Protein Fragments ID Two New 'Extremophile' Microbes--and May Help Find Alien Life
Published:23 May2024    Source:American Chemical Society
In ACS' Journal of Proteome Research, researchers detail a method for more accurate extremophile identification based on protein fragments instead of genetic material. The study identified two new hardy bacteria from high-altitude lakes in Chile -- an environment like early Mars.
From the samples, the researchers cultivated 66 microbes and then determined which of two methods better identified the microorganisms: Traditional gene sequencing compared the nucleotides of the 16s rRNA gene (a typical gene for sequence-based microbe analysis) from each sample to a database for identification. The newer "proteotyping" technique analyzed protein fragments known as peptides to produce peptide signatures, which the team used to identify microorganisms from proteome databases.

With these methods, the researchers identified 63 of the 66 microorganisms that were cultivated from the high-altitude lake samples. For the three microorganisms that gene sequencing failed to identify because their genetic information wasn't in the available database, proteotyping identified two potentially new types of extremophile bacteria. These results suggest proteotyping could be a more complete solution for identifying extremophile microorganisms from small biological samples.