Microorganisms have evolved various life-history strategies to survive fluctuating resource conditions in soils. However, it remains elusive how the life-history strategies of microorganisms influence their processing of organic carbon, which may affect microbial interactions and carbon cycling in soils. Here, ENIGMA researchers characterized the genomic traits, exometabolite profiles, and interactions of soil bacteria representing copiotrophic and oligotrophic strategists. Isolates were selected based on differences in ribosomal RNA operon (rrn) copy number (an established proxy for life-history strategies), with pairs of “high” and “low” rrn copy number isolates represented within the Micrococcales, Corynebacteriales, and Bacillales.
This research advances the understanding of the links between bacterial community composition and the transformation of carbon in soils by connecting bacterial life-history strategies, genomic features, and metabolism.
Researchers found that high rrn isolates consumed a greater diversity and amount of substrates than low rrn isolates in a defined growth medium containing common soil metabolites. High rrn isolates tended to have a greater potential for competitive interactions as predicted using overlap in substrate utilization profiles. Results suggest that resource competition was a major force governing interactions among isolates, while cross-feeding of metabolic secretion likely contributed to the relatively rare positive interactions observed.
Ying Wang, Postdoctoral Researcher
Lawrence Berkeley National Lab
This study is funded by the Genome Sciences Program of the Office of Biological and Environmental Research and by ENIGMA – Ecosystems and Networks Integrated with Genes and Molecular Assemblies (http://enigma.lbl.gov), a Science Focus Area Program at Lawrence Berkeley National Laboratory that is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Biological & Environmental Research.
Wang Y, Wilhelm RC, Swenson TL, Silver A, Andeer PF, Golini A, Kosina SM, Bowen BP, Buckley DH, Northen TR. Substrate Utilization and Competitive Interactions Among Soil Bacteria Vary With Life-History Strategies. Front Microbiol. 2022 Jun 9;13:914472. doi: 10.3389/fmicb.2022.914472. PMID: 35756023; PMCID: PMC9225577.