Domestication method for industrial saccharomyces cerevisiae

Abstract

The invention provides a domestication method for industrial saccharomyces cerevisiae capable of resisting fermentation inhibitors, resisting high temperature and resisting high-concentration ethanol.The domestication method comprises the following steps: carrying out two-stage domestication on saccharomyces cerevisiae, wherein in first-stage domestication, when the content of ethanol in fermenting mash reaches high concentration ( greater than 12% (v / v)), the fermenting mash is replaced by fresh liquefied mash for keeping fermentation, the replacement is carried out for 20 times at least, and the time interval of the replacement is 20-30 hours, in second-stage domestication, except for replacement of the fermenting mash for multiple times, a first-stage domestication strain is domesticated at a high temperature by a temperature gradient, and the temperature is increased by 0.5-2 DEG C every 18-24 times of replacement. The domesticated saccharomyces cerevisiae not only adapts to fermenting conditions of a factory and resists an inhibitor of a fermentation substrate, but also keeps high ethanol production ability, efficient reproduction metabolism is still implemented in an environment at a high temperature, and therefore, the ethanol fermenting level of an enterprise can be increased on the premise of not changing process routes and conditions.

Description

technical field [0001] The invention belongs to the fields of bioengineering and microorganisms, and in particular relates to a domestication method of Saccharomyces cerevisiae which is resistant to inhibitors in the industrial fermentation process of ethanol, high-concentration ethanol and high temperature. Background technique [0002] Ethanol is an important raw material in the food and chemical industries, and also an oxygen-containing additive in motor gasoline. my country's ethanol fermentation production mainly uses corn, cassava, wheat, rice and other starchy crops as raw materials, and uses yeast for fermentation to produce. The ethanol fermentation process 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, saccharification, fermentation, ...

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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