Comparison of the plant growth-promotion performance of a consortium of Bacilli inoculated as endospores or as vegetative cells

• Published in: FEMS microbiology ecology Vol. 95; no. 11; p. 1
• Main Authors: Hashmi, Isha, Paul, Christophe, Al-Dourobi, Andrej, Sandoz, Frederic, Deschamps, Priscilla, Junier, Thomas, Junier, Pilar, Bindschedler, Saskia
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.11.2019
• Subjects: Bacilli; Bacillus (Bacteria); Consortia; Ecology; Environmental aspects; Germination; Greenhouse effect; Greenhouses; Inoculation; Microbial activity; Microbial colonies; Microbiology; Microorganisms; Physiological aspects; Plant growth; Plant growth promoting substances; Rhizosphere; Seed germination; Seeds; Soil microorganisms; Soil structure; Soils; Strains (organisms); Vegetative cells; Germany; Avena sativa; native microbial communities; Bacillus licheniformis; bacterial consortia; plant growth promotion; Bacillus thuringiensis
• ISSN: 0168-6496; 1574-6941
• DOI: 10.1093/femsec/fiz147

The effect of three plant growth-promoting Bacillus strains inoculated either alone or as a consortium was tested on oat (Avena sativa) growth. The bioinoculants were applied as vegetative cells or endospores at low cell densities on the seeds and their effect was tested in sterile in vitro conditions, pot experiments, and a field trial. The in vitro seed germination assay showed that both individual bacterial inocula and bacterial consortia had positive effects on seed germination. Greenhouse pot experiments with sterile and non-sterile soil showed that consortia increased the total dry biomass of oat plants as compared to single strain inoculation and uninoculated controls. However, the positive impact on plant growth was less prominent when the bioinoculated strains had to compete with native soil microbes. Finally, the field experiment demonstrated that the consortium of vegetative cells was more efficient in promoting oat growth than the endospore consortium and the uninoculated control. Moreover, both consortia successfully colonized the roots and the rhizosphere of oat plants, without modifying the overall structure of the autochthonous soil microbial communities.