Talmudic Question #37

by Rob Edwards

What's the lowest temperature at which microbes can grow? Clearly it is below 0°C and above − 273°C, so we have a range. See a review on the topic.

Likewise, what's the hottest temperature for growth?

Comments

[Peter Bergholz]

In terms of the lower temperature limits, the eutectic point of water is -40C. Several recent studies have looked at metabolics and gene expression as low as -15C. There are groups experimenting with bacteria in vitrious ice (ice as a glass) down to -187C. In terms of growth rates, we see aerobic heterotrophs doubling every few days in rich media down to -6C and every couple weeks in mineral media with a single C-source.

[elio]

Mike,

Many thanks for pointing out the current Olympic champ. The article is at
http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=18664583

The race is surely on.

Elio

[Mike Gray]

I'll add my vote to Christopher's; as long as you've got liquid water, at either end of the spectrum, something should be able to eke out a living. Is there some physical limit to how low you can get the freezing temperature of water by adding solutes?

There was a recent PNAS paper describing a method for growing Methanopyrus kandleri at 122° under pressure, so strain 121 has been beaten, but not by much...

[Rhea Miller]

I'd agree with Christopher.

And for always giving me a moment to reflect on our lil bugs...i have tagged this blog on mine for an award.

[Christopher Taylor]

As far as I know (and I suspect you know know this too), the highest growth temperature recorded to date is 121 degrees C for Strain 121 - but it has a ridiculously slow growth speed of about one day's doubling time. Personally, I wouldn't be at all surprised if some life form could handle almost any temperature so long as there was enough pressure to maintain liquid water.