High Purity Nisin,Advanced Production Technology

The production process of nisin mainly includes fermentation, extraction, and purification steps. The following is a detailed explanation of this process:

Ⅰ. Fermentation Process

1. Strain Cultivation:

High-quality Lactococcus lactis is selected as the production strain.

The strain is initially cultivated using seed culture media to ensure its vitality and purity.

The strain is then inoculated into secondary culture media for larger-scale cultivation to increase the quantity and activity of the cells.

2. Fermentation Condition Control:

Strict control over temperature, pH, stirring speed, and other conditions during fermentation is required to ensure the normal growth of the bacteria and the production of nisin.

Generally, the fermentation temperature is controlled at around 30°C, while the pH is adjusted according to the strain characteristics and production process.

3. End of Fermentation:

The fermentation process is completed when nisin production reaches its peak. At this point, the fermentation broth contains a large amount of nisin along with other impurities.

Ⅱ. Extraction Process

1. Pretreatment of Fermentation Broth:

The fermentation broth must first undergo pretreatment to remove bacterial cells, proteins, and other large molecular impurities.

Pretreatment methods include centrifugation and filtration to ensure a smooth extraction process.

2. Extraction Methods:

Membrane Separation Technology: In recent years, membrane separation technology has been widely used in nisin extraction. This technology uses ultrafiltration and nanofiltration membranes to concentrate and purify the fermentation broth, offering high separation accuracy, low energy consumption, and ease of operation.

Traditional Methods: Traditional extraction methods include salting out and spray drying, which are simple but have high energy consumption and low efficiency.

3. Specific Steps:

Taking membrane separation technology as an example, the fermentation broth is first pretreated with plate-and-frame filtration to remove solid matter like bacterial cells.

The filtrate then enters an ultrafiltration membrane concentration system, where nisin is concentrated to a certain level through membrane retention.

The concentrated liquid is then subjected to salting out or spray drying, producing nisin powder.

Ⅲ. Purification and Drying

1. Purification:

The concentrated nisin extract may still contain small amounts of impurities, so a purification step is necessary to further improve its purity.

Purification methods include crystallization and recrystallization, which can be selected based on actual production needs.

2. Drying:

The purified nisin must be dried to remove moisture and form a stable powdered product.

Drying methods include vacuum drying and spray drying. Vacuum drying ensures rapid dehydration at low temperatures, maintaining the product's activity.

The production of nisin is a complex process involving multiple steps, including fermentation, extraction, purification, and drying. By optimizing the process conditions and technical parameters of these steps, nisin's yield and purity can be improved to meet the demands of the food industry and other sectors. In actual production, it is necessary to choose the appropriate process route and equipment configuration based on specific situations to ensure the stability and cost-effectiveness of the production process.