS2 region sequence, respectively. Based on phylogenetic tree analysis and the biochemical characteristics, the strain appears to be a novel Rhodotorula species, and the name Rhodotorula aurum sp. nov. is proposed. This study provides us with more information about heavy metal-tolerant yeasts and it may produce a new tool for environmental control and metal recovery operations.

Automated summary

In this study, 25 yeast strains were isolated from soil samples collected in gold mining ore in Gia Lai, Vietnam. Among them, one isolate named GL1(T) exhibited high tolerance to Cu2+ and could grow in a wide range of pH and temperature. The dried biomass of the isolate showed effective removal of Cu2+, and phylogenetic analysis suggested it belonged to a novel Rhodotorula species.