Location
University of Nevada Las Vegas, Student Union Ball Room
Start Date
6-8-2008 9:00 AM
End Date
6-8-2008 12:00 PM
Description
Photosynthesis does not occur above 73°C, so organisms living above this temperature must obtain useable carbon by some other mechanism. It is generally assumed that carbon is fixed by thermophiles through the process of chemolithoautotrophy; however, primary production has never been demonstrated to occur in hot springs >73°C. We have shown that two organisms, Thermocrinis and Pyrobaculum, make up more than 90% of the cells in an 80°C Great Basin hot spring, Great Boiling Spring. We hypothesize that these organisms fix carbon in the hot spring via the reverse tricarboxylic acid (rTCA) cycle. To test this hypothesis we will: i) confirm that Thermocrinis and Pyrobaculum dominate in water from the spring; ii) determine whether key genes for the rTCA cycle, citryl co-A lyase (ccl), 2-oxoglutarate:ferredoxin oxidoreductase (korA), pyruvate:ferredoxin oxidoreductase (porA), are present and expressed in the spring; and iii) measure rates of carbon fixation in the spring. Linkage of the genetic data with carbon fixation rate data may help to provide an image of carbon fixation and cycling in Great Basin hot springs.
Keywords
Carbon fixation; Chemolithoautotrophy; Extremophiles; Genetic analysis; Great Basin; Great Boiling Spring; Hot springs; Nevada; Pyrobaculum; Thermocrinis; Thermophiles
Disciplines
Bacteriology | Genetics
Language
English
Genomic foundations of carbon fixation in bacteria living in hot springs
University of Nevada Las Vegas, Student Union Ball Room
Photosynthesis does not occur above 73°C, so organisms living above this temperature must obtain useable carbon by some other mechanism. It is generally assumed that carbon is fixed by thermophiles through the process of chemolithoautotrophy; however, primary production has never been demonstrated to occur in hot springs >73°C. We have shown that two organisms, Thermocrinis and Pyrobaculum, make up more than 90% of the cells in an 80°C Great Basin hot spring, Great Boiling Spring. We hypothesize that these organisms fix carbon in the hot spring via the reverse tricarboxylic acid (rTCA) cycle. To test this hypothesis we will: i) confirm that Thermocrinis and Pyrobaculum dominate in water from the spring; ii) determine whether key genes for the rTCA cycle, citryl co-A lyase (ccl), 2-oxoglutarate:ferredoxin oxidoreductase (korA), pyruvate:ferredoxin oxidoreductase (porA), are present and expressed in the spring; and iii) measure rates of carbon fixation in the spring. Linkage of the genetic data with carbon fixation rate data may help to provide an image of carbon fixation and cycling in Great Basin hot springs.
Comments
Abstract & poster