Designing of the biological product "Agrobiolog" for mitigating pesticide stress in agricultural plants and stimulating their growth

The results of the selection of new plant growth-promoting bacteria resistant to herbicides of different chemical structure are presented. Two methods were used for screening: sowing on microbiological media from freshly sampled soil and obtaining enrichment cultures from soil samples exposed to herbicides for a month at a temperature of 28 °C. Inoculation was carried out on selective nutrient media containing herbicides Octapon extra (2,5 g/l), Florax (2,5 g/l), Dicamba (1 g/l), Nanomet (1 g/l), Spetsnaz (1 g/l) or Chistalan (2,5 g/l). These herbicides are commonly used to control weeds in wheat crops. The isolated microorganisms belong to the genus Pseudomonas, fix nitrogen, mobilize phosphates, synthesize phytohormones and antimicrobial compounds. They also can mitigate pesticide stress of crops. An anti-stress biological product containing them has been developed and tentatively named "AGROBIOLOG". For its production, the optimal composition of the nutrient medium and the conditions for industrial submerged cultivation on reactors of various volumes were determined. In the laboratory fermenter FA10 with a volume of 10 liters after 72 hours of cultivation at a temperature of 28 °C, a stirrer speed of 200 rpm, aeration of 0.5 volumes of air per 1 min per 1 volume of medium, the amount of viable cells was 28 billion CFU/ml of culture liquid. Cultivation on biological reactors with a volume of 1000 liters under the same conditions allowed to achieve a titer of 6.0 billion CFU/ml of culture liquid.