A high-efficiency production of malic acid Aspergillus niger strain, construction method and application

A technology of Aspergillus niger and malic acid, applied in the field of microorganisms, can solve the problems of low production efficiency, high production cost, complex malic acid separation and purification process, etc., and achieve the effect of improving efficiency

CN111218408BActive Publication Date: 2021-05-04南京昊禾生物科技有限公司
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2021-05-04

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Abstract

The invention relates to a genetically engineered strain of Aspergillus niger that can efficiently produce malic acid. The genetically engineered strain of Aspergillus niger has knocked out the citric acid transporter gene cexA, and overexpressed the glucose transporter gene mstC and hexokinase derived from Aspergillus niger. Genetic engineering strain of Aspergillus niger with gene hxkA, phosphofructokinase gene pfkA and pyruvate kinase gene pkiA. The efficiency of producing malic acid by the genetically engineered strain of Aspergillus niger of the present invention is significantly improved, and the output of fed-batch fermentation in the fermenter on the eighth day reaches 195.72-210g / L, and the conversion rate of malic acid to glucose reaches 1.59-1.64mol / mol, The fermentation cycle was shortened by one day compared with the starting strain, from the original 9 days to 8 days. Excellent strains are provided for the preparation of malic acid by microbial fermentation.
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Description

technical field

[0001] The invention belongs to the technical field of microorganisms, in particular to an Aspergillus niger strain for efficiently producing malic acid, a construction method and application thereof. Background technique

[0002] As an important cell factory, Aspergillus niger has been used in the fermentative production of organic acids for more than 100 years. It is not only a GRAS (generally regarded safe) strain, but also able to utilize cheap carbon sources. L-malic acid, also known as 2-hydroxysuccinic acid, is mainly used in food, medicine and other industries. In the food industry, L-malic acid is mainly used as a food sour agent. Compared with citric acid, it has the characteristics of soft taste, high acidity, and long residence time. It does not damage the oral cavity and teeth, and does not accumulate fat. The safe food sour agent recognized by the international food industry is one of the organic acids with the largest amount and good developme...

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Embodiment Construction

[0075] The embodiments of the present invention will be described in detail below. It should be noted that the embodiments are illustrative, not restrictive, and cannot limit the protection scope of the present invention.

[0076] The raw materials used in the present invention, unless otherwise specified, are conventional commercially available products; the methods used in the present invention, unless otherwise specified, are conventional methods in the art.

[0077] A genetically engineered strain of Aspergillus niger (Aspergillus niger) that efficiently produces malic acid. The genetically engineered strain of Aspergillus niger has knocked out the citric acid transporter gene cexA, and overexpressed the glucose transporter gene mstC and hexose sugar derived from Aspergillus niger. Aspergillus niger genetic engineering strain with kinase gene hxkA, phosphofructokinase gene pfkA and pyruvate kinase gene pkiA.

[0078] Preferably, the gene cexA sequence is 4989494 in NCBI-Ge...