Awardee: Jesse Colangelo-Lillis (University of Colorado, Boulder)
Degree: Ph.D. Earth & Planetary Science, McGill University (2016)
Advisor: Boswell A. Wing (University of Colorado, Boulder)
Amount: $226,540.00
Award Dates: November 1, 2017 — January 31, 2020


The MEGA Analogue for Subsurface Sedimentary In-Vivo Evolution (MASSIVE) Plate project aimed to develop an experimental growth platform to evaluate adaptation under the selection pressure of diminished quality of organic carbon. This pressure was intended to emulate what is considered the greatest obstacle to robust microbial growth in marine sediments, and has been argued to result in communities shaped only by selective filtration of communities at the sediment seawater interface concomitant with progressive burial (Petro et al. 2019, Kirkpatrick et al. 2019). An anaerobic experimental platform for spatially and temporally resolved growth was successfully developed, and anaerobic sulfate-reducing bacteria (SRB) were grown on it. The rate of growth was prohibitive to completion of initially envisioned experiments, and complimentary work was undertaken in Balch tubes. In this growth environment, SRB were demonstrated to increase total yield on combinations of initially utilizable and non-utilizable organic carbon substrates following growth with exposure to both. This did not translate to utilization of solely the novel organic carbon sources, suggesting that the mechanism of utilization required the presence of initially utilizable organic carbon. This work supports the current sentiment that adaptation to utilization of progressively more recalcitrant organic carbon serves as a (possibly insurmountable) bottleneck to microbial adaptation and community assembly in marine sediments.