The Different Effects of Molybdate on Hg(II) Bio-methylation in Aerobic and Anaerobic Bacteria

In nature, methylmercury (MeHg) is primarily generated through microbial metabolism. The ability of bacterial Hg(II) methylation is depended by bacterial properties and environmental factors. It is widely known that molybdate as a metabolic analogue can inhibit the sulfate reduction process and affect the growth and methylation of SRB. However, molybdate can be involved in various intracellular metabolisms as a molybdenum cofactor after it enters into the cell, so could its concentration fluctuation also affect the growth and methylation of aerobic mercury methylation strains? From this perspective, we used aerobic strains RaouLtella terrigena (TGRB3) and Pseudomonas putida bacteria (TGRB4), and obligate anaerobic strains sulfate-reducing bacteria Desulfomicrobium escambiense CGMCC 1.3481 (SRB1) as experimental strains. In addition, we further explored this by analyzing transcriptomic data of the facultative mercury-methylated strain TGRB3 in an aerobic mercuric environment.