Method for fermentation co-production of PDO,BDO and PHP by constructing gene engineering strain

Abstract

A method for constructing genetic engineering bacteria used in the fermentation and the coproduction of PDO, BDO and PHP belongs to the biochemical technical field. The process of the method comprises the following steps that: D-type lactate dehydrogenase gene is removed from wild fungus used for generating PDO, and coenzyme A dependent aldehyde dehydrogenase and polyhydroxy fatty acid synthase gene are introduced so as to construct genetic engineering bacteria used in the fermentation and the coproduction of PDO, BDO and PHP; aerobic fermentation and a fermentation adjust and control mode according to which glycerol and an alkali solution undergo mixing fed batch are adopted; and a product extraction flow during which fermentation broth undergoes membrane filtration, electrodialysis, concentration and rectification steps so as to separate the products of PDO, BDO and PHP. The method has the advantages that: the constructed genetic engineering bacteria can produce PDO, BDO and PHP at the same time, thereby increasing the utilization rate of raw materials and reducing production cost; meanwhile, the synthesis of byproduct lactic acid is reduced, and an after-extraction process is simplified so as to reduce extraction cost; moreover, the method increases the synthesis of thalli NADH2 while introducing PHP.

Description

technical field [0001] The invention belongs to the field of biochemical technology, and in particular provides a method for constructing genetically engineered bacteria to ferment and co-produce PDO, BDO and PHP; the PDO is the abbreviation of 1,3-propanediol, and the abbreviation of BDO is 2,3-butanediol , PHP is a polymer (poly-β-hydroxypropionic acid) produced by the polymerization of β-hydroxypropionic acid as a monomer. Background technique [0002] 1,3-Propanediol (PDO for short) is an important chemical raw material, which can be used as an organic solvent in ink, printing and dyeing, paint, lubricant, antifreeze and other industries. The main use of PDO is as a monomer for the synthesis of polyester and polyurethane, especially polytrimethylene terephthalate (PTT) produced by polymerization with terephthalic acid, which shows a higher ratio than 1,2-propanediol and butanediol Polymers synthesized from alcohols and ethylene glycol as monomers have better performance...

AI Technical Summary

Problems solved by technology

Under anaerobic conditions, 5g / L glucose was used as the carbon source, and the medium supplemented with vitamin B12 was also fermented, but no PDO was detected in the fermentation broth after 48 hours of cultivation

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