Unravelling core microbial metabolisms in the hypersaline microbial mats of Shark Bay using high-throughput metagenomics

Shark Bay's hypersaline microbial mats, potential analogues of Earth's earliest ecosystems, exhibit unique metabolic pathways not found elsewhere. A first-of-its-kind shotgun metagenomic analysis revealed that these mats are dominated by Proteobacteria, Cyanobacteria, and Bacteroidetes, with distinct microbial community structures compared to Highbourne Cay (Bahamas). Notably, Shark Bay mats feature alternative non-rubisco-based carbon metabolism pathways, such as the reductive TCA cycle and 3-hydroxypropionate/4-hydroxybutyrate cycles, which are absent in other studied ecosystems. Additionally, evidence suggests novel nitrogen and heavy metal cycling processes involving arsenic, mercury, copper, and cadmium. Archaea, highly represented here, may play critical roles in ecosystem function, highlighting Shark Bay's microbial mats as unique and complex ecosystems warranting further study.

Ruvindy, R., White III, R. A., Neilan, B. A., & Burns, B. P. (2015). Unravelling core microbial metabolisms in the hypersaline microbial mats of Shark Bay using high-throughput metagenomics. The ISME Journal, 10(1), 183–196. https://doi.org/10.1038/ismej.2015.87