Extremely rapid bacterial growth rates at Lake Tanganyika’s hydrothermal vents
Ann Arbor, MI — Bacteria with doubling times as short as 10 minutes have been discovered in areas of hot water emissions in Lake Tanganyika.
Small chimneys emitting hot water at temperatures of 66 to 103 degrees Celsius (150 to 217 degrees Fahrenheit) have been discovered at the shallow lake bottom of Lake Tanganyika, East Africa. In a study searching for thermophilic sulfate reducing bacteria in this extreme environment, a spore-forming bacterium was discovered that grew with a doubling time as short as 10 minutes. In theory, a single cell of this bacterium in this environment can multiply to 500 million in less than 5 hours under optimal conditions (60 degrees Celcius). Further, as the bacterium was found to form heat resistant endospores, it may be able to survive outside of the observed growth temperatures (40 to 75 degrees Celcius) and spread to other active vent sites. The bacterium therefore, could rapidly establish itself under varying environmental growth conditions.
"The growth rates of our isolated bacterium are among the fastest ever recorded," says Lars Elsgaard, a Senior Scientist at the Aarhus University in Denmark and principle investigator of this study. "In the hydrothermal environment, temperatures may fluctuate and only temporarily be optimal for the growth of thermophilic microorganisms. The present bacterium seems well adapted to take advantage of such changing environmental conditions."
The bacterium found in this study belongs to a group of organisms living without oxygen and at high temperatures. The discovered bacterium with its fast and resilient growth rate may be ecologically important in the mineralization of organic carbon at the hydrothermal environment of Lake Tanganyika. Thus, the bacterium has the capacity to initiate the breakdown of complex substrates to smaller molecules that can subsequently be completely degraded by other microorganisms.
Original Publication Information
Results of this study, "Hydrothermal vents in Lake Tanganyika harbor spore-forming thermophiles with extremely rapid growth," are reported by Lars Elsgaard and Daniel Prieur in the latest issue (Volume 37, No. 1, pp. 203-206) of the Journal of Great Lakes Research, published by Elsevier, 2011.
Contacts
For more information about the study, contact Lars Elsgaard, Senior Scientist with the Faculty of Science and Technology, Aarhus University, Blichers Alle 20, DK-8839 Tjele, Denmark; Lars.Elsgaard@agrsci.dk; +45 8999 1873.
For information about the Journal of Great Lakes Research, contact Marlene Evans, Editor, National Water Research Institute, Environment Canada, 11 Innovation Boulevard, Saskatoon, SK, S7N 3H5, Canada; jglr@ec.gc.ca; (306) 975-5310.
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