Method for efficiently producing L-proline

Abstract

The invention discloses a method for efficiently producing L-proline, and belongs to the technical field of fermentation engineering. In the method provided by the invention, a DO-stat method is adopted to maintain the glucose concentration at a relatively low constant level, thus effectively eliminating a repression effect of glucose in a fermentation production process of L-proline; and comparedwith a batch fed fermentation process, the method can increase the average yield of L-proline from 77.4g / L to 84.3g / L, and the average production intensity from 1.84g / L.h to 2.11g / L.h, so that the method has a good industrial application prospect.

Description

technical field

[0001] The invention relates to a method for efficiently producing L-proline, which belongs to the technical field of fermentation engineering. Background technique

[0002] L-proline is a neutral amino acid containing an imino group, and one of the 20 basic amino acids that make up proteins. It is a non-essential amino acid for the human body. L-proline has a certain physiological activity, and has a wide range of uses in medicine, agriculture, chemical industry and food, etc., especially in medicine, it is an intermediate in the synthesis of many new drugs.

[0003] At present, the industrial production of L-proline mainly adopts fermentation method. In the fermentation production process of L-proline, the intermittent feeding process is usually used to eliminate the inhibition of high concentration glucose on the synthesis of L-proline; however, the intermittent feeding process is easy to cause drastic changes in the glucose concentration, causing Change...

Examples

Embodiment 1

[0049] Embodiment 1: batch fermentation (DO is controlled at 10%) based on DO-stat feeding control strategy

[0050] The starting condition of the fermenter is the same as that of intermittent fed-batch fermentation. When the DO rises to 10%, the glucose is fed, and the DO-related feeding is controlled. Whenever the DO is higher than 10%, a short feeding is performed to maintain the dissolved oxygen at About 10% (the feeding liquid composition is 500g / L glucose), ferment for 58h, and detect the average yield and production intensity of L-proline.

[0051] The test results are: the average output of L-proline is 56.2g / L, and the production intensity is 0.97g / L·h.

Embodiment 2

[0052] Embodiment 2: Batch fermentation (DO is controlled at 20%) based on DO-stat fed-batch control strategy

[0053] The starting condition of the fermenter is the same as that of intermittent fed-batch fermentation. When the DO rises to 20%, the glucose is fed, and the DO-related feeding is controlled. Whenever the DO is higher than 20%, the fed-batch is carried out for a while to maintain the dissolved oxygen. At about 20% (the feed liquid composition is 500 g / L glucose), ferment for 58 hours, and detect the average yield and production intensity of L-proline.

[0054] The test results are: the average output of L-proline is 58.6g / L, and the production intensity is 1.00g / L·h.

Embodiment 3

[0055] Embodiment 3: batch fermentation (DO is controlled at 25%) based on DO-stat fed-batch control strategy

[0056] The starting condition of the fermenter is the same as that of intermittent fed-batch fermentation. When the DO rises to 25%, it starts to feed glucose, and controls DO-related feeding. Whenever DO is higher than 30%, it will be fed for a while to maintain dissolved oxygen. At about 30% (the feed liquid composition is 500 g / L glucose), ferment for 57 hours, and detect the average yield and production intensity of L-proline.

[0057] The test results are: the average output of L-proline is 61.5g / L, and the production intensity is 1.08g / L·h.

technical field

[0001] The invention relates to a method for efficiently producing L-proline, which belongs to the technical field of fermentation engineering. Background technique

[0002] L-proline is a neutral amino acid containing an imino group, and one of the 20 basic amino acids that make up proteins. It is a non-essential amino acid for the human body. L-proline has a certain physiological activity, and has a wide range of uses in medicine, agriculture, chemical industry and food, etc., especially in medicine, it is an intermediate in the synthesis of many new drugs.

[0003] At present, the industrial production of L-proline mainly adopts fermentation method. In the fermentation production process of L-proline, the intermittent feeding process is usually used to eliminate the inhibition of high concentration glucose on the synthesis of L-proline; however, the intermittent feeding process is easy to cause drastic changes in the glucose concentration, causing Change...

Examples

Embodiment 1

[0049] Embodiment 1: batch fermentation (DO is controlled at 10%) based on DO-stat feeding control strategy

[0050] The starting condition of the fermenter is the same as that of intermittent fed-batch fermentation. When the DO rises to 10%, the glucose is fed, and the DO-related feeding is controlled. Whenever the DO is higher than 10%, a short feeding is performed to maintain the dissolved oxygen at About 10% (the feeding liquid composition is 500g / L glucose), ferment for 58h, and detect the average yield and production intensity of L-proline.

[0051] The test results are: the average output of L-proline is 56.2g / L, and the production intensity is 0.97g / L·h.

Embodiment 2

[0052] Embodiment 2: Batch fermentation (DO is controlled at 20%) based on DO-stat fed-batch control strategy

[0053] The starting condition of the fermenter is the same as that of intermittent fed-batch fermentation. When the DO rises to 20%, the glucose is fed, and the DO-related feeding is controlled. Whenever the DO is higher than 20%, the fed-batch is carried out for a while to maintain the dissolved oxygen. At about 20% (the feed liquid composition is 500 g / L glucose), ferment for 58 hours, and detect the average yield and production intensity of L-proline.

[0054] The test results are: the average output of L-proline is 58.6g / L, and the production intensity is 1.00g / L·h.

Embodiment 3

[0055] Embodiment 3: batch fermentation (DO is controlled at 25%) based on DO-stat fed-batch control strategy

[0056] The starting condition of the fermenter is the same as that of intermittent fed-batch fermentation. When the DO rises to 25%, it starts to feed glucose, and controls DO-related feeding. Whenever DO is higher than 30%, it will be fed for a while to maintain dissolved oxygen. At about 30% (the feed liquid composition is 500 g / L glucose), ferment for 57 hours, and detect the average yield and production intensity of L-proline.

[0057] The test results are: the average output of L-proline is 61.5g / L, and the production intensity is 1.08g / L·h.

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