Bacillus megaterium B-4801 Strain Efficiency in Growing Cereal Crops in Conditions Representative of Russia's Non-Chernozem Zone.

Abstract

Background: This study evaluates the possibility of using the experimental preparation "Naturost-M" based on the Bacillus megaterium B-4801 strain in crop production in conditions representative of Russia's non-Chernozem zone. The research objectives included whole genome sequencing of the B-4801 strain to determine its biotechnological potential and to study the effect of the preparation on the growth and grain productivity of several cereal crops.

Methods: Whole genome sequencing of the B. megaterium B-4801 strain was performed at the Biotroph molecular genetic laboratory using the MiSeq platform (Illumina, Inc.). We conducted studies using cereal crops (barley, oats, and wheat) during the 2019-2022 growing seasons at the Vologda Research Center of the Russian Academy of Sciences experimental field. The preparation "Naturost-M" was applied twice: soaking seeds and spraying the phyllosphere of plants in the tillering phase. The raw and dry weights of experimental and control plants were measured in the tillering and earing phases during the growing season. We evaluated grain productivity at the end of the growing season.

Results: Whole genome sequencing of the B. megaterium B-4801 strain revealed the main components of antimicrobial compound biosynthesis pathways, including a cluster of genes responsible for synthesizing enzymes for forming aliphatic unsaturated carboxylic acids containing 3-18 carbon atoms. Our research identified genetic loci encoding the synthesis of bacteriocins such as canosamine and polyketide ansamycin bacteriocins. The genome of the studied strain included clusters responsible for the biosynthesis of secondary metabolites such as siderophores and lantipeptides, as well as a whole range of genes responsible for various adaptation mechanisms of the strain to environmental conditions. Treatment of cereal crops with the experimental preparation "Naturost-M" contributed to an increase in growth parameters: raw weight was increased to 67% compared to the control, dry weight was up to 79% (depending on the year of study, phase of ontogenesis and culture), which occurred against the background of an increase in the content of photosynthetic pigments. Grain productivity grew in barley by 7-46%, oats by 12-31%, and wheat by 5-11% under conditions of small-plot experiments when using the preparation.

Conclusions: The B. megaterium B-4801 strain has a certain biotechnological potential for crop production practice; experimental preparation created on its basis showed a stimulating effect on the growth and productivity of grain crops in conditions representative of Russia's non-Chernozem zone.