Preparation method and application of poly (R)-3-hydroxybutyrate

Abstract

The invention belongs to the technical field of biochemical engineering, and discloses a preparation method and application of poly (R)-3-hydroxybutyrate. The method comprises the following steps: firstly, carrying out reflux treatment on a high-molecular-weight PHB crude product by adopting an ethanol solution, so that ethanol permeates into the internal structure of the PHB crude product; then degrading and purifying the PHB crude product under the combined action of protease and lipase; and after the solid-liquid separation, purifying the supernatant to realize the recovery of (R)-hydroxybutyric acid. And soaking the solid precipitate with ethanol to prepare the poly (R)-3-hydroxybutyrate with high purity, low molecular weight, low dispersity and low endotoxin content. According to the method, the poly (R)-3-hydroxybutyrate can be purified, molecular weight grading is achieved, and the byproduct (R)-hydroxybutyric acid can be reasonably recycled. The method is simple to operate, has low requirements on production equipment, does not use toxic solvents, and is environment-friendly.

Description

technical field [0001] The invention belongs to the technical field of biochemical industry, and in particular relates to a preparation method and application of poly(R)-3-hydroxybutyrate. Background technique [0002] Biopolymer materials obtained by biological fermentation are one of the most rapidly developing biomedical friendly materials in recent years. Among these biomaterials, polyhydroxyalkanoate (PHA) has been used to prepare nerve conduits, cartilage-promoting materials and auxiliary functional materials for esophagus regeneration due to its excellent properties. For example, because of its good biocompatibility and excellent physical, chemical and mechanical properties, poly-4-hydroxybutyrate (P4HB) in the PHA family has been used as a patch for the repair of human abdominal wall defects. The traditional polypropylene (PP) patch has better biocompatibility; but its disadvantage is that it is very expensive, and there are relatively few related products on the ma...

AI Technical Summary

Problems solved by technology

Medical grade PHA has also been initially obtained. However, due to the shortcomings of biological fermentation relative to the chemical process, the basic chemical parameters such as the molecular weight of the product are difficult to control. The subsequent purification process often contains cell membrane, cytoplasm residues, and certain intracellular toxins. , the obtained PHA raw material is not pure enough to realize industrialization

Therefore, the main problem at present is that the purity of most PHA raw materials is not high, the molecular weight distribution is wide, and the molecular weight dispersion is large; and the molecular weight is relatively large, which seriously limits its refined and functional applications.

[0007] In view of the low purity of PHB, the current common purification method is to dissolve the crude PHB in an organic solvent for purification.

Although this method can improve the purity of PHB, it needs to use toxic organic solvents (for example, other organic solvents such as chloroform, dichloromethane, dichloroethane or N-methylpyrrolidone), which not only cause harm to the environment , but also a threat to the health of the operating staff

Secondly, the traditional purification method requires multiple cycles of water washing, which consumes a large amount of pure water. At the same time, due to the many times of water washing, the yield of PHB is low, and the purification cost is further increased.

More importantly, the molecular weight distribution of purified PHB is still relatively broad, making it impossible to refine and functionalize it

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