Microbial communities play vital roles in biogeochemical cycles, however fundamental Carbon, Nitrogen, and Sulfur cycling processes catalysed by microbial communities are constrained spatially, temporally, and with regard to the different microbial groups involved (Carolan et al., 2015). Shark Bay offers a large distribution of microbial communities across a variety of intertidal plains that are attributed to a complex network of physicochemical factors (Prieto-Barajas et al., 2018). A range of studies have been conducted on these microbial communities from lipid analysis to metagenomics (Wong et al., 2018). Here we sampled microbial mat communities (i.e. smooth, pustular, etc.) occurring in different salinity ranges and during day/night cycles for metatranscriptomic and organic geochemical analyses to detect changes in taxonomic groups and their function. A preliminary investigation of electron accepting reactions using metatranscriptomic data with MG-RAST indicated changes in both bacterial diversity and function of a pustular microbial mat sampled during day and night intervals. In the day time, cyanobacteria are the prominent phyla utilising terminal cytochrome C oxidases, whereas at night time, proteobacteria are the prominent phyla utilising anaerobic respiratory reductase. This indicates an overall shift in community activity from aerobic to anaerobic respiration during a diel cycle. Ongoing work utilising metatranscriptomic and organic geochemical analyses will enable us to detect changes in element cycling taxonomic groups and potentially establish early diagenetic pathways of biomolecules such as the incorporation of sulfur into organic matter.
References
Carolan, M.T., Smith, J.M., Beman, J.M., 2015. Transcriptomic evidence for microbial sulfur cycling in the eastern tropical North Pacific oxygen minimum zone. Frontiers in Microbiology 06, 334.
Prieto-Barajas, C.M., Valencia-Cantero, E., Santoyo, G., 2018. Microbial mat ecosystems: Structure types, functional diversity, and biotechnological application. Electronic Journal of Biotechnology 31, 48–56.
Wong, H.L., White, R.A., Visscher, P.T., Charlesworth, J.C., Vázquez-Campos, X., Burns, B.P., 2018. Disentangling the drivers of functional complexity at the metagenomic level in Shark Bay microbial mat microbiomes. The ISME Journal. doi:10.1038/s41396-018-0208-8