Two-stage feeding type high-density method for fermenting and synthesizing polyhydroxy benzene alkyl acid ester

Abstract

The invention discloses a two-stage feeding type high-density method for fermenting and synthesizing polyhydroxy benzene alkyl acid ester, which comprises the following steps of: (1) a first stage: adding benzene-containing organic matter into a fermenting culture medium, adding pseudomonas putida seed liquid to culture in a fermenting way, controlling the rotate speed of a fermenting pot to be 150-180 rotation / min, the fermenting temperature to be 30+ / -20 DEG C, and the pH value to be 7.0+ / -0.3, and feeding carbon source when dissolved oxygen concentration and pH value simultaneously raise; and (2) a second stage: after the light-absorption density of microbial cell reaches 30, adjusting the pH value, simultaneously performing nitrogen limitation and oxygen limitation, and feeding the carbon source when the dissolved oxygen concentration and the pH value simultaneously raise, so that the carbon source in the fermenting liquid can be transferred to be the polyhydroxy benzene alkyl acid ester by means of anabolism with microbe. The method has the advantages of higher speed for metabolizing benzene-containing organic matter with the microbe, less function for inhibiting cell growth by the organic carbon source, and higher final cell concentration and product concentration thereby.

Description

technical field [0001] The invention belongs to the technical field of fermentation engineering, and in particular relates to a method for synthesizing polyhydroxybenzoic acid esters by two-stage fed-batch high-density fermentation. Background technique [0002] Polyhydroxyalkanoate has excellent characteristics such as biodegradability, biorenewability, biocompatibility and non-toxicity of degradation products, so that it can be used as a sustained-release drug carrier, surgical suture, artificial blood vessel, artificial bladder , artificial heart valve and other materials and their related applications. However, most of the polyhydroxyalkanoates used are polyhydroxybutyric acid or copolymers of hydroxybutyric acid and hydroxyvaleric acid, which do not contain functional groups like phenyl groups. Recently, clinical medical research has shown that organic compounds containing phenyl functional groups, such as phenylacetic acid and phenylbutyric acid, have anti-tumor, anal...

AI Technical Summary

Problems solved by technology

However, when microorganisms are used to synthesize polyhydroxyalkanoate containing phenyl functional groups with benzene-containing organic matter (such as valeric acid, phenyllactic acid, etc.) It has obvious inhibitory effect on cell growth and other reasons, so that the final cell concentration (less than 2 grams per liter) and product concentration (less than 1 gram per liter) are very low, losing the prospect of industrialized large-scale production

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