Sulfate Reduction for Bioremediation of AMD Facilitated by an Indigenous Acid- and Metal-tolerant Sulfate-Reducer.

In this study, an acid-tolerant sulfate reducing bacterium, strain S4 was isolated from the mud of an AMD storage pond in Vietnam via enrichment in anoxic mineral medium at pH5. Comparative analyses of sequences of the 16S rRNA gene and dsrB gene involving in sulfate reduction revealed that the isolate belonged to the genus Desulfovibrio, most closely related to Desulfovibrio oxamicus (with 99% homology in 16S rDNA sequence and 98% homology in dsrB gene sequence). DGGE analyses of dsrB genes showed that strain S4 represented one of the two most abundant groups developed in the enrichment culture. Notably, strain S4 was capable of reducing sulfate in low pH environments (from 2 and above), and resistance to extremely high concentration of heavy metals (Fe 3000 mg/l, Zn 100 mg/l, Cu 100 mg/l). In a batch incubation experiment in synthetic AMD with pH 3.5, strain S4 showed strong effects in facilitating growth of a neutrophilic, metal sensitive Desulfovibrio sp. strain SR4H which was not capable of growing alone in such environment. Thus, it is postulated that under extreme conditions such as AMD environment, acid- and metal-tolerant SRB like strain S4 would facilitate the growth of other widely distributed SRB by starting to reduce sulfate at low pH, thus increasing pH and lowering the metal concentration in the environment. Owing such unique physiological characteristics, strain S4 showed a great application potential for sustainable remediation of AMD. PMID: 32160701 ...
Source: Journal of Microbiology and Biotechnology - Category: Biotechnology Authors: Tags: J Microbiol Biotechnol Source Type: research