Preparation process of live bacillus thuringiensis preparation

Abstract

The invention relates to a preparation process of a live bacillus thuringiensis preparation. The preparation process comprises the steps that bacillus thuringiensis is inoculated into a fermentation medium to be cultured after being subjected to primary and secondary seed enlarge culture; the quantity and conversion rate of bacillus are increased through fed-batch of a carbon source in the fermentation process, thus obviously increasing the unit yield and reducing the unit cost; after fermentation is completed, the fermentation liquor is concentrated by using a vacuum film concentrator and the soluble synergistic substances, growth-stimulated substances and bacteriostatic active substances in the fermentation liquor can be effectively recovered; the concentrated fermentation liquor is dried and granulated by multistage low temperature spray fluidized drying equipment, the granules are sorted and the fine powder is trapped by a cyclone separator and returns to be re-granulated, thus obtaining the bacillus thuringiensis product, wherein, through biological assay, the activity of each gram of the bacillus thuringiensis powder on cotton bollworms is not lower than 80000IU / mg and the content of insecticidal crystal proteins in the product is not lower than 13%; the tail gas is treated and is discharged up to the standard. The preparation process has the advantages that the active substances in the fermentation liquor can be furthest retained; the product quality and the equipment utilization rate are high; the biological activity is better maintained; the waste gas and the wastewater are discharged up to the standard; the preparation process can be used for large-scale industrial production.

Description

technical field [0001] The invention relates to a preparation process of a live bacillus thuringiensis preparation. Background technique [0002] Bacillus thuringiensis (Bt) is an important entomopathogenic bacterium and an important member of research and development of microbial insecticides in various countries in the world. The main advantages of Bt insecticides: 1. It is safe for humans and animals, and does not pollute the ecological environment; 2. It has specific poisonous effect on target pests, and is non-toxic to non-target pests and natural enemies such as silkworms; 3. Control effect Good, it has a wide range of control, and can be widely used in the control of pests such as agriculture, forestry, fruits, vegetables and urban garden plants, and pests are not easy to develop resistance; 4. It is easy to use and will not cause user poisoning when used; 5. Production process Simple, the main production raw materials are agricultural and sideline products, and the ...

AI Technical Summary

Problems solved by technology

[0005] 1. The filling coefficient of the fermentation tank is 60%-70%, and the utilization rate of the equipment is not high;

[0006] 2. Due to the batch fermentation used, the initial concentration of the fermentation medium is too high, the lag period after inoculation is longer, and more by-products are formed during the fermentation process, and the concentration of the fermentation product cannot increase, which eventually leads to higher fermentation costs;

[0007] 3. Flocculation / plate-and-frame filtration or centrifugation technology is generally used for the concentration of fermentation broth. These two technologies generally generate a large amount of wastewater, and the subsequent treatment costs are relatively high;

[0008] 4. The use of flocculation / plate-and-frame filtration or centrifugation technology will also cause the loss of active ingredients in the fermentation supernatant, resulting in a decline in the product effect;

[0009] 5. The inlet temperature of spray drying is generally set at 180°C to 200°C, and the outlet temperature is 80°C to 100°C. Under such a high working temperature, the number of bacteria in some varieties will decrease to a certain extent, which directly affects product quality

[0012] Fermentation and drying and granulation will produce a large amount of waste gas, which often contains volatile organic compounds (VOC), hydrogen sulfide, ammonia, mercaptans and other pollutants, accompanied by unpleasant stench. In the past, fermentation enterprises generally Discharge it directly or simply spray it with water, the two treatment methods will cause serious pollution to the environment