ERC Consolidator: Conductive minerals as electric conduits in methane cycling

This proposal aims to gain a fundamental understanding of the impact of anthropogenic conductive particles on methane emissions. We recently showed that conductive particles are vital for the interspecies cross-feeding of a methane-producing consortium from the Baltic Sea. Previous to that, we showed that conductive particles accelerate methane production in synthetic dual-species consortia that typically function via direct electron transfer. Others showed that conductive particles may also stimulate anaerobic methane oxidation. For the latter, the reports are scarce and contradictory. It is mysterious how microorganisms interact with the conductive particles and how conductive particles affect the methane cycle in the environment. These knowledge gaps we will study here. We will use synthetic consortia, enriched environmental consortia, and whole sediment cores. We will identify marker genes for microbe-particle contacts by combining expression studies with targeted gene-deletion and physicochemical cell surface studies. The marker genes we can then use to track similar microbe-conductive particle associations in the environment. We will examine the link between increased anthropogenic particle input and methane emissions in environments from the Mediterranean to the Arctic where higher particle input is likely. I expect to deliver fundamental knowledge about the microorganisms involved in methane transformations by anthropogenically derived conductive particles.