Next Generation of Bio-inoculants, their Preparation and Viability for the Agricultural Applications

abstract

English

Azotobacter vinelandii is a plant growth-promoting rhizobacterium (PGPR), capable of synthesizing two different biopolymers with great application potential. Polyhydroxyalkanoates (PHAs) are accumulated in a form of intracellular granules, whereas alginate is produced extracellularly. In agricultural demands, the use of PGPRs as bio-inoculants increasing plant and crop yields can be an ecological alternative to conventional fertilizers. To protect bacterial cells and sustain long-term effect of inoculant application, we developed the novel concept in which bacteria are encapsulated into hydrogel-based carriers by using self-produced alginate. In this work, the bacterial culture was crosslinked with a gelation agent (calcium chloride solution) to form a hydrogel carrier with encapsulated bacteria. The produced alginate ranges between 1,67 – 4.9 g/l depending on the strain, whereas the content of PHA varies from 30 to 50% of cdw in all the strains. The stability and strength of the bacterial gels were compared by rheological analysis. Moreover, according to our results the bacteria entrapped in a gel matrix are viable and cultivatable, which confirms the feasibility and viability of the novel concept.

Plant growth-promoting rhizobacteria, PGPRs, alginate, polyhydroxyalkanoates, PHAs, bioinoculants, encapsulation

ČERNAYOVÁ, D.; SEDLÁČEK, P.; SLANINOVÁ, E.; TRUDIČOVÁ, M.; OBRUČA, S.

7. 10. 2022

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