Factory Supply 99% Nisin

Enhancing the purity of nisin is a complex process involving multiple steps and techniques. Below are the main steps and related information for improving the purity of nisin:

Control of Fermentation Conditions:

In large-scale fermentation tanks, the fermentation of Lactococcus lactis requires precise control of parameters such as fermentation temperature, pH value, oxygen concentration, stirring speed, and fermentation time. These conditions directly affect the yield and quality of nisin.

Extraction of Nisin:

Common extraction methods include acid extraction, organic solvent extraction, dialysis, and ultrafiltration. The acid extraction method is the most commonly used. Specific steps include adjusting the fermentation broth to an appropriate pH value, adding acid solution to precipitate the bacteria, centrifuging to remove the bacterial cells, and concentrating the supernatant to obtain a concentrated nisin solution.

Purification of Nisin:

The purification process removes impurities from nisin to improve its purity. Common purification methods include silica gel column chromatography, counter-current chromatography, ultrafiltration, and membrane separation. For example, purification using Sephadex G-50 dextran gel column chromatography involves collecting the elution peaks with antibacterial activity, concentrating them to the sample volume, and further purifying the nisin.

Additionally, a method for producing a high-purity nisin solution involves dissolving crude nisin powder in an organic acid solution, centrifuging to remove impurities and crude residues, and then using column chromatography for further purification to obtain a high-purity nisin solution.

Drying of Nisin:

The purified nisin solution needs to be dried to obtain powdered nisin products. Common drying methods include spray drying, lyophilization, and vacuum drying.

Key Points for Purity Enhancement:

During extraction and purification, finely controlling parameters such as pH value, temperature, and concentration, and selecting appropriate purification methods, can effectively enhance the purity of nisin. Using modern separation technologies like ultrafiltration, membrane separation, and chromatography can further improve the purity and recovery rate of nisin.

Purity Standards:

The potency of pure nisin is 40,000 IU/mg, while market products are usually a combination of nisin and sodium chloride with lower purity, having a potency greater than 900 IU/mg and a purity of about 2.5%. By optimizing extraction and purification processes, higher purity nisin products can be prepared.

Precautions:

During the purity enhancement process, it is essential to follow operational norms and safety protocols to avoid contamination and cross-contamination. Attention should also be paid to the quality and source of raw materials to ensure that the nisin source is reliable and meets food safety standards.

Enhancing the purity of nisin is a complex process requiring a comprehensive consideration of fermentation conditions, extraction methods, purification techniques, and drying methods. By optimizing process flow and parameter control, high-purity and high-quality nisin products can be obtained.