Geochemistry and Microbiology of Extremely Alkaline (Ph > 12) Ground Water in the Calumet Slag -Fill Aquifer

Microbiologists have long believed that highly alkaline conditions are poorly supportive of microbial life, in part because an environment lacking in hydrogen ions (H+) is likely to interfere with the proton motive force, and with the need to maintain a circum-neutral intracellular pH (Horikoshi and Akiba, 1982). Here I describe a diverse microbial community that inhabits extremely alkaline (pH ≈ 12--13) groundwater from the Lake Calumet region Using microbial culturing, genetic sequencing, and microcosm experiments, I confirmed the presence and growth of a variety of alkaliphilic beta-Proteobacteria, Bacillus, and Clostridium species at pH up to 13.2. Many of the bacterial sequences most closely matched other alkaliphiles found more moderately alkaline waters around the world. Oxidation of dihydrogen produced by reaction of water with steel slag is likely a primary energy source to the community. These results extend upward the known range of pH tolerance for a microbial community by as much as two pH units.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Geology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Roadcap, George Stewart

Contributors dc:contributor

• Bethke, Craig M.

• Geochemistry

Language dc:language

eng

Identifier

(MiAaPQ)AAI3131014

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/86525