Physicochemical Properties, Heavy Metal Composition, and Metal Resistant Microorganisms Associated with Gold Mine Tailings in Jebba, Nigeria

Abstract

Mine tailings are a source of unique microorganisms with novel characteristics. This study aims to determine the chemical composition of the soil and water from different locations of an active artisanal gold mine and the microorganisms associated with the mine tailings. The physiochemical analysis of tailings soil and water, HM species, and their carcinogenic and non-carcinogenic effects were determined. Heavy metal resistant bacteria (HMRB) were then isolated using nutrient agar supplemented with metals. The results showed that pH and temperature of the soil and water samples ranged between 6.2- 6.6 and 29–30 °C respectively. The estimated incremental lifetime cancer risk (ILCR) from one location was 7.9E − 6 was the highest. The HMs detected includes Arsenic (As), Mercury (Hg), Cadmium (Cd), and Lead (Pb). Twenty-one HMRB were isolated and they are putatively identified as Staphylococcus spp., Bacillus sp., Salinicoccus halodurans, Staphylococcus chromogenes, Paenibacillus cellulositrophicus, Paenibacillus residui, Sporosarcina globispora, and Streptococcus sp. Analysis of the 16S RNA genes sequences revealed that isolate MS2 has 98.01% similarity to Aneurinibacillus aneurinilyticus. The presence and levels of HMs elucidates the high risk of cancerous and non-cancerous effects borne by artisan gold miners. The isolated HMRB can be further analyzed for possible bioremediation of the site.