Low power microwave irradiation process for breeding lactic acid bacteria

Abstract

The low power microwave irradiation process for breeding lactic acid bacteria includes the following steps: 1. activating culture of bacterial seed; 2. centrifuging and washing with sterilized water; and 3. low power microwave irradiation while cooling with circular water to obtain low power microwave irradiation mutated bacterial strain. The process has thermal lethal rate of bacterial strain in 50-80 %, and mutation rate over 99 %, and is simple, low in cost and safe in operation.

Description

technical field [0001] The invention relates to a breeding method. Background technique [0002] Mutation breeding is an important and effective technique for most industrial microorganisms. Genetic engineering breeding is relatively complicated, and it is still difficult to be widely used like mutation breeding; chemical mutagenesis is widely used, and these mutagens are highly toxic to cells. Subject to certain restrictions; physical mutagenesis is widely used at home and abroad are ultraviolet rays, x-rays and gamma rays. With repeated use of these mutagens, many industrial strains have developed resistance to them. Microwave irradiation technology has just been introduced and applied to the breeding of lactic acid bacteria, but due to the thermal effect of microwaves, the temperature of the strains rises in a short period of time, the thermal lethality rate reaches 98-99%, and the gene mutation rate is low. Contents of the invention [0003] The purpose of the prese...

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Problems solved by technology

[0003] The purpose of the present invention is to solve the problems that microwave irradiation causes the strain temperature to rise in a short period of time in the breeding of lactic acid bacteria, the heat lethality rate is high, and the gene mutation rate is low, and a kind of low-power microwave irradiation lactic acid bacteria breeding method is provided It can be achieved through the following steps: (1) the bacterial strain is activated by the freeze-dried strain activation method, and then put into the liquid culture medium for 24-30 hours; (2) in the sterile room, take 9-11 mL from the liquid culture medium Transfer the bacterial suspension into a 20mL sterile centrifuge tube, then centrifuge at a speed of 3000-3500 rpm, and wash 2-3 times with sterile water, centrifuging for 10-15 minutes each time; (3) Take 9-12mL after washing Transfer the bacterial suspension into a test tube, put the test tube containing the bacterial suspension into a device with water circulation cooling at room temperature, and use low-power microwave irradiation, the frequency of low-power microwave irradiation is 2450MHz, and the power is 325~ 380W for 12-15 minutes to obtain low-power microwave irradiation mutagenic strains

The invention irradiates the bacteria under the condition of low power, and adopts water circulation cooling, which overcomes the problem of high thermal lethality in a short time when irradiated with high power

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