The paper is concerned with the search for inexpensive alternative components of substrates of culture media for lactic acid bacteria. To be used in the food industry more extensively, lactobacilli should be produced in larger volumes. Bacteria-growing enterprises and those manufacturing probiotic preparations are interested in non-traditional components of growth media. However, it is quite a problem to create a cheap growth medium, because lactobacilli are very demanding of the content of certain components. Traditional culture media can include up to 40 components (peptones, yeast and vegetable extracts, vitamins, etc.). The research has proved that waste and by-products of potato starch production (potato juice and juice-containing water) can be used as components of a substrate to culture lactobacilli on. The strain used in the research was Lactobacillus plantarum 8R-A3. The growth kinetics of lactic acid bacteria has been analysed on different vegetable extracts. Tomato and cabbage extracts were used as traditional components of synthetic media to compare with. The findings have shown that on a substrate from by-products of potato starch production, after 96 hours of culturing at 37°C, the accumulation of Lactobacillus plantarum biomass is 20 g/l (on juice-containing water) and 25 g/l (on potato juice). Accumulation of bacteria wet weight has also been confirmed by determining the kinematic viscosity of the culture fluid. This parameter for potato juice after thermostatting was 6.77 mm2/s, which was somewhat higher than the viscosity of the tomato and cabbage extracts. It has been proved that by-products of potato processing ensure sufficient growth of lactic acid bacteria biomass. On the fourth day, the number of bacteria was 3·108 CFU/cm3. It has been shown how practical it is to use potato processing by-products as growth media substrates in culturing lactic acid bacteria Lactobacillus plantarum.

Subject of research. Biopesticides are based on live cultures of specially selected beneficial microorganisms with controlled properties. They have a pronounced phytoprotective and stimulating effect, thus providing effective prevention and protection of plants from diseases. The obtained biological product increases productivity, improves the quality and structure of the crop, does not accumulate in plants, which allows to obtain environmentally friendly agricultural products and does not harm the environment. Among the large number of bacteria, as a source of microbiological insecticide is Bacillus thuringiensis, which infects lepidopteran pests and leads to their death. Preparations based on this strain are effective when used in low concentrations of solutions. The Bacillus thuringiensis strain produces several toxins with insecticidal action, including β-exotoxin and δ-endotoxin. Toxic effect is manifested and leads to paralysis of the intestinal tract of parasites. Preparations β-exotoxin and δ-endotoxin are obtained by culturing Bacillus thuringiensis bacteria in a liquid medium. The scientific work proposes a method of industrial production using by-products of vegetable raw materials, which makes it economically feasible to use such substrates. The purpose of the study is the development of technology, formulation of nutrient medium, process parameters for the cultivation of bacteria of the genus Bacillus thuringiensis and obtaining a culture fluid containing substances of the class of biopesticides. Methods. Standard and generally accepted methods of research of bioproducts in biotechnology. The formation of bioinsecticides was established by hydrolysis methods, followed by determination of the component of β-exotoxin – ribose, the formation of octagonal crystals of exotoxin – by microscopic method. Research results. Three variants of nutrient media, which include yeast-polysaccharide complex: corn flour, corn oil, yeast autolysate were developed. The parameters of the bacterial cultivation process were studied. The final product is a paste or powder with a titer of 35 .109 spores in 1 g of the bioproduct. Scope of research results. Microbiological preparations based on Bacillus thuringiensis are highly specific and act only on insect larvae from the classes Lepidoptera and Diptera. The resulting biopesticide can be used against pests of a wide range of vegetable and fruit crops.

Various branches of the food and medical industries widely use mushrooms, that is why their aromatic characteristics are quite important. This paper presents a comparative analysis of the aromatic and fatty acid composition of the mycelium of the edible oyster mushroom (Pleurotus ostreatus (Jacq.) P. Kumm., strain K-17) cultured on a glucose-peptone-yeast growth medium with wheat bran added. The quantitative and qualitative composition of the aromas has shown that wheat bran components affect the aroma-forming reactions during the growth of the mycelium of P. ostreatus. It has been established that the introduction of wheat bran increases the content of 1-octen-3-ol, the main fungal aromatic component. In the culture liquid, 1-octen-3-ol increases by 1.4 times, as compared with classic samples cultured on a growth medium without wheat bran. Also, in the mycelium cultured on a wheat bran-containing growth medium, the total quantity of identified aromatic components increases by 1.7 times. In this mycelium, the two main components of the mushroom’s aroma are formed: 1-octen-3-ol and hexanal. In other samples, these important components are absent. The results of this study confirm that the formation of the two main fungal aromatic components, 1‑octen-3-ol and hexanal, involves polyunsaturated fatty acids, namely linoleic acid. Its content decreased in parallel with the accumulation of aromatic components throughout culturing in the wheat bran-containing medium. The data obtained allow establishing how initiation of enzymatic oxidative reactions changes the aroma of P. ostreatus during surface culturing on a liquid medium. The research results reveal the regular patterns in the formation of aromatic components of macromycetes from lipid precursors. Addition of wheat bran to a growth medium unbalances the total content of aromatic components towards their accumulation in the mycelium. Since fruiting bodies and vegetative mycelium are similar in their biochemical composition, the results of studying the mycelium cultured on a liquid medium allow predicting how aromatic components will be formed in the fruiting bodies of oyster mushrooms.