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Views: 0 Author: Site Editor Publish Time: 2022-08-17 Origin: Site
The industrial production technology of vitamin C has gone through three stages: concentration extraction method, chemical synthesis method and biological fermentation method.
At present, the industrial production of vitamin C all adopts the "two-step biological fermentation method" developed in my country in the 1970s. The method was jointly developed by the Institute of Microbiology of the Chinese Academy of Sciences and Beijing Pharmaceutical Factory, and high-efficiency strains were screened from more than 5,000 strains to achieve L-sorbose to 2-keto-L-gulonic acid (using it as a substrate, after The biotransformation of synthetic vitamin C after esterification, instead of the original chemical transformation process, saves a lot of toxic and harmful reagents, and greatly reduces the production cost. It is the only method currently used in industrial production.
The outstanding feature of the two-step bio-fermentation method of vitamin C is that the second-step fermentation (bioconversion of L-sorbose to 2-keto-L-gulonic acid) is the mixed fermentation of two bacteria, one is acid-producing bacteria ( Common ketogenic coronobacter) has a complete invertase system, but it grows slowly when cultivated alone, and the fermentation efficiency is extremely low. The associated bacteria cannot produce coronic acid alone, but can provide guarantee for the growth and acid production of acid-producing bacteria, and become the dependent bacteria of acid-producing bacteria. Therefore, the second-step fermentation process of vitamin C is actually "companion-dependent mixed-bacteria fermentation".
In the mixed-bacteria fermentation process, the two bacteria compete fiercely in terms of nutrition and space, but it is extremely difficult to balance the respective needs of the two bacteria in the actual mixed-bacteria fermentation control. Low or even fermentation failure has seriously affected the efficient and stable operation of production, and is a technical bottleneck that hinders the further improvement of vitamin C fermentation efficiency.
In addition, my country's vitamin C fermentation industry discharges about 40,000 tons of waste gulonic acid mother liquor and about 120,000 tons of waste fungus residue. The chemical oxygen demand value of the waste coronic acid mother liquor is as high as 800,000-1,000,000 mg/L (about 2,000 times the COD value of domestic sewage) and the pH value is less than 1.0, which is difficult to treat; the COD value of the waste fungus residue reaches 100,000 mg/L, showing The sol state is difficult to precipitate. These two kinds of wastes have huge emissions and extremely high COD values. There is no effective resource utilization method before, which brings huge environmental protection pressure to enterprises and is another technical bottleneck problem that needs to be solved urgently in the vitamin C industry.
In response to the problem of concomitant dependence restricting the improvement of fermentation efficiency, the Shenyang Institute of Applied Ecology, Chinese Academy of Sciences, together with Northeast Pharmaceutical Group Co., Ltd. and Shenyang Agricultural University, spent more than ten years on the fermentation mechanism of vitamin C mixed bacteria, concomitant active substances, and key metabolic enzymes. , fermentation process regulation and other aspects of systematic in-depth research.
The interaction law and mechanism between the associated bacteria and the acid-producing bacteria in the mixed-bacteria fermentation were revealed at the molecular level, and the associated active substance was confirmed to be an acidic single-subunit protein of 36,000 Daltons. Further developed a simple and inexpensive preparation technology and process of concomitant active preparations. By adding concomitant active substances in a specific way to replace the concomitant bacteria, combined with the enzymatic catalysis dual-platform control method of sorbose→gulonic acid, the concomitant dependence was finally created for the first time. New technology and process of vitamin C fermentation for liberation of sex.
Compared with the traditional mixed-bacteria fermentation technology, the new fermentation technology increases the yield of colonic acid by 4.3 percentage points, shortens the fermentation cycle by 17.5%, saves raw materials and energy consumption by 16.4%, and increases the overall fermentation efficiency by 27%.
The results of the project have been applied in Northeast Pharmaceutical Group Co., Ltd. and achieved significant economic and environmental benefits.
The vitamin C waste bacteria residue is highly stable colloid, which is extremely difficult to precipitate and dry. The Shenyang Institute of Applied Ecology, Chinese Academy of Sciences has systematically studied the composition and characteristics of waste fungus residues, created high-temperature and normal temperature coagulation technology, successfully separated the bacterial protein and made it into feed protein/agricultural agent, and at the same time made the waste fungus residue COD emission reduction of 77%.
The waste mother liquor contains 25% gulonic acid, which is difficult to recycle due to the variety and quantity of impurities. The project team used the patented technology to make the coronic acid recovery rate up to 75% and make it into high value-added Vc-Na. The remaining residue after extraction is further developed into a new type of bio-fertilizer with improved crop yield, realizing 100% resource utilization of waste cologic acid mother liquor.
In a word, this project firstly created a new technology of vitamin C mixed bacteria fermentation to relieve the associated dependence, which greatly improved the overall efficiency of vitamin C industrial fermentation. Secondly, this project will turn the bulk waste of vitamin C into treasure, which will be used as feed and fertilizer for agricultural production, greatly reduce COD emissions, and promote the green and sustainable development of my country's vitamin C industry.
