Method for high-density fermentation of selenium-enriched lactobacillus reuteri

Abstract

The invention discloses a method for high-density fermentation of selenium-enriched lactobacillus reuteri. A high-density fermentation selenium-enriched lactobacillus reuteri bacterium is obtained byusing an improved culture medium with cane sugar, the capability of a fermentation liquid of a unit volume in digesting and absorbing inorganic selenium is improved, the concentration of selenium in the fermentation liquid is controlled to be at a relatively low level through second-stage selenium replenishment, the inorganic selenium in the fermentation liquid is completely converted into organicselenium in the lactic acid bacteria in the fermentation process of the lactic acid bacteria, in addition, as the concentration of the selenium in the fermentation process is controlled, bacterial can grow without limit, a relatively high viable bacterial concentration can be achieved within 24 hours, the problem that lactic acid bacteria grow slowly as the content of the inorganic selenium in the culture medium of a conventional process is far higher that the resistance of the lactic acid bacteria is solved, and meanwhile the problem that the bacterium comprises elemental selenium is avoided. Therefore, the selenium-enriched lactobacillus reuteri fermentation liquid disclosed by the invention has the advantages of both complete organic selenium and high viable counts. In addition, a finally obtained microecological preparation has only organic selenium.

Description

technical field [0001] The invention belongs to the field of biological products, in particular to a method for high-density fermentation of selenium-enriched Lactobacillus reuteri. Background technique [0002] Selenium is an essential element for the human body. It is certain that low selenium can lead to Kaschin-Beck disease and Keshan disease. In addition, selenium deficiency can potentially affect human health in many ways. For a long time, the lack of regional selenium sources has seriously affected people's health and living standards, and the development of selenium-enriched functional foods can effectively alleviate this problem. Selenium mainly exists in the form of inorganic selenium salts, simple organic selenium compounds and selenium-containing amino acids. Organic selenium has low toxicity, and there are two known selenium-containing amino acids: selenide methionine and selenide cysteine. Selenized amino acids can be synthesized into specific proteins throug...

AI Technical Summary

Problems solved by technology

In traditional methods, the concentration of lactic acid bacteria after fermentation is generally lower than (0.8-5)×10 9 CFU / ml, and the concentration of sodium selenite added in the cultivation process is 5-120mg / L, which is much higher than the tolerance concentration of lactic acid bacteria, resulting in slow growth of lactic acid bacteria, and the fermentation time usually takes more than 36h, which takes a long time and The number of living bacteria at the end point is low, so the cost of selenium enrichment is high

In addition, the residual sodium selenite in the fermentation broth obtained by the traditional method is extremely high, and it usually needs to be washed to remove most of the sodium selenite. After washing, there is still a high amount of selenium that has not been absorbed and transformed during the fermentation process. monomer and sodium selenite, so the resulting cells are mostly a mixture of inorganic selenium and organic selenium, which affects the use of cell products

[0006] In view of the low fermentation density of patented lactic acid bacteria and the problem that the selenium product of the obtained bacterial preparation is a mixture of inorganic selenium and organic selenium, the inventors of this case sought to develop a method to increase the fermentation density and reduce production costs, and the microbial preparation finally obtained contained The selenium product is the selenium enrichment method of organic selenium