Electron Beam Mutation Breeding Of High Efficiency Lactobacillus For Degrading Nitrite

Lactic acid bacteria have effect on nitrite degradation, in this paper a lactic acid bacterium-- for example, to study the traditional pickle nitrite degradation effect. The main research contents are as follows:(1) First of all from the market to buy vegetables as bacteria source, in the separation of culture medium, selection of clear yellow discoloration circle colony.(2) Firstly, gram reaction and microscopic examination of selected strains, gram reaction to blue, short rod, in pairs, single, chain appear less strain on separation plate, white, opaque, round and smooth, dense breeding colonies and it can be observed that the single colony calcium circle. Preliminary identification of these properties of Lactobacillus plantarum. The microscopic examination of the colony to physiological and biochemical identification and sugar fermentation experiment, selected has the following characteristics: the strain catalase reaction is negative, that is "-"; the nitrate reduction reaction is negative, that is "-"; gelatin liquefaction test reaction is negative, that is "-"; in litmus milk the reaction of acid producing, expressed as "+"; the oxidation of glucose fermentation reaction is negative, that is "-"; in sports exercise test, expressed as "-". The last step in the strains were identified in seven leaf glucoside and carbohydrate fermentation test, the results were positive, said "+".(3) Mutation breeding of Lactobacillus plantarum using electron accelerator. Mutagenic dose for 1.22kGy、2.13kGy、3.01kGy、4.28kGy、5.35kGy、6.01kGy、7.01kGy、8.12 k Gy、9.23 kGy,The strength of the current is 1A, irradiation time was 5S, dosage is less than 3.01 kGy, the effect of degrading nitrite increased gradually; At the dose of 3.01 kGy, 4.28 kGy, mutation of 5.35 kGy in this interval, the amount of nitrite degradation tends to be stable; the dosage is more than 5.35 kGy, the ability of strains to degrade nitrite decreased significantly, at about 9.23 kGy, the ability of strains to degrade nitrite almost no; The current intensity of 1A, 2A, 3A, 4A, 5A, 6A, 7A, 8A, 9A, 10 A, mutation dose was 1.22 kGy, irradiation time is 5S, found in the strength of the current is less than 4A, the effect of nitrite degrading strain gradually increased; in 4A, 5A, the 6A interval in the strength of the current. The degradation rate of nitrite in steady; mutagenic dose is more than 6A, the ability of strains to degrade nitrite decreased significantly; in the C experiment, the mutation time was 2S, 4S, 6S, 8s, 10 s, 12 s, 14 s, 16 S, 18 S, 20 s, mutation dose was 1.22 kGy, the strength of the current is 1A. Now the induction time is less than 10 s, the effect of degradation of nitrite bacteria increased gradually; in 10 s, 12 s, 14 s in the range of current intensity, the amount of nitrite degradation tends to be stable; the dosage is more than 14 s, the ability of degrading nitrite decreased significantly. Then take the mutation dose was 2.13 kGy, 3.01 kGy, 4.28 kGy, current intensity is 4A, 5A, 6A, mutation time was 10 s, 12 s, 14 s were studied by orthogonal test, the results showed: in the induction time is 14 s, dosage is 2.13 kGy, the strength of the current is 4A, degrading nitrite mutagenesis are the strongest.(4) Methods using a laboratory preserved pickled cabbage, divided into three groups: control group, non induced bacteria group, bacteria group, 10 d fermentation time, inoculation amount was 5%, the first pH brine for 3, fermentation was carried out at a constant temperature of 25 DEG C under the. The results show that: the blank group sauerkraut fermentation, the production process, the nitrite content was first increased and then decreased, the nitrite content in fermented for fourth days, reached the maximum value, until the end of the 2-3D, almost not detected sub pin acid salt. Inoculation fermentation in the two groups, no significant high, nitrite content remained at a low level, almost not detected by nitrite bacteria to ferment for fifth days, and the induced bacteria to ferment for fourth days group content of nitrite is almost zero.(5) The mutant strains as experimental strain, set different inoculation quantity, different pH and different temperature test. Experiments show that: in the reasonable range, more suitable conditions for the degradation of nitrite by Lactobacillus plantarum inoculation amount was 5%, pH was 3, the temperature is 30 degrees centigrade.