Strain and method for producing hydroxytyrosol

Abstract

The invention discloses a strain and a method for producing hydroxytyrosol, and belongs to the technical field of bioengineering. According to the present invention, the recombinant cell for expressing the omega-transaminase, the alanine dehydrogenase and the alcohol dehydrogenase is constructed, and the appropriate RBS strength is adjusted, such that the efficiency of the recombinant escherichia coli cell for catalyzing the dopamine to synthesize the hydroxytyrosol is improved, the yield of the hydroxytyrosol after the reaction for 24 h can achieve 146 g / L, and the good industrial application prospect is provided.

Description

technical field [0001] The invention relates to a strain and a method for producing hydroxytyrosol, belonging to the technical field of microbial genetic engineering. Background technique [0002] Hydroxytyrosol, a natural antioxidant, is considered to be one of the most effective natural antioxidants known, mainly derived from olive oil. Traditional olive oil has been regarded as a very sacred food in Europe because of its various beneficial effects on human replacement. Later, scholars researched that the main components of its efficacy were tyrosol and hydroxytyrosol. And around 2012, hydroxytyrosol was approved by EC Regulation 432 / 2012 as an important part of "healthy olive oil polyphenols", and stipulated that the content of hydroxytyrosol and its derivatives in olive oil should be greater than 5mg / 20g. Due to its many benefits, hydroxytyrosol has been given the name of the supernutrient. [0003] In the prior art, the preparation of hydroxytyrosol is mainly extracte...

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Problems solved by technology

[0004] Plant extraction uses oleuropein as raw material, which is extracted from the waste of olive oil production. However, due to the complexity and low content of the extracted raw materials, the cost is high, the purity of the obtained hydroxytyrosol is low, and there are differences between batches. Issues of variance and seasonality

[0005] Since 1949, For the first time, 3,4-dihydroxyphenylacetic acid was used to chemically synthesize hydroxytyrosol, but the catalyst lithium aluminum hydride used was poor in stability, and the cost of the substrate was high, which led to obstacles in industrialization ( β-(3,4-Dioxyphenyl)- Justus Liebigs Annalen der Chemie.1949;563(1):86-93.)

In 2018, Ziosi and others used catechol and glyoxal dimethyl acetal to synthesize hydroxytyrosol. Although catechol has a wide range of sources, the cost of glyoxal dimethyl acetal is not low. In the process of two-step reduction, heavy metal palladium was used to catalyze (ATtwo-Step Process for the Synthesis of Hydroxytyrosol.ChemSusChem.2018; 11(13):2202-10). Chinese patent document CN201611249898.1 utilizes 3,4-dimethyl Oxyphenethyl alcohol is used as a raw material to demethylate the preparation of hydroxytyrosol, but the raw material cost is higher

Chinese patent document CN202110546281.0 transfers HpaB derived from Pseudomonas aeruginosa and HpaC from other specific sources in Saccharomyces cerevisiae capable of high tyrosol production. Inefficient expression in , resulting in a lower yield of 1120 mg / mL of hydroxytyrosol in Saccharomyces cerevisiae

Chinese patent document CN201711054680.5 uses tyrosine as a substrate to produce hydroxytyrosol by overexpressing aminotransferase, ketoacid decarboxylase, alcohol dehydrogenase, and hydroxylase in Escherichia coli. The enzyme does not provide enough amino acceptors, and the activity of hydroxylase is too low, and the soluble expression of the inventive protein is poor, resulting in a low final yield of hydroxytyrosol, which is 1469±56mg / mL

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