Method for synthesizing tagatose from cyanobacteria

Abstract

The invention relates to a method for synthesizing tagatose from cyanobacteria. The method comprises the following steps: 1), firstly, according to an NSI gene of cyanobacteria Syn7942, constructing an integrated vector NSI, and then inserting HXK, FbaA and phytase genes into the vector NSI to obtain a required recombinant vector NSI-HFP; 2), transforming the vector NSI-HFP into cyanobacteria Syn7942 cells, and then preliminarily screening out monoclonal transgenic cyanobacteria Syn7942 through a chloramphenicol solid culture medium; 3), transferring the screened monoclonal transgenic cyanobacteria Syn7942 to a liquid culture medium with chloramphenicol resistance, and extracting a cyanobacteria genome for PCR verification of a target gene; 4), culturing the monoclonal transgenic cyanobacteria Syn7942 under a proper condition, and adding IPTG for inducing expression of the HXK, FbaA and phytase genes, and synthesizing the tagatose by enzymes by using fructose produced by photosynthesisof the cyanobacteria as a substrate; 5), performing separation and purification. By the method, when the tagatose is synthesized through transformation of the cyanobacteria as substrate organisms, only sunlight and moisture and the like are required as production raw materials, production equipment and a production environment are easy to construct, and the production cost is greatly reduced.

Description

technical field [0001] The invention relates to a synthesis technology of tagatose, in particular to a method for producing tagatose by using cyanobacteria, belonging to the field of synthetic biology. Background technique [0002] Cyanobacteria (Cyanobacteria) is a type of bacteria that obtain energy through photosynthesis, also known as blue-green algae, blue-green bacteria or cyanobacteria. Chloroplastin makes it appear blue-green. Cyanobacteria are the earliest algae that appeared on the earth. They are the simplest and most primitive single-celled organisms. Simple photosynthesis unit. [0003] Due to the unique physiological characteristics of cyanobacteria capable of photosynthesis, many scientists regard cyanobacteria as a "biological photoreactor", through which carbon dioxide and water in the air can be converted into chemical products and some high-value natural products needed by humans. . Genetic modification of cyanobacteria to biosynthesize these products ...

AI Technical Summary

Problems solved by technology

[0005] At present, the synthesis methods of tagatose are mainly chemical catalysis synthesis method and biotransformation method. The chemical catalysis synthesis method uses galactose as raw material, through metal hydroxide (usually Ca (OH) CaCl2) catalyzes galactose to generate tagatose-Ca complexes, and then releases tagatose from the complexes through acid neutralization. This method has the advantages of expensive raw materials, chemical pollutants, and many by-products under alkaline conditions. Difficult to separate and many other disadvantages

The biotransformation method uses L-arabinose isomerase to convert galactose into tagatose, but the same reaction has the disadvantages of expensive raw materials, low conversion efficiency, and difficult product separation, making it difficult to realize large-scale industrial production.

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