Abstract from C-DEBI:

Deep marine sediments harbor an abundance of microbial cells that, if active, are likely to exert a strong influence on element biogeochemical cycling. Despite decades of study, our understanding of the fraction of cells that are active in situ and the metabolic processes that sustain them remain under-explored. We propose an integrated set of analyses aimed at unraveling the links between geochemical heterogeneity, cellular viability and synthesis, and metabolism along a vertical depth profile in four sediment cores collected during the North Atlantic long coring expedition. These sediment columns exhibit varying levels of organic carbon and differences in the degree of oxygen penetration along the depth profile which we hypothesize exert strong influence on the extent and nature of microbial life. Most probable number assays containing nine different selective enrichment conditions were initiated using subsamples from these cores in Nov. 2014. Separate subsamples were preserved for use in measuring rates of secondary production. Multivariate modeling tools will be applied to integrate these measurements with co-registered geochemical measurements, cell counts, and molecular data provided by collaborators. This work will provide new insight into the dynamic interplay between O2 and organic carbon and microbial activity, viability, and productivity in deep marine sediments.

NOTE: This project follows the C-DEBI program Data Management Plan (PDF).