Note: This story was originally published by Oak Ridge National Laboratory on May 31.
A team led by the U.S. Department of Energy’s Oak Ridge National Laboratory has identified a novel microbial process that can break down toxic methylmercury in the environment, a fundamental scientific discovery that could potentially reduce mercury toxicity levels and support health and risk assessments.
Methylmercury is a neurotoxin that forms in nature when mercury interacts with certain microbes living in soil and waterways. It accumulates at varying levels in all fish—particularly large predatory fish such as tuna and swordfish—and, when consumed in large quantities, can potentially cause neurological damage and developmental disorders, especially in children.
A previous ORNL-led study, published in Science in 2013, unlocked the genetic code that led scientists to accurately identify microbes responsible for methylmercury production in the environment. Following this finding, the ORNL team has now discovered which bacteria perform the reverse process, called demethylation. Details are published in Science Advances.
“Much attention has focused on mercury methylation or how methylmercury forms, but few studies to date have examined microbial demethylation, or the breakdown of methylmercury at environmentally relevant conditions,” said Baohua Gu, co-author and a team lead in ORNL’s Mercury Science Focus Area. [Read more…]