Impact of complex carbon on deep sea sediment microbial community structure and function

Deep sea sediments cover two thirds of the planet's surface and are critical contributors to global carbon and nutrient cycles. Despite their importance, the drivers of microbial community structure in these systems are poorly understood. In order to determine the effect of complex carbon on deep sea sediment community structure and function, we conducted highly replicated incubations of serially diluted whale fall sediment with the complex ubiquitous marine polymer chitin and its monomer N-acetylglucosamine. With 16S rRNA gene sequencing, we were able to demonstrate the impact of carbon complexity on these sediment communities, particularly on organisms hypothesized to carry out the low-energy terminal respiratory processes of sulfate reduction and methanogenesis.