Preparation method of nitrite reductase and enzyme product thereof

A technology of nitrite and reductase, which is applied in the field of separation and purification of lactic acid bacteria nitrite reductase, can solve problems such as nitrite pollution and nitrite exceeding the standard, achieve good stability, improve food safety and quality, and prevent food Effects of poisoning and cancer

Inactive Publication Date: 2009-12-09
SHANGHAI INST OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, due to the extensive use of nitrogen fertilizers, as well as the use of industrial wastewater and domestic sewage for irrigation in some areas, nitrite pollution in water is serious; excessive nitrite in vegetables, grains, and feedstuffs is also common
In addition, there has always been a problem of excessive nitrite in traditional pickles and various meat sausages

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0052] (1) Inoculate the lactic acid bacteria in the MRS medium with 3% inoculum amount, cultivate the first-generation strains at 30°C for 20 hours, then connect the first-generation strains with 5% inoculum amount to the MRS medium, and incubate at 30°C Cultivate for 20 hours to obtain the second generation strain.

[0053] (2) The second-generation bacterial strain was connected to the MRS fermentation medium according to the inoculation amount of 5% of the volume of the fermentation medium, and the pH value of the medium was adjusted to 6.2, and cultured at 30° C. for 30 h.

[0054] (3) Adjust the pH value of the above fermentation broth to 6.2. Add sodium nitrite solution 0.2mg / ml, and incubate at 30°C for 16h.

[0055] (4) Collect the precipitate by centrifuging the above fermentation broth at 8000r / min, 4°C for 5min;

[0056] (5) Add 4 times the volume of phosphate buffer solution of pH 6.5 to the precipitate, after the precipitate is completely suspended, centrifuge ...

Embodiment 2

[0063] (1) Strain activation: inoculate lactic acid bacteria into MRS medium with 5% inoculum amount, cultivate at 27°C for 22 hours to obtain the first-generation strain, and then inoculate the first-generation strain with 5% inoculum amount into MRS medium , Cultivated at 27°C for 20h to obtain the second-generation strain.

[0064] (2) The second-generation bacterial strain was connected to the MRS fermentation medium according to the inoculation amount of 3% of the volume of the fermentation medium, and the pH value of the medium was adjusted to 6.8, and cultured at 25° C. for 36 hours.

[0065] (3) Adjust the pH value of the above fermentation broth to 6.2. Add sodium nitrite solution 0.40mg / ml, and incubate at 30°C for 16h.

[0066] (4) Collect the precipitate by centrifuging the above fermentation broth at 4000r / min, 4°C for 20min;

[0067] (5) Add 5 times the volume of pH 7.5 phosphate buffer to the precipitate to suspend the precipitate completely, centrifuge at 400...

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PUM

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Abstract

The invention discloses a preparation method of nitrite reductase, comprising the following steps: inoculating lactobacillus in a MRS culture medium to culture a first generation strain and then to culture a second generation strain; inoculating the second generation strain in a MRS fermentation culture medium to culture for 30-48h; adding sodium nitrite solution in the fermentation solution to culture for 16-32h; collecting precipitate; adding buffer solution in precipitate to fully suspend the fermentation liquor precipitate, adding lysozyme solution and treating the mixture by ultrasonication to obtain broken cell solution, collecting supernatant; filtrating the supernatant and collecting the filtrate; separating the filtrate with a sephadex chromatographic column to obtain precipitate, namely, nitrite reductase and adding 10-50% of starch in the precipitate to obtain the enzyme product. The enzyme preparation prepared by the method can be used to remove the residue of nitrite in food, feed and environment, improves the food safety and quality and prevents the poisoning, cancer and the like caused by nitrite.

Description

technical field [0001] The invention relates to a method for separating and purifying nitrite reductase of lactic acid bacteria and an enzyme preparation obtained by the method. Background technique [0002] Nitrite is one of the main chemical pathogenic factors of food poisoning in my country in recent years. After nitrite is absorbed into the blood, it can make Fe in normal hemoglobin 2+ Oxidized to Fe 3+ , causing hemoglobin to lose its oxygen-carrying function, resulting in tissue hypoxia, and even hypoxia asphyxia. Nitrite is also a precursor of strong carcinogen nitrosamines, which is a potential carcinogenic hazard. It reacts with secondary amines in proteolytic intermediates to form nitrosamines, which can induce various cancers such as liver cancer, gastric cancer, esophageal cancer and pharyngeal cancer [0003] At present, due to the extensive use of nitrogen fertilizers and the use of industrial wastewater and domestic sewage for irrigation in some areas, the...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C12N9/06C12N9/96A23K1/165A23L1/015A62D3/02C12R1/25C12R1/245C12R1/225C12R1/46C12R1/01A62D101/47A23K20/189A23L5/20
Inventor 龚钢明吕玉涛管世敏
Owner SHANGHAI INST OF TECH
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