Abstract
Aim: Low-molecular-weight organic substances (LMWOSs) are at the nexus between micro-organisms, plant roots, detritus, and the soil mineral matrix. The nominal oxidation state of carbon (NOSC) has been suggested as a potential parameter for modelling microbial uptake rates of LMWOSs and the efficiency of carbon incorporation into new biomass. Methods and Results: In this study, we assessed the role of compound class and oxidation state on uptake kinetics and substrate-specific carbon use efficiency (SUE) during the growth of three model soil micro-organisms, a fungal isolate (Penicillium spinulosum) and two bacterial isolates (Paraburkholderia solitsugae, and Ralstonia pickettii). Isolates were chosen that spanned a growth rate gradient (0.046–0.316 h−1) in media containing 34 common LMWOSs at realistically low initial concentrations (25 μM each). Clustered, co-utilization of LMWOSs occurred for all three organisms. Potential trends (p < 0.05) for early utilization of more oxidized substrates were present for the two bacterial isolates (P. solitsugae and R. pickettii), but high variability (R2 < 0.15) and a small effect of NOSC indicate these relationships are not useful for prediction. The SUEs of selected substrates ranged from 0.16 to 0.99 and there was no observed relationship between NOSC and SUE. Conclusion: Our results do not provide compelling population-level support for NOSC as a predictive tool for either uptake kinetics or the efficiency of use of LMWOS in soil solution. Significance and Impact of the Study: Metabolic strategies of organisms are likely more important than chemical identity in determining LMWOS cycling in soils. Previous community-level observations may be biased towards fast-responding bacterial community members.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1479-1495 |
| Number of pages | 17 |
| Journal | Journal of Applied Microbiology |
| Volume | 133 |
| Issue number | 3 |
| DOIs | |
| State | Published - Sep 2022 |
Funding
Graduate financial support for K.T.C. was provided by the College of Agriculture and Life Sciences at Cornell University. Partial graduate financial support and funding were provided by the Cornell University Program in Cross-Scale Biogeochemistry and Climate, which is supported by NSF-IGERT and the Atkinson Center for a Sustainable Future. Postdoctoral support for A.R.K. was provided by a National Science Foundation CAREER Grant (award # 1653092) awarded to L.A. This work was also supported by the AFRI Education and Workforce Development Program, grant no. 2019-67011-29513 from the U.S. Department of Agriculture, National Institute of Food and Agriculture. We thank Roland Wilhelm, Dan Buckley, and Martínez Research Group members for helpful revisions to the manuscript. Sequencing was performed by the Biotechnology Resource Center (BRC) Genomics Facility at Cornell University (http://www.biotech.cornell.edu/brc/genomics-facility). 1H NMR experiments were performed at the Cornell University NMR facility in the Department of Chemistry and Chemical Biology.
ASJC Scopus subject areas
- Biotechnology
- Applied Microbiology and Biotechnology