RU2160005C2 - Method of preparing insecticide agent based on bacillus thuringiensis - Google Patents

Abstract

FIELD: biotechnology. SUBSTANCE: sodium chloride, carbon black, and coniferous odorant are added to culture broth containing spore-crystal complex of Bacillus thuringiensis and a part of sulfite-alcohol distillery dregs. Mixture is agitated and partially dried to give double-layered preparation with its shell consisting of dregs (85-90% of tits total quantity) and internal part comprising the rest of dregs and other ingredient. Preparation shows activity against coleopterous insects. EFFECT: increased stability on storage. 2 ex

Description

 The invention relates to the field of biotechnology, and in particular to methods for producing bioinsecticidal preparations against Coleoptera, in particular against the Colorado potato beetle.

 Nowadays, drugs based on you are mainly used against the Colorado potato beetle. thuringiensis (BT) (Slavnova BC, Kavychina LI, Shevtsov PP Bacterial insecticides based on Bacillus thuringiensis in an integrated plant protection system.- M .: All-Russian Research Institute of SENTI, 1985, 31 pp .; Specifications “Dry Bitoxibacillin” TU 64-15-01-85).

 In particular, the drug Bitoxibacillin is known, which is a mixture of a 50-70% sporocrystalline complex of VT with residues of a nutrient medium (SCS VT) and a kaolin filler. The latter is introduced into the nutrient medium in an amount of 30-50% based on the final product (Specifications "Bitoxibacillin dry". TU 64-15-01-85).

 The disadvantage of the drug is rapid sedimentation, which does not allow to achieve a uniform distribution of the insecticide on the treated surface.

 The closest analogue of the claimed invention is a method for the production of BT-based insecticidal preparation created with the participation of the author (Laid-open patent application of the Russian Federation N 94026138, 1996, class A 01 N 63/00), which consists in mixing together parts of the ingredients, namely, containing SCS BT with additives of such substances as perfumes, photoprotectors, antioxidants, wetting agents, adhesives, etc., as well as part (10-15 wt.% Of the regulated amount) of sulphite-alcohol stillage (PRS).

 The preparation was mixed, dried, after which additional amounts of previously dried PRS were introduced as a filler to match its activity with GOST.

The resulting preparation had increased activity compared to its counterparts in relation to the Colorado potato beetle, but had a rather limited shelf life of not more than 1.5 years at a temperature of from -30 to +30 ^o C. During this period, the drug loses up to 70% of spore activity, while maintaining total activity about 1500 EA / mg.

 The problem solved in the framework of the present invention was the creation of a method of obtaining a more stable during storage of the drug. Moreover, the task was complicated by the fact that, in accordance with regulatory requirements, the authors did not have the right to change the active principle and the main composition of the drug.

 The solution to this problem was to create a technology for the preparation of the drug, in which the PRS introduced into the final product would perform protective functions to protect the active principle from the effects of negative environmental factors.

 In the course of solving this problem, it was possible to obtain a “two-layer” preparation, the shell of which consists of stillage, constituting 85-90 wt.% Of the prescribed amount (25-40% wt.% In the total composition of the drug), and the inside of the mixture of the remaining amount SB with SCS BT, and the aforementioned substances that perform auxiliary functions, the introduction of which into the composition serves to solve individual particular problems.

 As such substances photoprotectors are used, for example, charcoal, soot, molasses, lignin sulfonate, etc .; antioxidants: rizorcin, thiourea, hydroquinone, etc .; wetting agents: twins, neonol, AF-9, oleic acid and others; as well as adhesives such as milk powder, polyvinyl acetate, etc. (the content of individual substances is from 0.1 to 4%).

 To solve this problem, SB is introduced into the composition in two parts. One part, comprising 10-15 wt.% Of the regulatory amount, is introduced into the SCS BT concentrate simultaneously with other components, ensuring the formation of a uniform spatial structure, and the rest is introduced after the mixing stage, ensuring the appearance of a “shell” of the above structure.

 The second part of CERs, depending on the composition of the ingredients, can be introduced either after partial drying, or directly into the mixture obtained in the first stage. In this case, the solvent contained in the system, wetting the SSB, ensures its fixation on the surface of the "core", forming a shell on the spatial structure that is formed at the first stage.

 Moreover, the identity of the shell material and the internal “network” of SDB, on the nodes of which particles of other components are placed in a half-dissolved state, and bacterial spores, allows them to provide an additional slightly improved diffusion of the active principle onto the surface of the droplet after spraying the drug.

 The following examples illustrate the essence of the sentence in more detail.

Example 1. In a concentrate of a culture fluid containing sporocrystalline complex of you. thuringiensis var. SSP thuringiensis and residues of the nutrient medium contribute the remaining components with part of the PRS. The concentrate (in an amount of 17 m ³ ) had a content of absolutely dry substances (ASV) of 4.4%, which is 751 kg. 6.0 kg (0.7%) of sodium chloride, 2.2 kg (0.3%) of carbon black, 22.5 l (3.0%), coniferous fragrance, 22 kg of PRS (3%) are added to this amount of concentrate. ) The resulting mixture is thoroughly mixed and pumped for spray drying.

 The exotoxin content was found to be 0.98% in the product, then an additional 218 kg of dried sulphite-alcohol stillage were added and the mixture was mixed again. As a result, 1040 kg of a finished standardized product with a moisture content of 3.3%, spore titer of 50 billion spores / g, biological activity of 2600 EA / mg, wettability of 80 s, stability of a 1% working suspension of 76%, exotoxin content 0, 75%, the smell is light coniferous.

 The preparation was a mixture of particles with a size of 90-130 microns. Electron microscopy data of the slice of the particle of the preparation showed that the preparation consists of an internal friable part, which makes up about 50% of the area of the cut, and an external denser shell. The fraction does not contain particles with a diameter of more than 200 microns.

 Tests of the drug, which received the code name “Baksin,” in the field on potato plantations against Colorado potato beetle larvae of 1-2 ages showed that with a drug consumption of 1 kg / ha, the larval death is 95%.

 The well-known drug Bitoxinbacillin at a rate of 3 kg / ha ensures the death of 76% of the larvae. The preparation is a fraction of particles with sizes from 80 to 600 microns, in which the fraction of 500-600 microns was 0.3%, and the fraction of 150-500 microns was 24%. Electron microscopy data of a slice of a drug particle showed that the drug consists of a homogeneous structure.

When stored in the temperature range from -30 to +30 ^o C for 2 years, the drug lost about 30% of the activity of the spores, while maintaining activity of about 2000 EA / mg.

 Ppimer 2. Into a concentrate of a culture fluid containing a sporocrystalline complex of you. thuringiensis. sp thuringiensis and the remains of the nutrient medium, contribute the remaining components and part of the PRS. The concentrate (in the amount of 2500 l) had a content of absolutely dry substances (ASV) of 8.0%, which is 200 kg. 10 kg (5.0%) of sodium chloride, 6.0 l (3.0%) of neonol, 9.0 kg (5.0%) of dry sulphite-yeast stillage and 4.0 l (2) were added to this amount of concentrate , 0%) solution of attractants. The resulting mixture was thoroughly mixed.

 The exotoxin content was found to be 0.97% in the finished product, then 51.0 kg of dried sulphite-yeast stillage were added and the mixture was mixed again. The result was 250.6 kg of a finished standardized product, named Bicol and having a moisture content of 4.1%, spore titer of 50.7 billion spores / g, biological activity of 2612 EA / mg, wettability of 90 s, stability of the working suspension of 70%, the content of exotoxin is 0.75%, the smell is light pleasant.

 The drug was a mixture of particles with a size of 80-150 microns. Electron microscopy data of a slice of a particle of a preparation showed that the preparation consists of an internal, more friable part, which constitutes about 60% of the area of the cut, and an external denser shell. The fraction does not contain particles with a diameter of more than 200 microns.

Field tests of the drug in apple orchards against codling moths and leafworms showed that with a drug consumption of 1 kg / ha, pest death is 87%. The well-known drug Bitoxibacillin with the characteristics shown in example 1, provides the same efficiency at a rate of 3 kg / ha. When stored in the temperature range from -30 to +30 ^o C for 2.2 years, the drug lost about 20% of the activity of the spores, while maintaining activity of about 2100 EA / mg.

Claims (1)

 A method for producing an insecticidal preparation based on Bacillus thuringiensis, which comprises introducing substances such as photoprotector, antioxidant, adhesive, etc. into the sporocrystalline complex of bacteria, as well as sulphite-yeast bard, which are introduced in two stages, in the first of which it is introduced with stirring in an amount of 10-15 wt.% from the regulatory amount until the components of the spatial structure are formed from the mixture, and in the second stage, the remaining amount of stillage with stirring to form m coating on the structure.