Method of co-catalytically synthesizing various saccharic acids by virtue of synergism of metal ions and selective regulation whole-cell

Abstract

The invention discloses a method of co-catalytically synthesizing various saccharic acids by virtue of the synergism of metal ions and a selective regulation whole-cell, and relates to the technical field of synthesizing the saccharic acids by biologically catalyzing sugar. The method is mainly characterized in that in a mixed sugar solution or lignocelluloses hydrolysate containing glucose and xylose, 1g/L to 10g/L of gluconobacter oxydans is used as a biological catalyst to co-catalyze the glucose and the xylose under an oxygen-supply condition so as to synthesize the saccharic acids. Metal salt of a given concentration containing zinc ions and trivalent iron ions is added so as to selectively inhibit the catabolism of a cell on the gluconic acid, but a dehydrogenation catalytic reaction of the xylose and the glucose is hardly affected, thus an effect of the cell for co-catalyzing and high-efficiently synthesizing a gluconic acid (salt) and xylonic acid (salt) product can be further achieved, and the reaction time is effectively shortened. By adopting the method, the utilization rate of the glucose and the xylose reaches 100 percent, and the yield of the gluconic acid is more than 70 percent, and the yield of the xylonic acid is more than 92 percent, and the total concentration (mass concentration) of the product gluconic acid (salt) and xylonic acid (salt) can be more than 30 percent.

Description

1. Technical field [0001] The invention relates to the technical field of biologically catalyzing the synthesis of sugar acids from sugars, in particular to a method for co-catalyzing and synthesizing various sugar acids in whole cells through selective regulation of metal ions. 2. Background technology [0002] Gluconic acid and xylonic acid, as polyhydroxy organic acids, can be used as food, feed additives, cement superplasticizers, dispersants, slow-release agents, concrete adhesives, plasticizers, glass cleaners, metallurgical removers, etc. Rust agent, metal ion chelating agent, textile bleaching aid, pesticide suspending agent, tanning agent and water stabilizer, etc., are widely used in food, medicine, feed breeding, chemical industry and environmental protection and other industries. The preparation and production methods of sugar acid mainly include chemical methods and biological methods. The chemical methods generally require the use of inorganic catalysts, harsh ...

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Problems solved by technology

However, in a reaction system where multiple sugar components coexist, Gluconobacter oxidans preferentially and rapidly catalyzes the production of gluconic acid from glucose, and the biooxidation of other sugars including xylose will be inhibited to varying degrees by glucose, resulting in a delayed effect. At the same time, the gluconic acid produced will be rapidly and further catabolized by the cells and consumed in large quantities, which will eventually cause a serious loss of gluconic acid product yield (ZhouXin, et al, Bioresources, 2015; ZhouXin, et al, Biochemical Engineering Journal, 2015), so directly oxidize glucose Acidobacterium whole-cell catalysis of lignocellulose hydrolyzate is difficult to achieve the goal of synchronous and efficient synthesis of sugar and acid by co-catalysis of multiple sugar components

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