Download Full Text (582 KB)


As greenhouse gas emissions contribute to global warming and an increase in CO2 concentration in the earth’s atmosphere, the scientific community is under pressure not just to examine new technologies to reduce emissions, but also to consider the effect that increased CO2 concentration has on our terrestrial and marine ecosystems. In marine ecosystems, atmospheric CO2 dissolves and reacts with water to form carbonic acid. This diprotic acid then dissociates, contributing to a lowered pH of ocean water and affecting all levels of marine life. Fortunately, nature already has carbonate reduction mechanisms in place that can reduce the harmful effects of ocean acidification. Being able to identify individual bacteria in biological carbonate-fixing consortia can lead to adaptive systems engineered around biofilms. In this study, environmental samples taken from defined sites the dark marine biosphere (ocean depth of 2100-2300 meters) in the Gulf of Mexico were grown in a number of selective medias with defined carbonate contents. Bacterial samples were then analyzed using ion chromatography to measure carbonate consumption as a function of time. The data suggests that by selectively pressuring environmental consortia from the dark marine biosphere toward the purpose of fixing carbon, mechanisms and pathways can be generated to control the level of CO2 in the marine environment.

Publication Date


Project Designation

Honors Thesis

Primary Advisor

Justin C Biffinger

Primary Advisor's Department



Stander Symposium poster


Presenter: Anna Gwendolyn Blair

Understanding Chemolithotrophic Reduction Mechanisms from the Dark Marine Biosphere