ENTOMOPATHOGENIC BACILLUS THURINGIENSIS TO ISOLATE BACTERIAL STRAINS AND APPLY THEM AGAINST GREENHOUSE MITES

Аннотация

The article presents experimental data on methods for isolating Bacillus thuringiensis bacterial strains from dead greenhouse aphids and soil, and on the use of different concentrations against greenhouse aphids that damage tomato plants. Keywords: Bacillus thuringiensis, bacteria, strain, culture medium, tomato, pest, greenhouse aphid, nutrient medium, entomopathogen, soil. Introduction. The eve of the 21st century is characterized byan unprecedented scale of conscious use of microorganisms in agricultural production. In all areas of the agro-industrial complex, the need for the use of microorganisms and their metabolites was recognized, and, accordingly, the development and use of biopreparations for the needs of Plant Science, Livestock, Veterinary andfeed production is being established. There is also an increasing need for microbial preparations in the field of protecting plants and agricultural animals from pests and parasites. As a competitor to the chemical means of controlling insects, rodents and phytopathogens, biopesticide is becoming an attribute of advanced agricultural systems. The need for them is associated with the size of man-made loads on the environment, the inefficiency of chemical pesticides, the risk of toxic, allergic and even genetic adverse effects with their widespread use and the development of resistance in pests, the elimination of natural mechanisms for regulating their number and, finally, the pollution of landscapes, water resources and food products. Scientific sources know that in later times the microbiological method of combating insects is widely used in the agrarian industry. Therefore, the production of environmentally friendly microbial pesticidebiopreparations is ofgreat scientifictheoretical and practical importance. Research methods. The distribution of the main pests of tomato and cucumber plants in the greenhouse was examined by taking samples diagonally or chess. In the course of the survey, samples ofpest insects that had died were collected insterilized paper bags, which were prepared inadvance. Each samplewas stored in refrigerators untilit was examined in thelaboratory. In order to extract entomopathogenic fungi from pests of tomato and cucumber plants, insect specimens that died due to the disease were cleaned of microorganisms, that is, their outer part was sterilized. The pest samples that were being tested were soaked in a 0.5-1% sodium hypochloride (NaOCl) solution for 30 seconds and thoroughly washed out of the solution and rinsed once again in another container of sterilized water, then the pest samples were picked up in front of an alcohol lamp flame on the surface of a solid food medium placed on sterilized Petri https://ijmri.de/index.php/jmsi volume 4,issue3,2025 821 saucers. Each specimen was placed in a separate petri saucer with a pest sample of 10-15 pieces. Petri was stored in thermostats with a temperature of 24-260 C. The growth of bacteia in petri lycobchas was observed for 15 days from the third day. Then the fungal mycelium grown from the specimens planted in the artificial food environment in Petri's saucers was planted in test tubes with a sterilized microbiological loop in front of an alcohol lamp flame. In order to extract disease-causing bacteria from insects, the composition was used from different food environments (Agar Chapek, agaric beer suslosi, agaric potatoes). The pure culture of the bacteias was assigned tothesolid foodenvironments in thetest tubes. To isolate the isolates of Bacillus thuringiensis, extinct effluent samples collected from the field were used. Bacterial extraction was conducted according to the method described by Gonzalez et al (2011). The collected effluents were previously crushed in an 80 oC water bath for 10 minutes to kill vegetative cells and non-spore-forming bacteria. This ground oocyanote was then grown in a GPA nutrient medium. Colonies similar to those of Bacillus have been isolated and examined for the presence of papasporal crystals. Then B.thuringiensis colonies were identified and isolated. Here are 3 B.isolated thuringiensis isolates (BTE-1, bte-2, bte-3). They were found todiffer from each otherin crystal shapeand morphology oftheircolony. Also isolated from the soil were the isolates Bacillus thuringiensis. To do this, 2-3 cm of the top layer was removed. Then a 20 gr soil sample was placed in special bags. The special bags were kept at 4 oC until laboratory work began. To extract bacteria from soil samples, Song et al. (2008) through the method described. 1g of soil sample 10ml 0.85% NaCl was suspended. Then heated in a vibrating thermostat at 70 °C for 10 minutes. The nutrient agar (0.5% pepton, 0.3% beef extract, 0.5% NaCl and 1.5% agar) was suspended for 100 µl. This used 50 petri dishes, all incubated at 30±2 °C for 48 hours. Bacterial colonies showing a phenotype similar to Bacillus thuringiensis were isolated and moved to a new food environment. These colonies were reared a secon