Elements of the laboratory regimen for production of microbiopreparation in form of ‘wettable powder' based on bacteria-antagonists of a genus Pseudomonas under surface cultivation on liquid nutrient medium

There were developed the elements of the laboratory regimen for production of microbiopreparation in the form of ‘wettable powder' on surface cultivation on liquid nutrient mediums of perspective bacteria strain-producer Sgrc-1 Pseudomonas fluorescens from a collection of the laboratory of biomethods. Period of 5 days was determined as optimal for surface cultivation on a liquid nutrient medium of King B. Optimal ratio between volumes of culture and nutrient medium was 2.0%. Test samples of microbiopreparation in the form of ‘wettable powder' obtained on surface cultivation of the strain Sgrc-1 Pseudomonas fluorescens on a liquid nutrient medium formed a stable suspension in water and had an initial titer 108-9 CFU/g and a moisture content of 6.0-6.8 %. When storing a ‘wettable powder' microbiopreparation in packages with air access and in jars with a tightly closed lid, regardless of the method of biomass separation, under conditions of permanent low temperature (-18 °С), the titer have not decreased within twelve months. When storing under variable temperature in the laboratory room (+24…+26 °С), regardless of the packaging and method of biomass separation, during the twelve months of storage, the titer decreased by four orders of magnitude (105 CFU/g), and under permanent high temperature (+30 °С) - by five to six orders of magnitude (104-3 CFU/g). To preserve test samples of a ‘wettable powder' microbiopreparation based on bacteria of a genus Pseudomonas in packages with air access, under a temperature of +24…+26 °С, during twelve months with an insignificant decrease of titer within the order of magnitude, it is necessary to add one of the antiaging agents: thiourea, hydroquinone, ascorbic acid or sodium humate.