![]() ![]() Here we report, for the first time, that the strain G. Though mercury (Hg) methylation by anaerobic microorganisms and demethylation by aerobic Hg-resistant bacteria have both been extensively studied, little attention has been given to MeHg degradation by anaerobic bacteria, particularly the iron-reducing bacterium Geobacter bemidjensis Bem. Two competing processes controlling the net production and bioaccumulation of neurotoxic methylmercury (MeHg) in natural ecosystems are microbial methylation and demethylation. Finally, we suggest future research directions to further elucidate the chemical and biochemical mechanisms of biotic and abiotic demethylation and their significance in controlling net MeHg production in natural ecosystems. We focus on mechanisms and processes of demethylation and highlight more » the uncertainties and known effects of environmental factors leading to MeHg degradation. In addition, photochemical and chemical demethylation processes are described, including the roles of dissolved organic matter (DOM) and free radicals as well as dark abiotic demethylation in the natural environment about which little is currently known. Very recent research has begun to elucidate a mechanism for the long-recognized mer-independent oxidative demethylation, likely involving some strains of anaerobic bacteria as well as aerobic methane-oxidizing bacteria, i.e., methanotrophs. We describe detoxification by resistant microorganisms that employ the Hg resistance (mer) system to reductively break the carbon–mercury (C–Hg) bond producing methane (CH 4) and inorganic mercuric Hg(II), which is then reduced by the mercuric reductase to elemental Hg(0). Here we review the current knowledge on MeHg degradation and its potential pathways and mechanisms. However, the net methylmercury (MeHg) concentration that accumulates in the environment is equally determined by the rate of MeHg degradation, a complex process mediated by a variety of biotic and abiotic mechanisms, about which our knowledge is limited. This story was originally featured on Fortune.The public and environmental health consequences of mercury (Hg) methylation have drawn much attention and considerable research to Hg methylation processes and their dynamics in diverse environments and under a multitude of conditions. “Our heads are spinning over here-not entirely sure what happens next," one startup founder told Fortune in a private message after the bank failed. Now that SVB is locked up, some startups whose cash is tied up in the bank, are scrambling to figure out how to make payroll and other expenses. Prior to being shut down by regulators, shares of SVB were halted Friday morning after falling more than 60% in premarket trading following a 60% declined on Thursday when the bank sold off a portfolio of US Treasuries and $1.75 billion in shares to cover declining customer deposits. Silicon Valley Bank was shut down on Friday morning by California regulators and was put in control of the U.S. SANTA CLARA, CALIFORNIA - MARCH 10: Employees walk in front of a sign outside of the shuttered Silicon Valley Bank (SVB) headquarters on Main Santa Clara, California. According to a video posted on Twitter, a line of people at another SVB branch pushed out onto the street, even as an "atmospheric river" drenched the area with rain and kept the region under a flood watch. The doors at the bank's Santa Clara, Calif headquarters were closed on Friday, and staffers occasionally popped out to give the bad news to the people assembled outside. ![]() ![]() SANTA CLARA, CALIFORNIA - MARCH 10: A worker (C) tells people that the Silicon Valley Bank (SVB) headquarters is closed on Main Santa Clara, California. ![]()
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