Southern California oxygen minimum zone Metagenome

We propose to use shotgun metagenomic sequencing to address how the interface of the OMZ with shallow subsurface sediments impacts the microbial community composition and ecosystem function. Preliminary analyses reveal that despite differences in geochemistry, microbial subsurface sediment communities, determined via 16S rRNA, inside and outside of the OMZ are similar. We hypothesize that these organisms may be expressing different functional genes to survive in these different environments and that similarities in microbial diversity is disguising changes in active metabolism or is reflective of dormant cells waiting for a change of in situ geochemistry. This question is relevant to understanding the assembly and function of deeper subsurface communities, which may be reflective of burial and persistence of components of the surface community. PI Alexis Pasulka, Caltech