Identification of acetogens in Australian tidal wetland sediment samples

This study focuses on the identification of light-independent CO2 fixing microbes within Australian wetlands mainly comprised of salt marshes and Melaleuca spp.We first identified the microbial diversity in the tidal wetland sediments from two sites within the Yandina Wetlands site at depths of 5 and 7.5 cm below surface. The sites were mostly composed of salt marsh (Met) and Melaleuca forests (Mel). Metagenomic profiling from these samples revealed the presence of microbes mediating CO2 fixation via the Wood-Ljungdahl pathway and Calvin Benson Cycle.We further aimed to isolate acetogens and other microbial groups able to fix CO2 and H2 present in the samples through gas-fermented enrichment cultures (A and B). We identified clostridial acetogens in these enrichment cultures by genome-resolved metagenomic analysis.