Silicified Microorganisms and Microorganism-Like Particles in the Groundwater of an Abandoned Coal Mine

Relatively little research has been conducted on the preservation of microorganisms and microbial particles in the groundwater of abandoned mines (GAM). In this study, silicified microorganism-like particles, 50–450 nm in diameter, were found to commonly occur outside microbes and their associated extracellular polymers. These particles comprise a cellular core surrounded by a cortex essentially of silica and are similar in morphology to certainly known microorganisms. The studied samples suggest the preservation of micro-organisms through silicification and add to understanding about how microorganisms in natural water systems undergo biomineralization. Finally, the silicified microorganism-like particles were surrounded by many silica nanoparticles. This study identified a new mode of silica transport in the GAM.