Method for purifying and separating gamma-polyglutamic acid from fermentation liquor

Abstract

The invention discloses a method for purifying and separating gamma-polyglutamic acid from fermentation liquor. Through the utilization of the characteristic that only the gamma-polyglutamic acid can be separated out in a fermentation liquor filtrate with low pH value, the purpose of separating and purifying high-purity gamma-polyglutamic acid is achieved. The method comprises the following steps: adjusting the pH value to be 3.0-6.0 with acid, performing filtration sterilization, then, decolorizing with activated carbon, adjusting the pH value to be 2.0-5.0 with acid, leaving to stand, separating out sediments, performing solid-liquid separation, dissolving the sediments in purified water to obtain a high-concentration water solution, finally, performing band drying, and smashing, so as to obtain the gamma-polyglutamic acid finished product. According to the invention, the process route is novel and simple, an organic solve is completely avoided, the product has no organic solvent residue, the production cost is low, the cost is reduced by 30% or above, the yield is as high as 85% or above, the product quality is excellent, the purity reaches 95% or above, and the method is more suitable for industrial production.

Description

technical field

[0001] The invention relates to a method for separating and purifying gamma-polyglutamic acid from fermentation liquid, belonging to the technical field of industrial microorganisms. Background technique

[0002] γ-polyglutamic acid (γ-PGA) is a high-molecular amino acid polymer synthesized by microorganisms. It has a large number of highly active free side chain carboxyl groups (-COOH) on its molecular chain, and has extremely high water absorption and moisturizing properties. It is easy to combine with some drugs to form a stable complex, which is an ideal class of biodegradable medical polymer materials. It has no pollution to the environment, is a green biological product, and has many unique physical, chemical and biological properties such as excellent biodegradability, film-forming property, fibrillation property, plasticity, cohesiveness, moisture retention and many others. Today, with emphasis on environmental protection and sustainable development,...