N-158. A Novel Species of Haloanerobium Identified from a Haloalkaline Lake Has the Potential to Contribute to Biodiesel Production

M. B. Begeman1, M. R. Mormile2, H. C. Pinkart3, J. D. Wall1, D. A. Elias1;
1Univ. of Missouri, Columbia, MO, 2Missouri Univ. of Science and Technology, Rolla, MO, 3Central Washington Univ., Ellensburg, WA.

Soap Lake in central Washington State is highly saline and alkaline, heavily buffered by carbonate and bicarbonate, and meromictic. The monimolimnion lower layer is anaerobic with sulfide ranging from 50-200mM, a pH of 9.9, and 14% salinity. The goal of this work was to characterize microorganisms that may exhibit novel properties for purposes ranging from yielding a better understanding of early Earth microbiota, to bioremediation and enhancement of biofuel production. An organism was isolated from monimolimnion sediments and identified as having the ability to respire elemental sulfur with various sugars. Culture purity was determined by serial dilution and microscopic investigation. To date, single colony isolation has been unsuccessful. This is largely due to the high salinity and pH of the medium that causes substantial precipitation post autoclaving. A number of analyses have been performed in order to characterize the metabolism of the isolate. The isolate is a rod shaped, non-motile, obligate anaerobe that grows with pHs from 7.5-12.5 and NaCl from 2.5%-15.0%, optima being 11.0 and 10%, respectively. Early results showed that lactate supported growth, but the organism appears to prefer to metabolize a variety of sugars in the presence of sulfur and small amounts of yeast extract. Sugars metabolized were glucose, pyruvate, fructose, ribose, cellobiose, and glycerol at the stated pH and salinity. Amplification and sequencing of the16S rDNA revealed that the isolate is most closely associated with the genus of Haloanerobium, with a 98% sequence similarity to Haloanaerobium acetoethylicus. Analysis of the culturing medium during growth via HPLC and GC revealed that the primary metabolic products from sugar oxidations were acetate, H2, and CO2. However, with glucose or glycerol, ethanol was also present. Because glycerol is a major waste product (up to 10%) in the waste flow during biodiesel production, and the waste stream is typically at pH 8 or higher, most organisms cannot tolerate these conditions. This novel isolate has the potential to turn an undesirable waste into a second desirable biofuel from the same precursors as biodiesel.

143/N. Molecular Microbial Ecology - Communities - II

Tuesday, 10:30 am | Poster Hall