Method for high throughput screening and separation of bacillus thuringiensis and application

Abstract

The invention belongs to the field of microbiology and discloses a method for high throughput screening and separation of bacillus thuringiensis (Bt for short) and application. The method is characterized in that absolute biomass and relative proportion of Bt cells in a sample are greatly improved by selective culture of continuous three-step different strategies; colony counts needing to be picked for transfer culture and microscopic examination are reduced, separating efficiency is greatly improved and greater convenience in operation is realized; meanwhile, the needed sample quantity is reduced and high-throughput operation can be realized; the method is particularly suitable for separating Bt strains from samples with small sample amount or samples with small Bt biomass.

Description

technical field [0001] The invention relates to the field of microbiology, in particular to a method and application for high-throughput screening and isolation of Bacillus thuringiensis (abbreviated as Bt). Background technique [0002] Bacillus thuringiensis (Bt) is one of the most successful and widely used biocontrol microorganisms, and has important research and application value in biopesticides and transgenic insect-resistant breeding. The isolation of Bt strains from nature is a long-term basic work and the most important content of bio-control resource mining. There are four existing methods for separating and screening Bt: [0003] 1. Direct separation method [0004] The direct separation method is a common separation method for bacteria. The method is to prepare the sample into a suspension, serially dilute it and spread it on an LB plate to cultivate a single colony visible to the naked eye. Cultivate on the culture medium until the spore stage, and screen th...

AI Technical Summary

Problems solved by technology

The advantage of this method is that it increases the chance of isolating non-spore-forming Bt bacterial strains, but its disadvantage is that the step of spore-forming culture is not selective to Bt bacterial strains, and other spore-like bacteria are also spore-forming at the same time, which cannot be filtered out by high-temperature treatment. It is necessary to pick a large number of colonies for transfer culture and microscopic screening, which is time-consuming and laborious, and the efficiency of isolation is relatively low

[0011] In summary, there are various defects in the four existing isolation methods. The main reason is that although Bt strains are widely distributed in nature, most of them are not dominant populations and are at a competitive disadvantage in the co-cultivation of the isolation process. The efficiency is relatively low, the workload is relatively large, and it is difficult to achieve high-throughput operations

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