L-isoleucine, as one of the eight essential amino acids and one of the three branched chain amino acids in the human body, plays an important role in human life metabolism due to its unique structure and function. It is a raw material for synthesizing hormones, enzymes, etc., which has the effect of promoting protein synthesis and inhibiting its decomposition. L-isoleucine has been widely used in the food industry, biomedicine, cosmetics, tissue engineering, photochemistry, electrochemistry, and other fields.
Physiological functions and effects
L-isoleucine is one of the eight essential amino acids in the human body, as well as one of the three branched chain amino acids. It plays a very important role in the growth and metabolism of the human body. If the human body lacks isoleucine for a long time, it can affect the physiological functions of the body, leading to metabolic turbulence and decreased resistance. L-isoleucine, as an essential amino acid for livestock and poultry, has a special nutritional effect on animals, mainly due to its special physiological functions such as regulating protein metabolism, enhancing immune function, improving lactation performance, oxidative energy supply, and neuromodulatory function. Therefore, research on L-isoleucine as a branched chain amino acid has attracted great attention.
Surfactants and antibacterial agents made from amino acids such as L-isoleucine and advanced fatty acids have low toxicity, low irritation, softness, anti-static, bactericidal properties, and can be used to make cosmetics such as skincare and hair care products.
Fermentation and Separation Purification
A fermentation and separation purification method for L-isoleucine, mainly achieved through the following steps:
1) High yield strain screening: Fresh lactose fermented Bacillus subtilis JHI3-156 was injected with a certain amount of nitrogen ions (N+) with a certain injection energy and injection dose, and cultured on a 0.8% Eth (ethionine) basic medium plate. The strain JHN224 was obtained through growth circle method and shake flask fermentation re screening. Fresh JHN224 was mutated by ultraviolet light irradiation, and then cultured in darkness in a test tube containing 5mL of 0.6% Ethh basic medium. The L-isoleucine producing strain JHI4-102 (CGMCC N0.8091) was obtained through growth circle method and shake flask fermentation re screening, which exhibited good genetic stability.
2) Fermentation in a fermentation tank: The strain is gradually expanded and cultivated through seeds, and under certain conditions, it is fermented in a 50L to 100L fermentation tank.
3) Extraction and purification: The fermentation broth is pretreated with chitosan and then ultrafiltration, by vacuum concentration of the ultrafiltration solution, crystallization and recrystallization of ethanol, and vacuum drying to obtain a white flake like L-isoleucine product.