A strain and application of black mold gene engineering projects and applications with high -yield organic acid under low -soluble oxygen conditions

Abstract

The present invention relates to a genetically engineered bacterial strain of Aspergillus niger with high organic acid production under low dissolved oxygen conditions. The construction steps of the genetically engineered bacterial strain are as follows: step 1, constructing a heterologously expressed vhb gene plasmid; the gene vhb sequence The fragment is controlled by the Aspergillus niger 3-glycerol phosphate dehydrogenase gene promoter PgpdA; step 2, the acquisition of the heterologous expression vhb gene strain, namely the Aspergillus niger (Aspergillus niger) genetically engineered strain with high organic acid production under low dissolved oxygen conditions. The present invention is based on the natural characteristics of Aspergillus niger to produce organic acids, and through genetic recombination to transform the physiological characteristics of Aspergillus niger, a genetically engineered strain of Aspergillus niger is obtained. Experiments have confirmed that the genetically engineered strain of Aspergillus niger can produce organic acids under low dissolved oxygen conditions. The acid ability is significantly improved, which provides excellent strains for the preparation of organic acids by microbial fermentation.

Description

technical field

[0001] The invention belongs to the technical field of genetic engineering, in particular to a genetically engineered strain of Aspergillus niger that is resistant to low dissolved oxygen conditions and produces high organic acid and its application. Background technique

[0002] As an important cell factory for the fermentative production of organic acids for more than 100 years, Aspergillus niger is not only a GRAS (generally regarded safe) strain, but also able to utilize cheap carbon sources. Citric acid and L-malic acid are currently the two most important organic acids in the food, pharmaceutical and other industries. In the market of all organic acids, citric acid has a market share of more than 70%, which can be used as a flavoring agent and an antioxidant for edible oils. At the same time, it improves the sensory properties of food, enhances appetite and promotes the digestion and absorption of calcium and phosphorus in the body. In the pharmaceuti...

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