Liquid culture medium for detecting beta-galactosidase and application of liquid culture medium in bacterium identification

Abstract

The invention discloses a liquid culture medium for detecting beta-galactosidase and application of the liquid culture medium in bacterium identification. Every 1,000 ml of the liquid culture medium for detecting beta-galactosidase is prepared from 5-50 g of nutrient substances, 2-10 g of sodium chloride, 50-250 ml of 0.2 mol/L PBS, 0.5-4 g of a specificity chromogenic substrate, 0.5-4 g of an enzyme induction agent, 0.1-10 ml of a cosolvent and 0.1-10 ml of a protection agent. According to the culture medium, 5-bromine-4-chlorine-3-indol-beta-D-galactoside is used as a substrate, the low-toxic cosolvent and the protection agent are adopted, and beta-galactosidase of living bacteria can be accurately and effectively detected through a liquid method; the culture medium can be applied to a commercial identification testing card, a drying substrate in a micro hole can be effectively redissolved, beta-galactosidase of the living bacteria is detected, the negative and positive results are clearer, and the identification accuracy for clinical common gram negative and positive bacteria is improved.

Description

technical field [0001] The invention relates to the field of microbial identification of in vitro diagnostic reagent technology, in particular to a liquid medium for detecting β-galactosidase and its application in bacterial identification. Background technique [0002] β-galactosidase, full name β-D-galactoside galactohydrolase (β-D-galactoside galacto-hydrolase), also known as lactase (Lactase), widely distributed in human body, animals, plants and microorganisms, it can catalyze the hydrolysis of the galactosidic bond in the β-galactoside compound, and also has the function of transgalactoside. Scholars at home and abroad have conducted extensive and in-depth research on β-galactosidase, among which the β-galactosidase in Escherichia coli is the most in-depth and thorough study, and thus put forward the lactose operon theory. Afterwards, β-galactosidase was widely used in molecular biology, microbiology and clinical testing. Because whether bacteria contain β-galactosid...

AI Technical Summary

Problems solved by technology

However, X-gal, as a water-insoluble substance, is difficult to dissolve in aqueous solution, so it is coated in the microwell of the test card, the detection effect is poor, the result interpretation is unclear and false negatives are prone to occur

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