“…Solubilization via the microbe-mediated oxidation of Au 0 and later complexation with different types of ions emitted by microorganisms (e.g., thiosulfate, cyanide) has been proposed in several studies [ 55 , 56 , 57 , 58 ]. Sulfur-oxidizing bacteria (SOB) and sulfate-reducing bacteria (SRB) are important microorganism communities populating hypersaline wetlands, determining the sulfur cycle, and playing important roles in the fixation or release of metals, e.g., [ 30 , 59 ]. Dhiman et al [ 60 ] revealed that important communities of SOB exhibit features that promote plant growth, such as the production of hydrogen cyanide, the presence of which minimally affects its microbial activity [ 61 ], although some other SOB groups, such as Thiobacillus , are used to remove cyanide from polluted systems.…”