Meeting Abstract
Microbiomes, representing the collective microbial community living in or on an individual, are recognized as having significant impacts on the development, health, and disease status of multicellular hosts. Given that the mechanistic basis between an individual’s genome and phenome requires consideration at different levels of biological organization, this should include interactions with, and the organization of, microbial consortia. As another model in understanding consortia organization, we elucidated the genetic constituents amongst phenotypically similar (and hypothesized functionally-analogues) layers in the unique laminated orange cyanobacterial-bacterial crusts endemic to Hawaii’s anchialine ecosystem. High-throughput amplicon sequencing of ribosomal RNA hypervariable regions revealed microbial richness increasing by crust layer depth, with a given layer more similar to different layers from the same geographic site than to their phenotypically analogous one from different sites. Furthermore, samples from sites on the same island were more similar to each other, regardless of which layer they originated from, than to analogous layers from another island. Notably, cyanobacteria and algae were abundant in all surface and bottom layers, with anaerobic and chemoautotrophic taxa concentrated in the middle two layers, suggesting oxygenation from both above and below. Thus, arrangement of oxygenated vs. anoxygenated niches in these orange crusts are functionally distinct relative to other examined laminated cyanobacterial-bacterial communities, with convergent evolution due to similar environmental conditions a likely driver for these phenotypically comparable but genetically distinct microbial consortia.
