Self-entrapment of plant growth-promoting bacteria in gel matrix and their use as new generation bioinoculants

presentation

English

Azotobacter vinelandii is a rhizobacterium (PGPR), capable of synthezing two completely different biopolymers with great potential for applications. Polyhydroxyalkanoates (PHAs) are produced and stored in the form of intracellular granules, while alginate is produced extracellularly and used for bacterial protection. In agricultural demand, the use of PGPRs as bio-inoculants to increase yields of plants and crops can be an alternative to conventional fertilizers. Encapsulation of bacteria into hydrogel-based carrier substantially improves the application potential of the bioinoculant, as well as the viability and robustness of the bacterium culture. In this work, the extracellularly alginate produced by the bacteria, was cross-linked with a calcium chloride solution (2% w/w) to form a hydrogel carrier with encapsulated bacteria. This unconventional concept, which we termed "self-encapsulation" simplifies encapsulation of bacterial cells and production of hydrogel carriers, leading to the reduction of the costs, an expands its usability in numerous applications. Firt, we screened several strains of A. vinelandii for alginate production and PGPR properties (phytohormone and siderophore production and phosphate solubilization). The strains CCM 289, DSM 87, DSM 13,529 demonstrated the best gelation potential (teste by rheological measurements) and the properties of PGPR. According to our results, the bacteria trapped in a gel matrix seemed to be viable and cultivable, which confirms the feasibility and viability of the novel concept.

Self-encapsulation, PHA, alginate, PGPR, bacteria

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

8. 6. 2023

Milovy, Devět skal

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