Correlating enzyme annotations with a large set of microbial growth temperatures reveals metabolic adaptations to growth at diverse temperatures

Abstract

Interpreting genomic data to identify temperature adaptations is challenging due to limited accessibility of growth temperature data. In this work I mine public culture collection websites to obtain growth temperature data for 21,498 organisms. Leveraging this unique dataset I identify 319 enzyme activities that either increase or decrease in abundance with temperature. This is a striking result showing that up to 9% of enzyme activities may represent metabolic changes important for adapting to growth at differing temperatures in microbes. Eight metabolic pathways were statistically enriched for these enzyme activities, further highlighting specific areas of metabolism that may be particularly important for such adaptations. Furthermore, I establish a correlation between 33 domains of unknown function (DUFs) with growth temperature in microbes, four of which (DUF438, DUF1524, DUF1957 and DUF3458_C) were significant in both archaea and bacteria. These DUFs may represent novel, as yet undiscovered, functions relating to temperature adaptation.