Streptomycetes produce a huge variety of bioactive metabolites, including antibiotics, enzyme inhibitors, pesticides and herbicides, which offer promise for applications in agriculture as plant protection and plant growth-promoting products. The aim of this report was to characterize the biological activities of strain Streptomyces sp. P-56, previously isolated from soil as an insecticidal bacterium. The metabolic complex was obtained from liquid culture of Streptomyces sp. P-56 as dried ethanol extract (DEE) and possessed insecticidal activity against vetch aphid (Medoura viciae Buckt.), cotton aphid (Aphis gossypii Glov.), green peach aphid (Myzus persicae Sulz.), pea aphid (Acyrthosiphon pisum Harr.) and crescent-marked lily aphid (Neomyzus circumflexus Buckt.), as well as two-spotted spider mite (Tetranychus urticae). Insecticidal activity was associated with production of nonactin, which was purified and identified using HPLC-MS and crystallographic techniques. Strain Streptomyces sp. P-56 also showed antibacterial and antifungal activity against various phytopathogenic bacteria and fungi (mostly for Clavibacfer michiganense, Alternaria solani and Sclerotinia libertiana), and possessed a set of plant growth-promoting traits, such as auxin production, ACC deaminase and phosphate solubilization. The possibilities for using this strain as a biopesticide producer and/or biocontrol and a plant growth-promoting microorganism are discussed.

To increase the organic potato yield, it is necessary to provide the crop with sufficient nutrients and effective means of biocontrol the diseases. The research goal was to characterize the biorationals’ efficacy to achieve competitive organic potatoes’ yield under various weather conditions. A 4-year trial was carried out in the Leningrad region using Udacha variety potatoes. The tests used liquid forms of new polyfunctional biologicals Kartofin based on highly active Bacillus subtilis I-5-12/23 and organic fertilizer BIAGUM obtained from poultry manure by aerobic fermentation in a closed biofermenter. Significant stimulation in plant growth and development to the flowering phase regardless of the hydrothermal conditions of the growing season was noted. The stimulating effect was determined by the combined use of biorationals pro rata to BIAGUM dose. Kartofin biologicals and BIAGUM almost doubled the potato tubers’ yield compared to the control, regardless of the growing season conditions. At the flowering phase, the biological efficacy in potato fungal diseases incidence and development was near 90% under optimal and 50–75% under drought hydrothermal conditions. At the end of vegetation, the efficiency in fungal diseases incidence and development made up 45–65% under optimal and 45–70% under dry conditions. BIAGUM effectiveness in reducing disease development reached 45–50% regardless of growing season conditions.

This study presents data on the biological activity of strain Streptomyces sp. VIZR-018, isolated from Crimean soil, against plant pathogens and phytophagous insects under laboratory and field conditions in the Stavropol region. The strain exhibited high antagonistic activity against a broad spectrum of phytopathogenic fungi and bacteria, insecticidal activity against a group of sucking arthropods, and phytoregulatory activity towards potato, cucumber, wheat, and barley plants. In field trials, pre-planting tuber treatment followed by two applications of a liquid formulation during the potato growing season had a stimulating effect on plant height (+64–71%), stem count (+30–33%), and the onset of flowering. The biological efficacy of the preparation against late blight development, compared to the farm’s standard protection system, ranged from 44.7 to 65.3%. As a result of treatment with the liquid Streptomyces sp. VIZR-018 sample, potato yield increased by 0.8–6.3 t/ha, equivalent to 9–68% compared to the control. In the laboratory, the strain demonstrated high insecticidal activity against the vetch aphid (Megoura viciae), with 100% mortality observed 4 h after treatment with the liquid sample.

The article presents the results of a study of the biological effectiveness of 2 biological drugs in the Leningrad region. This is a biological product Iriard, L. based on Streptomyces loidenis strain P-56 - against wireworms and a drug based on the strain - Streptomyces sp. 0952 (hereinafter referred to as 0952). Strains for new biological products were discovered by colleagues as a result of multi-stage screening based on entomocidal and antifeedant activity. Monoclonal isolates were isolated, based on of which samples of the cultural liquid were formed. In 2022-2023, employees of the FGBI VIZR conducted laboratory and finely differentiated field experiments on the effectiveness of laboratory new samples of biological products based on actinomycetes of the Streptomyces type. The experiments are aimed at expanding the insufficient range of new biological products for protection against the most dangerous pests for this crop: wireworms and the Colorado potato beetle. Application of the drug of Iriard, L. was presented for processing the tubers of the «Nevsky» tubers before planting. Based on the field assessment, it was established that the biological product Iriard, L. reduces the number of wireworms increased, since the number of intact tubers was twice as large as in the control. Another drug based on strain 0952 demonstrated the same biological effectiveness against younger Colorado potato beetle larvae. As a result of treatment of these variants with a biological preparation, 80% - 92% of larvae of 1-2 instars died after 5 days. The dependence of entomocidal and antifidant activity on the concentration of the drug has been established. The use of research drugs to protect against these harmful factors has been experimentally proven.

Organofluorine derivatives of β-D-ribofuranoside were synthesized. Biological tests revealed low toxicity and high insecticidal activity of the obtained compounds.