The existence of a correlation between the optimal growth temperature of various organisms and a thermophily index (based on the propensity of amino acids to enter more frequently into the proteins of thermophiles/hyperthermophiles) allows inferences to be made on the mesophilic or thermophilic nature of the last universal common ancestor (LUCA). By reconstructing the ancestral sequences of the various ancestors using methods based on maximum likelihood and maximum parsimony, these sequences can be attributed to the mesophiles or (hyper)thermophiles and the following conclusions can be drawn. (1) There is no evidence that the LUCA might have been a mesophile and observations seem to imply that the LUCA was a thermophile or a hyperthermophile; (2) The ancestors of the Archaea and Bacteria domains seem to be (hyper)thermophiles while that of the Eukarya domain turns out to be a mesophile. These conclusions are independent of both (i) where the root is located on the topology of the universal tree (based on that of the small subunit ribosomal RNA) and (ii) the presence of hyperthermophile bacteria near the node of the Bacteria domain ancestor. These conclusions are easier to interpret in the light of the hypotheses that see the origin of life taking place at a high temperature.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1006/jtbi.2003.3197 | DOI Listing |
Sci Data
January 2025
Chinese Academy of Sciences Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei, 230026, China.
Terrestrial geothermal springs, reminiscent of early Earth conditions, host diverse and abundant populations of Archaea. In this study, we reconstructed 2,949 metagenome-assembled genomes (MAGs) from 152 metagenomes collected over six years from 48 geothermal springs in Tengchong, China. Among these MAGs, 1,431 (49%) were classified as high-quality, while 1,518 (51%) were considered as medium-quality.
View Article and Find Full Text PDFBioresour Technol
January 2025
Institute of Process Equipment and Environmental Engineering, School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110819, China. Electronic address:
Livestock manure is difficult to manage for high moisture and nutrients. High-temperature composting (> 75 °C) reduces moisture. However, the humification process, crucial for nutrient recycling, remains poorly understood.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA.
Thermophilic microbial communities growing in low-oxygen environments often contain early-evolved archaea and bacteria, which hold clues regarding mechanisms of cellular respiration relevant to early life. Here, we conducted replicate metagenomic, metatranscriptomic, microscopic, and geochemical analyses on two hyperthermophilic (82-84 °C) filamentous microbial communities (Conch and Octopus Springs, Yellowstone National Park, WY) to understand the role of oxygen, sulfur, and arsenic in energy conservation and community composition. We report that hyperthermophiles within the Aquificota (Thermocrinis), Pyropristinus (Caldipriscus), and Thermoproteota (Pyrobaculum) are abundant in both communities; however, higher oxygen results in a greater diversity of aerobic heterotrophs.
View Article and Find Full Text PDFGenome Biol Evol
January 2025
Department of Biological Sciences, Dartmouth College, Hanover, NH, USA.
Evolutionary events leading to organismal preference for a specific growth temperature, as well as genes whose products are needed for a proper function at that temperature, are poorly understood. Using 64 bacteria from phylum Thermotogota as a model system, we examined how optimal growth temperature changed throughout Thermotogota history. We inferred that Thermotogota's last common ancestor was a thermophile and that some Thermotogota evolved the mesophilic and hyperthermophilic lifestyles secondarily.
View Article and Find Full Text PDFBioresour Technol
December 2024
Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!