Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Jul;84(1):106-121.
doi: 10.1007/s00248-021-01837-1. Epub 2021 Aug 17.

Plant Growth Promoting Bacterial Consortium Induces Shifts in Indigenous Soil Bacterial Communities and Controls Listeria monocytogenes in Rhizospheres of Cajanus cajan and Festuca arundinacea

Richa Sharma  1 , Laurent Gal  2 , Dominique Garmyn  2 , David Bru  2 , Shilpi Sharma  1 , Pascal Piveteau  3   4
Affiliations

Plant Growth Promoting Bacterial Consortium Induces Shifts in Indigenous Soil Bacterial Communities and Controls Listeria monocytogenes in Rhizospheres of Cajanus cajan and Festuca arundinacea

Richa Sharma et al. Microb Ecol. 2022 Jul.

Abstract

The rhizosphere is a dynamic and complex interface between plant roots and microorganisms. Owing to exudates, a web of interactions establishes among the microbial members of this micro-environment. The present study explored the impact of a bacterial consortium (Azotobacter chroococcum, Bacillus megaterium and Pseudomonas fluorescens, ABP), on the fate of a human pathogen, Listeria monocytogenes EGD-e, in soil and in the rhizospheres of Cajanus cajan and Festuca arundinacea, in addition to its plant growth promoting effect. The study further assessed the impact these bioinoculants exert on the autochthonous soil bacterial communities. Experiments in sterilised soil inoculated with bioinoculants and L. monocytogenes revealed the inhibition of L. monocytogenes by approximately 80-fold compared to that without the consortium. Subsequently, experiments were conducted in non-sterile soil microcosms planted with C. cajan and F. arundinacea, and in bulk soil. The consortium led to a significant increase in plant growth in both plants and prevented growth of L. monocytogenes. However, the presence of resident soil bacterial communities overshadowed this inhibitory effect, and a sharp decline in L. monocytogenes populations (5-6 log reduction) was recorded under non-sterile soil conditions. A shift in the soil resident bacterial communities was observed upon amendment with the bioinoculants. A significant increase of potential Plant Growth Promoting Rhizobacteria (PGPR) and biocontrol agents was observed, while the abundance of potential phytopathogens dropped. The present study opens up new avenues for the application of such a consortium given their dual benefits of plant growth promotion and restricting phytopathogens as well as human pathogen.

Keywords: Azotobacter chroococcum; Bacillus megaterium; Biocontrol; Inhibition; Listeria monocytogenes; Microbial diversity; Pseudomonas fluorescens; Rhizosphere.

PubMed Disclaimer

References

    1. Vig K, Singh DK, Agarwal HC, Dhawan AK, Dureja P (2008) Soil microorganisms in cotton fields sequentially treated with insecticides. Ecotoxicol Environ Saf 69:263–276 - PubMed
    1. Hinsinger P, Bengough AG, Vetterlein D, Young IM (2009) Rhizosphere: biophysics, biogeochemistry and ecological relevance. Plant Soil 321:117–152
    1. Schreiter S, Ding G, Heuer H, Neumann G, Sandmann M, Grosch R, Kropf S, Smalla K (2014) Effect of the soil-type on the microbiome in the rhizosphere of field-grown lettuce. Front Microbiol 5:1–13
    1. Mendes A, Garbeva P, Raaijmakers JM (2013) The rhizosphere microbiome: significance of plant beneficial, plant pathogenic, and human pathogenic microorganisms. FEMS Microbiol Rev 37:634–663 - PubMed
    1. Mahmood S, Rehman Y, Hasnain S (2015) Cross-kingdom pathogenicity across plants and human beings. J Bacteriol Parasitol 6:e124