Bacillus thuringiensis israelensis medium and application thereof

Abstract

The invention belongs to the technical field of a microbial medium, and specifically discloses a Bacillus thuringiensis israelensis medium. The weight percentage of each component is: 0.5-1% of sucrose, 0.6-1.2% of corn flour, 1-5% of bean cake powder, 0.1-0.5% of peptone, 0.4-1.2% of corn syrup, 0.1-0.5% of calcium carbonate, 0.05-0.1% of potassium dihydrogen phosphate, 0.05-0.1% of magnesium sulfate, 0.05-0.1% of zinc sulfate, 0.1-0.3% of sodium chloride, 0.01-0.05% of potassium nitrate, and 89.95 to 97.04% of deionized water. The invention also discloses an application of the above medium in the Bacillus thuringiensis israelensis. The medium can promote the rapid entry of Bacillus thuringiensis israelensis into a logarithmic growth phase, the proportion of viable spores of a fermentation broth is more than 90%, and the virulence to the Aedes aegypti and Culex pipiens pallens larvae is high, the medium greatly improves the product quality and reduces production costs, and is suitablefor large-scale cultivation and production.

Description

technical field [0001] The invention relates to a microorganism culture medium, in particular to a culture medium of Bacillus thuringiensis subspecies Israel. Background technique [0002] Bacillus thuringiensis subspecies Israel is a Gram-positive bacterium with blunt round ends, flagella, active movement, non-expanding sporangia, short oval or oval spores, and nearly round paraspore crystals. The main anti-mosquito active substance of Bacillus thuringiensis subsp. Israel is crystal protein, which is produced in the second stage of sporulation. It consists of three different types of crystals, located outside the outer membrane of the spore, and falls off with the release of the spore during growth. After the crystal protein is eaten by the larvae, the toxic peptide is dissociated under the action of the insect midgut alkaline protease, which destroys the normal function of the respiratory chain and causes the death of the mosquito larvae. Bacillus thuringiensis subsp. Isr...

AI Technical Summary

Problems solved by technology

In actual production, it is generally adopted to adjust the temperature, pressure, ventilation and agitation during the fermentation process to increase the number of effective viable bacteria, or to use high-temperature treatment on the spores of the strains, so that they can form spores synchronously during the industrial fermentation process, thereby Increase the number and ratio of spore formation to shorten the fermentation time, but these methods are cumbersome in actual operation steps and increase production costs

In addition, Bacillus thuringiensis subspecies Israel has the best poisonous effect on Aedes larvae, and its poisonous effect on Culex larvae is worse than that of Bacillus sphaericus. At present, the research on improving its virulence against Culex is mostly from strain screening and genetically modified engineering bacteria construction, etc. Implementation in one aspect increases research and development costs, and the operation is difficult and not suitable for success

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