A kind of domestication method of industrial saccharomyces cerevisiae

Abstract

The invention provides a domestication method of Saccharomyces cerevisiae resistant to fermentation inhibitors, high temperature and high concentration ethanol. The domestication method of the present invention comprises two-stage domestication to Saccharomyces cerevisiae, wherein, the first-stage domestication is when the ethanol content in the fermented mash reaches a relatively high concentration (>12% (v / v)), using fresh liquefied mash to replace Ferment the mash and continue to ferment, the replacement is carried out at least 20 times, and the time interval of the replacement is 20-30 hours; the secondary acclimatization is to perform high temperature on the primary domesticated strain with a temperature gradient in addition to replacing the fermented mash multiple times. Acclimatization, wherein, every 18-24 times of replacement increases the temperature by 0.5°C-2°C. The domesticated Saccharomyces cerevisiae not only adapts to the fermentation conditions of the factory, tolerates the inhibitors of the fermentation substrate, but also maintains a high ethanol production capacity, and still efficiently reproduces and metabolizes in a relatively high temperature environment, so without changing the process route Under the premise of favorable conditions, the ethanol fermentation level of enterprises can be improved.

Description

technical field [0001] The invention belongs to the fields of bioengineering and microorganisms, and particularly relates to a method for domesticating Saccharomyces cerevisiae which is resistant to inhibitors in the industrial fermentation process of ethanol, is resistant to high-concentration ethanol and is resistant to high temperature. Background technique [0002] Ethanol is an important raw material for the food and chemical industries and an oxygen-containing additive for motor gasoline. my country's ethanol fermentation production mainly uses starchy crops such as corn, cassava, wheat, and rice as raw materials, and uses yeast for fermentation to produce. Ethanol fermentation is a process in which yeast uses fermentable sugars in the medium to produce alcohol and release carbon dioxide under suitable temperature and anaerobic conditions. The entire ethanol fermentation production process can be divided into raw material crushing, mixing, liquefaction, saccharificati...

AI Technical Summary

Problems solved by technology

The method adopted by the invention to gradually increase the concentration of the target fermentation substrate through repeated culture operations improves the tolerance of the yeast to the inhibitors in the target fermentation substrate, but due to the limited time for the yeast to acclimatize and cultivate in the mixture (only 8 -12 hours), the ethanol concentration produced in the domestication process is far less than industrial ethanol production, so this method cannot improve the tolerance of yeast strains to the high concentration of ethanol produced in industrial fermentation

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