Method for synthesizing conjugated gamma-linolenic acid isomers catalyzed by surfactant-coated bacteria

Abstract

The invention discloses a method for catalytic synthesis of a conjugated gamma-linolenic acid isomer by virtue of a surfactant-coated bacterium, wherein the method comprises the following steps (1) re-suspending each gram of lactobacillus casei CGMCC 1.574 bacterium in 5ml of a permeabilization treatment solution, treating at 37 DEG C for 20min, centrifuging and collecting a permeabilized bacterium; (2) washing the permeabilized bacterium with 60mM of a phosphate buffer solution which is at 5.8 in pH value; centrifuging and collecting the bacterium; re-suspending each gram of the wet bacterium in 20mL of the 60mM of phosphate buffer solution which is at 5.8 in pH value, dropping an acetone solution which contains 1% of dioleyl glutamate ribitol and uniformly mixing at the same time; processing at 4-40 DEG C for 2-6h, centrifuging and collecting the bacterium, and freeze-drying so as to obtain a coated bacterium; (3) adding each gram of the freeze-dried coated bacterium to 500ml of normal hexane, uniformly stirring, adding 0.1-0.3% of gamma-linolenic acid in terms of the volume percentage of the normal hexane and reacting at 4-40 DEG C for 1-12h; and (4) centrifuging and isolating the coated bacterium and recovering the normal hexane, so as to obtain a finished product, namely c6,c9,t11-conjugated gamma-linolenic acid isomer. The method disclosed by the invention is short in reaction time; the coated bacterium can be recycled for several times, so that yield is significantly improved; and the method is free from environmental pollution and is capable of remarkably reducing production cost.

Description

technical field [0001] The invention belongs to the technical field of biomedicine. Background technique [0002] Conjugated γ-linolenic acid is a conjugated isomer of γ-linolenic acid, which is a general term for a group of octadecyl-conjugated trienoic acids. There are various positional isomers and geometric isomers, such as: c 6, c 9, t 11-conjugated γ-linolenic acid and c 6, t 10, c 12-conjugated γ-linolenic acid isomers, etc. Studies have shown that conjugated γ-linolenic acid has physiological functions such as anti-cancer, prevention of atherosclerosis, and weight loss, and its physiological activities are isomer-specific, such as: c 6, c 9, t 11-conjugated γ-linolenic acid isomers have anticancer effects. In nature, conjugated γ-linolenic acid mainly exists in the milk and meat fat of ruminants, mainly composed of c 6, c 9, t 11-conjugated γ-linolenic acid and other isomers, but its content is usually very low, which cannot meet the development and appli...

AI Technical Summary

Problems solved by technology

At present, microbial fermentation is carried out in aqueous solution. Since the fermentation substrate - γ-linolenic acid is a fat-soluble substance, γ-linolenic acid needs to be emulsified before being added to the fermentation broth, and the amount of addition is limited. The product of conjugated γ-linolenic acid needs to be extracted by organic solvent, and the whole production process has the disadvantages of long fermentation period, high production cost and low yield