An extraction method for recovering nisin from nisin waste liquid

Abstract

The present invention provides a method for recovering nisin from nisin waste liquid, comprising the following steps: A. Adsorption: adding 0.1-1% w / v of an adsorption substance to the nisin waste liquid for adsorption; the adsorbent is one or more of activated carbon, gluten, gluten hydrolysis residue, diatomite or chitosan; B. Separation: separating the adsorption substance from the waste liquid by using a separation medium; C. Desorption: adding acid water to the adsorption substance for desorption to obtain a desorption solution; D. Impurity removal: removing impurities from the desorption solution by using a microfiltration water membrane to obtain a purified solution; E. Spray drying: spray drying the purified solution to obtain a dry product of nisin. The present invention recovers the nisin product from the waste liquid by means of physical adsorption. The present invention has the advantages of not using organic solvents such as solvents, having little environmental pollution, simple process, strong operability and improving the production yield.

Description

Technical Field

[0001] The present invention belongs to the field of food preservatives, and particularly relates to an extraction method for recovering nisin from nisin waste liquid. Background Art

[0002] Nisin is a safe, non-toxic and highly efficient natural food preservative, which can be used for the anti-corrosion and preservation of meat products, dairy products, plant protein foods, canned foods, etc. Nisin solves the problem of short-time low-temperature sterilization and fundamentally improves the taste of food. In 1969, the Joint Expert Committee on Food Additives of the Food and Agriculture Organization of the United Nations and the World Health Organization (FAO / WHO) confirmed that nisin can be used as a food preservative. In 1988, the US FDA (US Food and Drug Administration) confirmed that nisin is a GRAS (Generally Recognized as Safe) food additive.

[0003] At present, the industrial production of nisin mainly adopts the fermentation method of Streptococcus lactis. For example, the publicly disclosed fermentation process patents CN111621536A and CN101948893B extract nisin from the fermentation broth. The fermentation method and extraction process of Streptococcus lactis in this application adopt the patent CN111662365A.

[0004] The average yield of the nisin industry is 80-85%, and about 10-15% of nisin remains in the waste liquid. The waste liquid mainly comes from the wastewater in the solid-liquid separation and membrane concentration processes of nisin. The residual nisin in the waste liquid will cause the sewage COD index to be too high, making sewage treatment difficult and having a certain impact on sewage treatment and environmental pollution. Therefore, it is necessary to recover the residual nisin in the wastewater.

[0005] Some manufacturers adopt the resin adsorption process or the organic solvent extraction process to recover nisin from the waste liquid. This process involves the use of solvents, which causes great environmental pollution, great harm to the physical health of operators, requires high equipment requirements, and requires a large amount of equipment investment. Therefore, many manufacturers have given up recovering nisin from the waste liquid. Summary of the Invention

[0006] The purpose of the present invention is to solve the disadvantages existing in the prior art and provide a simple and practical extraction method for recovering nisin.

[0007] The technical solution adopted by the present invention is: an extraction method for recovering nisin from nisin waste liquid, comprising the following steps:

[0008] A. Adsorption: Add 0.1 - 1% w / v of an adsorbent to the nisin waste liquid for adsorption; the adsorbent is one or more of activated carbon, gluten, hydrolyzed gluten residue, diatomaceous earth, or chitosan;

[0009] B. Separation: Use a separation medium to separate the adsorbent from the waste liquid;

[0010] C. Desorption: Add acid water to the adsorbent for desorption to obtain a desorbed solution;

[0011] D. Impurity removal: Use a microfiltration water membrane to remove impurities from the desorbed solution to obtain a purified solution;

[0012] E. Spray drying: Spray dry the purified solution to obtain dry nisin.

[0013] Further, the acid water is one of hydrochloric acid or sulfuric acid.

[0014] Further, the pore size of the microfiltration water membrane is 0.45 μm.

[0015] Further, the separation medium is a centrifuge, plate and frame, or Buchner funnel.

[0016] The beneficial effects obtained by the present invention are as follows: The present invention uses physical adsorption to recover nisin products from waste liquid. The present invention has the advantages of not using organic solvents such as solvents, having little environmental pollution, simple process, strong operability, improving production yield, less equipment investment, and no harm to human health, and can increase the production yield by 10 - 15%. Description of the Drawings

[0017] Figure 1 It is the HPLC - UV detection chromatogram of the nisin finished product powder prepared in Example 1 of the present invention;

[0018] Figure 2 It is the HPLC - UV detection chromatogram of the nisin finished product powder prepared in Example 2 of the present invention;

[0019] Figure 3 It is the HPLC - UV detection chromatogram of the nisin finished product powder prepared in Example 3 of the present invention;

[0020] Figure 4 It is the HPLC - UV detection chromatogram of the nisin finished product powder prepared in Example 4 of the present invention;

[0021] Figure 5 It is the HPLC - UV detection chromatogram of the nisin finished product powder prepared in Example 5 of the present invention. Detailed Embodiments

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0023] Example 1

[0024] Take 10 L of nisin waste liquid (titer 2 g / L), add 0.2% (w / v) activated carbon and 0.2% (w / v) gluten to the waste liquid, stir and adsorb at 25 °C for 30 minutes, with a rotation speed of 150 revolutions per minute, filter using a Buchner funnel, and detect that the titer of the adsorbed wastewater is 0.18 g / L. Add 2 L of hydrochloric acid aqueous solution with a pH of 2.53 to the adsorption medium, stir for 30 minutes, and filter by suction to obtain 2.03 L of nisin desorption solution with a titer of 8.96 g / L. The desorption solution passes through a 0.45-μm water membrane to obtain 2.03 L of purified solution. The purified solution is spray-dried to obtain 20.01 g of finished product powder, the purity of the finished product powder is 90.09%, and the recovery rate is 90.13%.

[0025] Example 2

[0026] Take 10 L of nisin waste liquid (titer 2 g / L), add 0.2% (w / v) gluten and 0.3% (w / v) gluten hydrolysis residue to the waste liquid, stir and adsorb at 27 °C for 30 minutes, with a rotation speed of 180 revolutions per minute, filter using a plate and frame filter, and detect that the titer of the adsorbed wastewater is 0.26 g / L. Add 2 L of hydrochloric acid aqueous solution with a pH of 2.58 to the adsorption medium, stir for 30 minutes, and filter by suction to obtain 2.02 L of nisin desorption solution with a content of 8.7 g / L. The desorption solution passes through a 0.45-μm water membrane to obtain 2.02 L of purified solution. The purified solution is spray-dried to obtain 19.39 g of finished product powder, the purity of the finished product powder is 90.63%, and the recovery rate is 87.87%.

[0027] Example 3

[0028] Take 10 L of nisin waste liquid (titer 2 g / L), add 0.2% (w / v) gluten and 0.25% (w / v) chitosan to the waste liquid, stir and adsorb at 26 °C for 30 minutes, with a rotation speed of 200 revolutions per minute, separate using a centrifuge, and detect that the titer of the adsorbed wastewater is 0.15 g / L. Add 2 L of hydrochloric acid aqueous solution with a pH of 2.56 to the adsorption medium, stir for 30 minutes, and filter by suction to obtain 2.025 L of nisin desorption solution with a content of 9.25 g / L. The desorption solution passes through a 0.45-μm water membrane to obtain 2.02 L of purified solution. The purified solution is spray-dried to obtain 20.55 g of finished product powder, the purity of the finished product powder is 90.03%, and the recovery rate is 92.5%.

[0029] Example 4

[0030] Take 10 L of nisin waste liquid (potency 2 g / L), add 0.2% (w / v) of gluten powder and 0.28% (w / v) of diatomaceous earth to the waste liquid, stir and adsorb at 23°C for 30 minutes at a rotation speed of 160 revolutions per minute, filter using a Buchner funnel, and detect that the potency of the adsorbed wastewater is 0.32 g / L. Add 2 L of hydrochloric acid aqueous solution with a pH of 2.52 to the adsorption medium, stir for 30 minutes, and filter with suction to obtain 2.028 L of nisin desorption solution with a content of 9.062 g / L. Pass the desorption solution through a 0.45-μm water membrane to obtain 2.022 L of purified solution. Spray-dry the purified solution to obtain 20.12 g of finished product powder with a purity of 90.07% and a recovery rate of 90.62%.

[0031] Example 5

[0032] Take 10 L of nisin waste liquid (potency 2 g / L), add 0.3% (w / v) of hydrolyzed gluten residue and 0.25% (w / v) of diatomaceous earth to the waste liquid, stir and adsorb at 23°C for 30 minutes at a rotation speed of 150 revolutions per minute, filter using a Buchner funnel, and detect that the potency of the adsorbed wastewater is 0.28 g / L. Add 2 L of hydrochloric acid aqueous solution with a pH of 2.53 to the adsorption medium, stir for 30 minutes, and filter with suction to obtain 2.02 L of nisin desorption solution with a content of 9.013 g / L. Pass the desorption solution through a 0.45-μm water membrane to obtain 2.02 L of purified solution. Spray-dry the purified solution to obtain 20.15 g of finished product powder with a purity of 89.43% and a recovery rate of 90.10%.

[0033] The detection principle of the products in the above examples: Nisin is a polypeptide substance containing 34 amino acid residues. Its specific structure and composition endow it with ultraviolet absorption characteristics, so it can be detected by HPLC-UV method.

[0034] Liquid phase detection equipment model: Waterse2695-2489.

[0035] Standard product: Sigma standard product.

[0036] The present invention mainly optimizes the nisin recovery process. The present invention can effectively recover nisin products from production waste liquid, effectively improve production efficiency, reduce production costs, improve the enterprise's sewage treatment capacity, reduce environmental pollution, and is easy to operate and suitable for industrial production of products.

[0037] As described above, the above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. An extraction method for recovering nisin from nisin waste liquid, characterized in that: It includes the following steps: A. Adsorption: Add 0.1% w / v - 1% w / v of an adsorbent to the nisin waste liquid for adsorption; The adsorbent is one of 0.2% w / v of activated carbon and 0.2% w / v of gluten, or 0.2% w / v of gluten and 0.3% w / v of gluten hydrolysis residue, or 0.2% w / v of gluten and 0.25% w / v of chitosan, or 0.2% w / v of gluten and 0.28% w / v of diatomaceous earth, or 0.3% w / v of gluten hydrolysis residue and 0.25% w / v of diatomaceous earth; B. Separation: Use a separation medium to separate the adsorbent from the waste liquid; C. Desorption: Add acid water to the adsorbent for desorption to obtain a desorbed solution; D. Impurity removal: Use a microfiltration water membrane to remove impurities from the desorbed solution to obtain a purified solution; E. Spray drying: Spray dry the purified solution to obtain dry nisin; The acid water is hydrochloric acid with a content of 5% - 10%, and the dosage of the acid water is calculated based on 10 g / L of nisin.

2. The extraction method for recovering nisin from the waste liquid of nisin-producing Streptococcus lactis according to claim 1, characterized in that: The pore size of the microfiltration water membrane is 0.45 μm.

3. The extraction method for recovering nisin from the waste liquid of nisin-producing Streptococcus lactis according to claim 1, characterized in that: The separation medium is a centrifuge, a plate and frame, or a Buchner funnel.

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