Bioformulation of mineral solubilizing microbes as novel microbial consortium for the growth promotion of wheat (Triticum aestivum) under the controlled and natural conditions

Abstract

Microbes are a worthwhile organism of the earth that could be formulated as consortium which can be utilized as biofertilizers. Consortium-based bioinoculants or biofertilizers are superior to single strain-based inoculants for sustainable agricultural productivity and increased micronutrient content in yield. The aim of present study was to evaluate the effect of different combinations of beneficial bacteria that are more effective than single-based bioinoculants. The current work focuses on the isolation of rhizospheric microorganisms from various cereals and pseudocereal crops and the development of a single inoculum as well as a bacterial consortium which were evaluated on wheat crop. A total 214 rhizospheric bacteria were sorted out and, screened for mineral solubilizing attributes i.e., phosphorus, potassium, zinc and selenium solubilization. Among all the bacterial isolates, four potential strains exhibiting P, K, Zn and Se-solubilizing attributes were identified with the help of 16S rRNA gene sequencing as Rahnella aquatilis EU-A3Rb1, Erwinia aphidicola EU-A2RNL1, Brevibacillus brevis EU-C3SK2, and Bacillus mycoides EU-WRSe4, respectively. The identified strains formulated as a consortium which were found to improve the plant growth and physiological parameters in comparison to single culture inoculants and control. To the best of our knowledge, the present investigation is the first report that has developed the consortium from bacterial strains Rahnella aquatilis EU-A3Rb1, Erwinia aphidicola EU-A2RNL1, Brevibacillus brevis EU-C3SK2, and Bacillus mycoides EU-WRSe4. A combination of bacterial strains could be used as liquid inoculants for cereal crops growing in mountainous regions.

Keywords

• Bioformulation
• Consortium
• P- solubilizer
• K-solubilizer
• Zn-solubilizer
• Se-solubilizer