MICROBIAL ISOPRENE REDUCTION TIED TO GREENHOUSE GAS REMOVAL IN DEEP-SEA CARBONATES AND EUCALYPTUS-LEAVE SEDIMENTS

Isoprene is the most abundantly produced biogenic volatile organic compound and a critical climate-active atmospheric gas of similar abundance to the potent greenhouse gas methane. Isoprene is also the forgotten piece of the puzzle to tackling climate change. Every form of life produces isoprene but up-to-date, data rarely exist about its global biogeochemical cycle. It is highly reactive in the atmosphere affecting methane concentrations and increasing detrimental negative implications on climate, air quality, and health. On the contrary, we know that methane is abundant in the marine and terrestrial subsurface environment. Deep sea carbonates as well as river sediments are hot spots of microorganisms that carry out anaerobic oxidation of methane which plays an important role in the long-term storage and removal of methane from these habitats. Nothing is known about the fate of isoprene and about potential microbial communities with the ability to metabolize isoprene in deep-sea carbonates and eucalyptus-leave sediments potentially affecting methane metabolism. We are seeking to unravel the anaerobic pathways of microbial isoprene degradation and the effect of isoprene abundance and degradation on microbial methane production and oxidation. Here we present the initial results of the reductive metabolism of isoprene in an anaerobic marine and terrestrial environment. Our data show that isoprene is reduced in a methane-oxidizing environment in deep-sea carbonate enrichment cultures and eucalyptus leave-rich sediments. We are currently characterizing the microorganism’s metabolizing methane and isoprene in the enrichment cultures.