Wetlands harbor lactic acid-driven chain elongators

Journal Article · Tue Dec 12 00:00:00 EST 2023 · Microbiology Spectrum

DOI:https://doi.org/10.1128/spectrum.02105-23· OSTI ID:2229708

Candry, Pieter ^[1]; Flinkstrom, Zachary ^[2]; Winkler, Mari-Karoliina Henriikka ^[2]

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1. University of Washington, Seattle, WA (United States); University of Washington
2. University of Washington, Seattle, WA (United States)

Wetlands are globally significant carbon storage hotspots. Recent research has suggested that microbially derived metabolites may contribute to soil organic matter formation. Identifying pathways driving the formation of such metabolites is critical to understand the global impact of wetland carbon cycling. Here, we evaluate the presence of chain-elongating organisms converting two to three carbon compounds (i.e., lactic and acetic acid) to medium-chain carboxylic acids (MCCA; i.e., six-carbon caproic acid) in wetland soils. We demonstrate the enrichment of a lactic acid-driven chain-elongating community from wetland soils producing a mixture of butyric and caproic acid. The enriched community was dominated by Clostridiaceae, Ruminococcaceae, and Lachnospiraceae, three families with known chain elongators. Amplicon sequencing identified three Ruminococcaceae and one Clostridiaceae zero-radius OTU (zOTU) that were (i) present in the soil, (ii) enriched over 1% relative abundance in the bioreactor, and (iii) were closely related to known chain elongators. Moreover, close relatives of the three Ruminococcaceae zOTU were also observed in several other wetland microbiomes. From this observation, we conclude that close relatives of known chain elongators, potentially capable of lactic acid-driven MCCA production themselves, are present in wetland soils. This observation may have implications for our understanding of carbon cycling and storage in wetland ecosystems.

• Research Organization: University of Washington, Seattle, WA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Biological and Environmental Research (BER)
• Grant/Contract Number: SC0020356
• OSTI ID: 2229708
• Alternate ID(s): OSTI ID: 2229840
• Journal Information: Microbiology Spectrum, Journal Name: Microbiology Spectrum Journal Issue: 1 Vol. 12; ISSN 2165-0497
• Publisher: American Society for Microbiology
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
carbon cycle
chain elongation
medium-chain carboxylic acids
wetland