High production method for glycerol with multi-step zymotechnics

Abstract

Disclosed is a high-yield method for using a multi-step fermentation method to manufacture glycerin, which belongs to the technical field of biochemical industry. Through adjusting the ventilation capacity and the rotating speed, the fermentation can be divided into four stages for staged-fermentation with the process steps: a hyperosmotic yeast starter liquid which accounts for 5 to 10 percent of the inoculation amount according to the volume is added into an initial fermentation medium containing 250 g / l to 380 g / l glucose concentration, and the aerobic fermentation is performed under the condition of 30 DEG C to 40 DEG C; the ventilation capacity is turned up every 6 hours to finally reach 0.6 vvm to 3.5 vvm, the stirring rate reaches 70 rpm to 600 rpm, when the glucose concentration is lower than 30 g / l to 50 g / l, the multi-step fermentation enters the third stage of fermentation, when the ventilation capacity is turned down every 4 hours to 6 hours to finally reach 0 vvm, the stirring rate reaches 10 rpm to 50 rpm, the multi-step fermentation enters the forth stage of anaerobic fermentation, and when the glucose concentration is lower than 2 g / l, the fermentation stops. After the fermentation is finished, the fermentation liquor undergoes solid-liquid separation, and the glycerin is prepared into products through separation and purification. The invention has the advantages that the residual sugar is obviously reduced at the later stage of fermentation, and the glycerin is not re-consumed.

Description

technical field [0001] The invention belongs to the technical field of biochemical industry, and in particular relates to a high-yield method for producing glycerol by a multi-step fermentation method. Background technique [0002] Glycerol, namely glycerol, is an important polyhydric alcohol, which is widely used in toothpaste, tobacco, cosmetics, paint industry and other industries. It is known that glycerin is directly or indirectly used as raw material in the production of more than 1700 products. The production methods include chemical synthesis, oil saponification hydrolysis and microbial fermentation. When the glycerin produced by the first two methods cannot meet the market demand, people focus on the research on the production of glycerin by microbial fermentation. Among them, the most researched It is the fermentative production of hyperosmotic yeast. It has proposed technologies such as fed-batch, continuous production and cell immobilization. Wuxi Institute of Li...

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Problems solved by technology

[0002] Glycerol, namely glycerol, is an important polyhydric alcohol, which is widely used in toothpaste, tobacco, cosmetics, paint industry and other industries. It is known that glycerin is directly or indirectly used as raw material in the production of more than 1700 products. The production methods include chemical synthesis, oil saponification hydrolysis and microbial fermentation. When the glycerin produced by the first two methods cannot meet the market demand, people focus on the research on the production of glycerin by microbial fermentation. Among them, the most researched It is the fermentative production of hyperosmotic yeast. It has proposed technologies such as fed-batch, continuous production and cell immobilization. Wuxi Institute of Light Industry and Institute of Chemical Metallurgy, Chinese Academy of Sciences jointly undertake the special task of "production of glycerol by fermentation" (Zhuge Jian, Fang Huiying , production of glycerin by microbial aerobic fermentation, Fine and Specialty Chemicals, 2001-20: 22-23), the average fermentation level reached: glycerin content 106.9g / l, sugar conversion rate reached 50.39%; but the production of glycerol by fermentation The technical "bottleneck" of the industrialization of the process lies in the extraction of glycerol (P.kishore, Concentration of Glycerol in Fermentation Baths by Reverse Osmosis, J.Microbio, Biotechnol, 1987, 2(1): 22-27), because in the later stage of fermentation, The sugar consumption rate of the cells decreased, and although the residual sugar concentration in the fermentation broth was still at a certain level, glycerol was consumed by the cells (Liu YQ, Liu DH, Su Q, Xie DM, Glycerol production by Candida krusei employing NaCl as an osmoregulator in batch and continuousfermentations., Biotechnol Lett 2002, 24: 1137-1140)

The fermentation was forced to stop, which not only affected the final yield of glycerin, but also when the glycerin was distilled and extracted, the excessively high concentration of residual sugar was easy to coke and foul at high temperature, making glycerin distillation very difficult or even impossible; for this reason, people successively Propose resin adsorption method, carrier distillation method (Zhuge Jian, Chinese patent, application number: 89103615), residual sugar oxidation method (Cai Shuihong, Chinese patent, application number: 94112202.6), solvent extraction (Cai Shuihong, Chinese patent, application number: 94112180.1 ) and other methods. The starting point of these methods is the same. It is not to reduce residual sugar through fermentation process optimization or strain selection, but to try to separate residual sugar and glycerin after the fermentation is stopped. Although it has a certain effect, it is affected by Both technical and cost constraints are not ideal