Choosing source of microorganisms and processing technology for next generation beet bioinoculant

Area of Science:

• Agricultural Science
• Microbiology
• Biotechnology

Background:

• Increasing agricultural demands due to population growth lead to soil over-exploitation.
• Biofertilizers utilizing lyophilized plant material with plant growth-promoting microorganisms (PGPM) offer a sustainable alternative to conventional fertilizers.
• Understanding endophytic microbiome diversity and factors influencing its resilience is crucial for developing effective biofertilizers.

Purpose of the Study:

• To assess the diversity of endophytic bacteria within sugar beet and sea beet roots.
• To investigate the impact of osmoprotectants (trehalose and ectoine) during lyophilization on bacterial density, viability, and salt tolerance.
• To evaluate the potential of these bacteria for use in improved biofertilizer formulations.

Main Methods:

• 16S rRNA amplicon sequencing was used to analyze microbiome diversity.
• Bacterial density and salt tolerance were evaluated through microbial cultures.
• Bacterial viability was quantified using fluorescence microscopy and flow cytometry.

Main Results:

• Plant genotype significantly influences endophytic microbiome diversity and soil properties.
• Sea beet harbors a more diverse and salt-resistant endophytic microbiome compared to sugar beet, with genera adapted to extreme environments.
• Incorporating osmoprotectants during lyophilization positively impacts bacterial community salt stress tolerance, viability, and density.
• Trehalose demonstrated superior efficacy over ectoine in enhancing these parameters and offers economic advantages.

Conclusions:

• Endophytic microbiome composition is strongly influenced by plant genotype.
• Sea beet exhibits a more robust endophytic microbiome suited for saline conditions.
• Osmoprotectants, particularly trehalose, are effective in preserving and enhancing the functionality of PGPM during biofertilizer production, paving the way for more resilient and effective biofertilizers.