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Researchers Estimate Maximum Growth Rate for Life on Earth

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Research presented at the Astrobiology Science Conference in Arizona has challenged assumptions about how microbes behave at high temperatures.

It’s common knowledge that microbes grow at a faster rate at higher temperatures, such as the everyday example of milk going “off” when it’s left out of the fridge. However, Dr Ross Corkrey’s laboratory at The University of Tasmania last year discovered that the maximum rate of microbial growth plummets dramatically once temperatures reached somewhere above 40°C. This distribution of growth rates was termed the Biokinetic Spectrum for Temperature (BKST).

Building on this work, the team has now quantified the data and provided an estimate on the maximum growth rate for life on Earth. “We now find that the predicted maximum growth rate occurs at 45.8°C, with an estimated minimum generation time of 5.16 minutes. This means that the shortest possible time in which a cell can divide to make two daughter cells is a little more than 5 minutes,” Corkrey said. “We are now considering how this limit may influence ecological processes that vary by temperature, including, perhaps, those of marine plankton.”

To arrive at the numbers, the team collated more than 10,000 measurements of growth rates representing 1627 microbe strains. “We mathematically modelled them to obtain the predicted maximum rate of growth versus...

The full text of this article can be purchased from Informit.