PI: Everett C. Salas (Photon Systems)
Co-I: Jason B. Sylvan (University of Southern California)
Amount: $49,417.00
Award Dates: August 1, 2012 — March 30, 2014


The subseafloor basaltic aquifer is known to be home to microbial communities, at least in young ocean crust.  Based on its predicted size, modeled using temperature gradients and 120°C as a cutoff for microbial life, it is predicted to host a biomass equal to or larger than that found in subseafloor sediments.  However, to date, these predictions remain unconstrained, with no real data available.  The goal of our C-DEBI project was to develop a method for quantifying cell biomass in subseafloor basement samples and, if possible, to scan the same samples with deep-UV scanning technology to determine the spatial heterogeneity of microbial samples.  Through two visits to the lab of Fumio Inagaki at Japan Agency for Marine-Earth Science Technology (JAMSTEC) in Kochi Japan, and with training from Yuki Morono, we were able to develop a method and successfully quantify microbes in subseafloor basaltic samples from the Louisville Seamount Chain (IODP Expedition 330, 65-75 Ma rocks) and the Juan de Fuca Ridge flank (3 Ma rocks).  Through our international collaboration, we now know that biomass in these basement environments are generally low (<104 cells cm-3) and this will allow us to model global biomass distributions in subseafloor basement. Deep-UV analysis of rocks was attempted, but results remained difficult to interpret.  Therefore, this analysis remains a future goal.