August 1, 2013.
Hot Lake is a meromictic, epsomitic lake. It has a phototrophic microbial mat that reassembles every year. The mat community is subjected to large fluctuations of salinity and solar irradiance. PNNL is interested in studying how these communities respond to the fluctuating environment conditions. To date, 70 isolates have been obtained from Hot Lake with the intention of characterizing their physiology to gain a better understanding of how they are naturally functioning in the Hot Lake mat community. I tested eight of these isolates in media designed to mimic the chemistry of Hot Lake with a selection of sugars, amino acids, and organic compounds to see which strains could use which compounds as sole carbon sources. Glucose, glycerol, sucrose, proline, and lactate were each able to be utilized as sole carbon sources by at least half of the strains. Two of these compounds, sucrose and proline, are known to function as intracellular organic osmolytes in bacteria. This allows for the possibility that these compounds were promoting growth by functioning not only as carbon sources, but also as compatible solutes. This work is a first step towards understanding the interactions between the bacteria that are present in the Hot Lake mat.
Pacific Northwest National Laboratory (PNNL)
This material is based upon work supported by the S.D. Bechtel, Jr. Foundation and by the National Science Foundation under Grant No. 0952013 and Grant No. 0934931. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the S.D. Bechtel, Jr. Foundation or the National Science Foundation. This project has also been made possible with support of the National Marine Sanctuary Foundation. The STAR program is administered by the Cal Poly Center for Excellence in Science and Mathematics Education (CESaME) on behalf of the California State University (CSU).