Microbial community composition and glyphosate degraders of two soils under the influence of temperature, total organic carbon and pH

Angelica M. Muskus, Anja Miltner, Ute Hamer, Karolina M. Nowak

    Research output: Contribution to journalArticlepeer-review

    3 Scopus citations

    Abstract

    Glyphosate can be degraded by soil microorganisms rapidly and is impacted by temperature and soil properties. Enhanced temperature and total organic carbon (TOC) as well as reduced pH increased the rate of 13C315N-glyphosate conversion to CO2 and biogenic non-extractable residues (bioNERs) in a Haplic Chernozem (Muskus et al., 2019) and in a Humic Cambisol (Muskus et al., 2020). To date; however, the combined effect of temperature and TOC or pH on microbial community composition and glyphosate degraders in these two soils has not been investigated. Phospholipid fatty acid [PLFA] biomarker analysis combined with 13C labeling was employed to investigate the effect of two soil properties (pH, TOC) and of three temperatures (10 °C, 20 °C, 30 °C) on soil microorganisms. Before incubation, the properties of a Haplic Chernozem and a Humic Cambisol were adjusted to obtain five treatments: (a) Control (Haplic Chernozem: 2.1% TOC and pH 6.6; Humic Cambisol: 3% TOC and pH 7.0), (b) 3% TOC (Haplic Chernozem) or 4% TOC (Humic Cambisol), (c) 4% TOC (Haplic Chernozem) or 5% TOC (Humic Cambisol), (d) pH 6.0 (Haplic Chernozem) or pH 6.5 (Humic Cambisol), and (e) pH 5.5 for both soils. All treatments were amended with 50 mg kg−1 glyphosate and incubated at 10 °C, 20 °C or 30 °C. We observed an increase in respiration, microbial biomass and glyphosate mineralization with incubation temperature. Although respiration and microbial biomass in the Humic Cambisol was higher, the microorganisms in the Haplic Chernozem were more active in glyphosate degradation. Increased TOC shifted the microbiome and the 13C-glyphosate degraders towards Gram-positive bacteria in both soils. However, the abundance of 13C-PLFAs indicative for the starvation of Gram-negative bacteria increased with increasing TOC or decreasing pH at higher temperatures. Gram-negative bacteria thus may have been involved in earlier stages of glyphosate degradation.

    Original languageEnglish
    Article number118790
    JournalEnvironmental Pollution
    Volume297
    DOIs
    StatePublished - 15 Mar 2022

    Bibliographical note

    Funding Information:
    The authors thank the Helmholtz Centre for Environmental Research - UFZ and the German Research Council (DFG. No 980/1-3 ) for supporting the research. COLCIENCIAS Foundation is acknowledged for funding the fellowship of A. Muskus. We also appreciate the valuable assistance of Ursula Günther, Steffen Kümmel and Matthias Gehre (UFZ. Dept. Isotope Biogeochemistry) in compound-specific isotope analysis. We also thank the DAAD-RISE students Charles Cole and Tiange Yuan for their assistance with measuring the samples and the DAAD for the financial support of their stay at UFZ.

    Funding Information:
    The authors thank the Helmholtz Centre for Environmental Research - UFZ and the German Research Council (DFG. No 980/1-3) for supporting the research. COLCIENCIAS Foundation is acknowledged for funding the fellowship of A. Muskus. We also appreciate the valuable assistance of Ursula G?nther, Steffen K?mmel and Matthias Gehre (UFZ. Dept. Isotope Biogeochemistry) in compound-specific isotope analysis. We also thank the DAAD-RISE students Charles Cole and Tiange Yuan for their assistance with measuring the samples and the DAAD for the financial support of their stay at UFZ.

    Publisher Copyright:
    © 2022

    Keywords

    • Glyphosate
    • Mineralization
    • pH
    • PLFAs
    • Soil respiration
    • TOC

    Fingerprint

    Dive into the research topics of 'Microbial community composition and glyphosate degraders of two soils under the influence of temperature, total organic carbon and pH'. Together they form a unique fingerprint.

    Cite this