阅读说明：本技术 一种蛋氨酸锌含量高的富锌酵母的生产方法 (Production method of zinc-rich yeast with high zinc methionine content ) 是由 朱振华 于 2019-10-10 设计创作，主要内容包括：本发明公开了一种蛋氨酸锌含量高的富锌酵母的生产方法,通过将酿酒酵母菌种接种到含锌的葡萄糖培养基中培养筛选出锌的酵母菌种,然后采用含有小球藻抑菌肽粉和多种微量元素的培养基进行菌种培养,流加硫酸锌溶液,直至发酵结束,最终得到的富锌酵母,蛋氨酸锌的含量可以提升至75%以上,该方法生产的富锌酵母稳定性好、生物学效价较高。(The invention discloses a method for producing zinc-rich yeast with high zinc methionine content, which comprises the steps of inoculating a saccharomyces cerevisiae strain into a zinc-containing glucose culture medium to culture and screen out zinc yeast strains, then adopting a culture medium containing chlorella antibacterial peptide powder and a plurality of trace elements to culture the strains, and adding zinc sulfate solution in a flowing manner until fermentation is finished, wherein the zinc-rich yeast finally obtained has the zinc methionine content which can be increased to more than 75 percent.)

1. A production method of zinc-rich yeast with high methionine zinc content is characterized by comprising the following steps:

A. preparing yeast strains with strong organic zinc conversion capacity: inoculating Saccharomyces cerevisiae strain to zinc-containing glucose culture medium A, culturing, and screening out strain with strong zinc resistance as mutagenesis strain; inoculating yeast strains with strong zinc resistance into a mutagenesis culture medium for mutagenesis culture for 20-45 h; separating and screening the mutagenized strains, inoculating the strains to a zinc-containing glucose culture medium B for culture, and screening out strains with strong organic zinc transformation capacity, namely the high-transformation zinc-rich yeast strains;

B. and (3) strain culture: putting the culture medium into a seeding tank, sterilizing, and inoculating a high-transformation zinc-rich yeast strain into the culture medium in the seeding tank for culture; the temperature of the seeding tank is 33 +/-3 ℃, the initial pH4.0-4.8, and the culture time is 16 +/-2 hours;

C. and (3) amplification culture: transferring the strain to a fermentation tank for enlarged culture; the temperature of the fermentation tank is 30 plus or minus 2 ℃, the pH value is 5.2 to 5.8, when the wet weight of the thalli reaches 2.1 to 2.3g/10ml, zinc sulfate solution starts to be fed-batch until the fermentation is finished, and the culture time is 36 plus or minus 2 hours;

D. inactivation: inactivating at 75-77 deg.C for 25-35 min;

E. spray drying: the inlet temperature is 205 ℃ and 230 ℃, the outlet temperature is 85-95 ℃, and the mixture is sieved, mixed and packaged.

2. The method for producing a zinc-rich yeast with high content of zinc methionine as claimed in claim 1, wherein in the step A, the mutagenizing medium contains a mutagenizing agent, and the mutagenizing agent in the mutagenizing medium is N-methyl-N-nitro-N-nitrosoguanidine.

3. The method for producing a zinc-rich yeast with high content of zinc methionine according to claim 1, wherein in the step B, the culture medium comprises carbon source, nitrogen source, inorganic salt, chlorella antibacterial peptide powder and a small amount of trace elements.

4. The method for producing a zinc-rich yeast having a high content of zinc methionine according to claim 3, wherein the nitrogen source is an organic nitrogen source containing amino nitrogen.

5. The method for producing a zinc-rich yeast with high zinc methionine content according to claim 4, wherein the organic nitrogen source containing amino nitrogen is a plant protein or an amino acid.

6. The method for producing zinc-rich yeast with high content of zinc methionine as claimed in claim 4, wherein the culture medium comprises the following components in parts by weight: 500 parts of fermentable reducing sugar, 50-70 parts of organic nitrogen source containing amino nitrogen, 6-10 parts of ammonium dihydrogen phosphate, 5-8 parts of magnesium sulfate, 1-3 parts of chlorella antibacterial peptide powder and 0.1-0.3 part of trace elements.

7. The method for producing a zinc-rich yeast with high content of zinc methionine as claimed in claim 3 or 4, wherein the trace elements comprise: ca²⁺、Fe²⁺、Mo²⁺And Mn²⁺。

8. The method for producing a zinc-rich yeast with high zinc methionine content as claimed in claim 1, wherein the organic nitrogen source is supplemented every 4-8 hours after the start of the zinc sulfate solution feeding, and ammonia water is used to control the pH value during the process.

Technical Field

The invention relates to the technical field of yeast, in particular to a production method of zinc-rich yeast with high zinc methionine content.

Background

Zinc is a necessary trace element for animal body and is called "vital element". When the human body lacks zinc, growth retardation can occur; dysplasia in the juvenile period, dysgeusia, slow wound healing, and the like; pregnant women lack zinc and even have fetal deformity. The Chinese is wide in source, the composition of diet is mainly cereal, zinc deficiency is caused by insufficient intake of zinc in food or too much intake of fiber in diet to influence the absorption of zinc, and the zinc deficiency condition of children is common. The daily zinc intake of adults recommended in China is 10-15mg, and according to the analysis of the Chinese preventive medicine academy of sciences on the zinc content in hair of 19 provincial and urban children such as Beijing, about 60 percent of the children are lower than the normal value. The zinc deficiency is serious in the pathological conditions of zinc deficiency, such as poor growth and development of children, dwarfism, dementia and the like. The zinc content in natural food is generally low, and the zinc content in the natural food is not enough to meet the normal requirement of human body.

At present, inorganic zinc such as high-dosage zinc oxide, zinc sulfate and the like is mostly adopted as a zinc nutrition additive in China, but the inorganic zinc has low biological value and large addition amount and is easy to cause serious environmental pollution; the application of the amino acid complex zinc salt (such as zinc methionine, zinc gluconate and the like) with good stability and higher biological value is limited due to the complex production process and higher price. The zinc-rich yeast can not only meet the requirement of animal organisms on zinc, but also has rich nutrient components in the yeast and can play a synergistic role.

The Chinese invention patent CN107119038A discloses a method for producing zinc-rich yeast products, which can produce zinc-rich yeast with zinc content of 1000-5000mg per kilogram of yeast, but the zinc content of methionine in the zinc-rich yeast is less than 30%, which is not beneficial to animal absorption, so that the method for producing zinc-rich yeast with high zinc content of methionine needs to be researched.

Disclosure of Invention

Based on the technical problems in the background art, the invention provides a production method of zinc-rich yeast with high zinc methionine content.

The technical scheme of the invention is as follows:

a production method of zinc-rich yeast with high methionine zinc content comprises the following steps:

A. preparing yeast strains with strong organic zinc conversion capacity: inoculating Saccharomyces cerevisiae strain to zinc-containing glucose culture medium A, culturing, and screening out strain with strong zinc resistance as mutagenesis strain; inoculating yeast strains with strong organic zinc conversion capability into a mutagenesis culture medium for mutagenesis culture for 20-45 h; separating and screening the mutagenized strains, inoculating the strains to a zinc-containing glucose culture medium B for culture, and screening out strains with strong organic zinc transformation capacity, namely the high-transformation zinc-rich yeast strains;

B. and (3) strain culture: putting the culture medium into a seeding tank, sterilizing, and inoculating a high-transformation zinc-rich yeast strain into the culture medium in the seeding tank for culture; the temperature of the seeding tank is 33 +/-3 ℃, the initial pH4.0-4.8, and the culture time is 16 +/-2 hours;

C. and (3) amplification culture: transferring the strain to a fermentation tank for enlarged culture; the temperature of the fermentation tank is 30 +/-2 ℃, the pH value is 5.2-5.8 (the pH value is adjusted by sodium hydroxide), when the wet weight of the thalli reaches 2.1-2.3g/10ml, zinc sulfate solution is fed-batch until the fermentation is finished, and the culture time is 36 +/-2 hours;

D. inactivation: inactivating at 75-77 deg.C for 25-35 min;

E. spray drying: the inlet temperature is 205 ℃ and 230 ℃, the outlet temperature is 85-95 ℃, and the mixture is sieved, mixed and packaged.

Preferably, in the step a, the mutagenesis medium contains a mutagen, and the mutagen in the mutagenesis medium is N-methyl-N-nitro-N-nitrosoguanidine.

Preferably, in the step B, the components of the culture medium are a carbon source, a nitrogen source, inorganic salts, chlorella antibacterial peptide powder and a small amount of trace elements.

Preferably, the nitrogen source is an organic nitrogen source containing amino nitrogen, and more preferably, the organic nitrogen source containing amino nitrogen is a plant protein or an amino acid.

Further preferably, the components of the culture medium consist of the following components in parts by weight: 500 parts of fermentable reducing sugar, 50-70 parts of organic nitrogen source containing amino nitrogen, 6-10 parts of ammonium dihydrogen phosphate, 5-8 parts of magnesium sulfate, 1-3 parts of chlorella antibacterial peptide powder and 0.1-0.3 part of trace elements.

Preferably, the trace elements include: ca²⁺、Fe²⁺、Mo²⁺And Mn²⁺。

Further preferably, the organic nitrogen source is supplemented every 4 to 8 hours after the zinc sulfate solution is initially fed, and ammonia water is used for controlling the pH value in the process.

The invention has the advantages that: the zinc-rich yeast produced by the method has good stability and high biological value, and the zinc-rich yeast is obtained by inoculating a saccharomyces cerevisiae strain into a zinc-containing glucose culture medium to culture and screen out the zinc-containing yeast strain, then performing strain culture by adopting a culture medium containing chlorella antibacterial peptide powder and various trace elements, and adding zinc sulfate solution in a flowing manner until fermentation is finished.

Detailed Description