Assessing the efficacy of co-inoculation of wheat seedlings with the associative bacteriaPaenibacillus polymyxa1465 andAzospirillum brasilenseSp245

Abstract

Co-inoculation of associative bacteria, which have high nitrogen-fixing activity, tolerance for environmental conditions, and the ability to compete with the natural microflora, is used widely to enhance the growth and yields of agricultural plants. We evaluated the ability of 2 co-inoculated plant-growth-promoting rhizobacteria, Paenibacillus polymyxa 1465 and Azospirillum brasilense Sp245, to colonize roots of wheat (Triticum aestivum L. 'Saratovskaya 29') seedlings, and we assessed the morphometric parameters of wheat early in its development. Analysis by ELISA with polyclonal antibodies raised against the exopolysaccharide of P. polymyxa 1465 and the lipopolysaccharide of A. brasilense Sp245 demonstrated that the root-colonizing activity of A. brasilense was higher when the bacterium was co-inoculated with P. polymyxa than when it was inoculated singly. Immunofluorescence microscopy with Alexa Fluor 532-labeled antibodies revealed sites of attachment of co-inoculated P. polymyxa and A. brasilense and showed that the 2 bacteria colonized similar regions of the roots. Co-inoculation exerted a negative effect on wheat seedling development, inhibiting root length by 17.6%, total root weight by 11%, and total shoot weight by 12%. Under certain conditions, dual inoculation of wheat may prove ineffective, apparently owing to the competition between the rhizobacteria for colonization sites on the plant roots. The findings from this study may aid in developing techniques for mixed bacterial inoculation of cultivated plants.

Paenibacillus polymyxa biofilm polysaccharides antagonise Fusarium graminearum

“…EPS are combinations of monomers and polymers consisting of sugar compounds connected via glyosidic linkages 14,24,25 . EPS length, composition and formation vary considerably 26–28 . The main factors that influence EPS interactions include the charges, polymer functional groups, backbone and chain fitness, and the relative concentrations of the constituents 14,24,25 .…”

Traits-Based Integration of Multi-Species Inoculants Facilitates Shifts of Indigenous Soil Bacterial Community

“…Species integrations are essentially the ratios of microbial species in co-inoculants. The ratios of microbial species in co-inoculants were mostly 1:1 ( Maheshwari et al, 2010 ; Yegorenkova et al, 2016 ). In this study, we set two ratios according to soil fertility, microbial activity and cucumber nutrient requirement.…”

“…Species integrations were essentially the ratios of microbial species in co-inoculants. The ratios of microbial species in co-inoculants were mostly 1:1 ( Maheshwari et al, 2010 ; Yegorenkova et al, 2016 ). Saleem et al (2016) revealed that species richness had positive effects on efficiency and stabilize of microbial co-inoculants and different ratios of a specie had different effects on co-inoculants efficiency.…”

Impact of plant growth-promoting bacteria on grain yield, protein content, and urea-15 N recovery by maize in a Cerrado Oxisol

“…Many in-depth studies have been conducted to improve knowledge on the bacteria-plant association, employing techniques involving genomics, proteomics, and metabolomics (Mukherjee et al 2016;Spaepen and Vanderleyden 2015) as well as co-inoculation (Yegorenkova et al 2016) and the industrial production of inoculants (Bashan and Bashan 2015). However, there is still a lack of information regarding the magnitude and exact mechanisms involved in the positive effects of bacterial inoculants on N nutrition in plants under field conditions, including the role played by PGPB in the recovery of N derived from fertilizer.…”