Activity and diversity of sulfate- and methane-based pathways of anaerobic chitin and N-acetylglucosamine degradation in marine sediments.

Complex carbon inputs like chitin preserve higher microbial diversity and promote diverse microbial interactions in marine sediments, compared to monomer N-acetylglucosamine.

• Why it matters: Understanding how complex organic carbon influences sediment microbial communities is crucial because these microbes significantly contribute to oceanic carbon and nitrogen cycling, yet their diversity maintenance mechanisms are poorly understood.
• What they did: Researchers conducted multi-month microcosm experiments with sediments amended with chitin or N-acetylglucosamine, analyzing microbial diversity, community structure, and functional interactions through geochemical, 16S rRNA gene sequencing, and metagenomics.
• The result: Complex carbon inputs fostered unique microbial assemblages, including diverse methanogenic lineages, and drove the assembly of functional microbial networks, especially in microoxic sediments, highlighting the role of carbon complexity in microbial diversity and interactions.