Aspergillus niger strain efficiently producing malic acid, 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.

CN111218408AActive Publication Date: 2020-06-02南京昊禾生物科技有限公司
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2020-06-02

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Abstract

The invention relates to an Aspergillus niger gene engineering strain efficiently producing malic acid. The Aspergillus niger gene engineering strain is an Aspergillus niger gene engineering strain which knocks out a citric acid transporter gene cexA, and overexpresses a glucose transporter gene mstC, a hexokinase gene hxkA, a phosphofructokinase gene pfkA, and a pyruvate kinase gene pkiA which are derived from Aspergillus niger. The efficiency for producing malic acid of the Aspergillus niger gene engineering strain is significantly improved, the output on the eighth day through fed-batch fermentation in a fermentation tank reaches 195.72-210 g / L, a conversion rate of malic acid to glucose reaches 1.59-1.64 mol / mol, and a fermentation cycle is shorter by one day compared with a starting strain, namely the fermentation cycle is shortened from original 9 days to 8 days. An excellent strain for the preparation of malic acid by microbial fermentation methods is provided.
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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...