Screening of Methylmercury-Resistance in Bacterial Culture Strains Isolated from Soil of Oak Ridge Reservation Site, USA

Abstract

Abstract Methylmercury (MeHg) is a highly toxic heavy metal that severely threatens biota worldwide and causes neurotoxicity in humans. The seriousness of toxicity of this neurotoxin is characterized by its ability to augment food chains. The general population is primarily exposed to MeHg by consuming contaminated fish and other marine food. In this study, Pseudomonas sp. strains SM-1, SM-2, SM-3, SM-4, SM-5, SM-6, SM-8, and SM-11 previously isolated from contaminated soil at the Oak Ridge Reservation site, U.S. Department of Energy (DOE) facility, were screened for methylmercury (MeHg) tolerance level through the determination of minimum inhibitory concentration (MIC) using Bioscreen C Pro automated microbiology growth curve analysis system. The results showed that these bacterial strains exhibited the MeHg MIC, which ranged from 1250 to 2000 µg/L. Overall, data indicated that the Pseudomonas strains could grow at high methylmercury concentrations and could be tested for remediation of MeHg in polluted environmental samples.