Enzyme protects bacteria from toxic gold

Abstract

Certain bacteria protect themselves from a toxic form of gold by transforming it into high-purity nanoparticles. Researchers have now identified a gold-reducing enzyme, called GolR, that is a key part of this process. They hope the enzyme—the first gold reductase known to science, they say—could be used to harvest gold from electronic waste ( JACS Au 2022, DOI: 10.1021/jacsau.2c00170 ). The team found GolR in a bacterium called Erwinia sp. IMH, which thrives in gold ore. The bacterium reduces toxic gold(III) compounds, which can generate reactive oxygen species that harm the bacteria, into less toxic gold nanoparticles. “Although this metal is precious to humans, bacteria hate it,” says team member Chuanyong Jing of the Research Center for Eco-Environmental Sciences at the Chinese Academy of Sciences. To find GolR, the researchers studied which of Erwinia ’s genes were spurred into action by gold(III). When they deleted the most activated gene, the