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Glutamate is the product of the first amino acid in the world. Temperature is one of the main parameters of the glutamic acid fermentation control, breeding high temperature glutamate strain, helps to reduce energy consumption maintain fermentation temperature glutamic acid production process increase the economic benefits of the MSG production. In this paper, glutamic acid producing bacteria the genome shuffling breeding high temperature, after many rounds of reorganization, screening mutant enhanced temperature performance, and an F343 fermentation performance for a preliminary study. 9 glutamic acid producing bacteria collected in this laboratory, the temperature characteristics and acid production characteristics elect SW07-1 and SW07-2 for the original strain. Bacterial logarithmic growth in the early (5 h) strain age are used for mutagenesis, UV irradiation 5 min, or the concentration of 1.0% (v / v) of the DES treatment 30 min, or X-ray irradiation 35 min. SW07-1 is obtained by X-ray, UV, DES mutation, Filter 5 temperature resistance is slightly enhanced, and 38 ℃ fermentation glutamic acid production is relatively positive mutants: SW07-1-1, SW07-1 -2, SW07-1-3, SW07-1-4, SW07-1-5; SW07-2 after UV, DES mutagenesis and screened three heat resistance and acid production enhanced mutant SW07-2-1 , SW07-2-2, SW07-2-3. Protoplast preparation inactivated mark and fusion conditions. Draw SW07-1, SW07-2 bacterial penicillin sodium concentration of pre-treatment, 0.2 U / mL, and the treatment time 2 h and 1 h, respectively, the lysozyme concentration was 1.0 mg / mL, the enzymatic hydrolysis at 37 ° C for 15 h protoplast . Protoplast UV inactivation time of 30 min, 60 ° C heat inactivation time of 120 min. Protoplast fusion conditions for PEG6000 concentration of 35%, of fusion temperature 32 ° C, the fusion time 30 min, the fusion rate was 2.6 × 10-5. A, B are two different processes of genome shuffling. A process, SW07-1-1, SW07-1-2, SW07-1-3, SW07-1-4, SW07-1-5 as the starting bacterial library screening by two reorganization get better performance 5 the restructuring of the strains, the average high temperature 38 ℃ acid production than the starting parent strain (SW07-1) 37% increase; process B, SW07-1-1, SW07-1-2, SW07-2-1 , SW07-2-2, SW07-2-3 as the starting bacterial library, after the reorganization of the three screening to get the five better performance reorganization strains, the average acid production in the next 38 ℃ (56.5 g / L) wherein F343 yield increased by 66% higher than the starting parental strain (SW07-1). Fermentation performance of the preliminary study on the restructuring of the bacteria F343, F343 35 ℃ -41 ℃ temperature fermentation, glutamic acid production and cell concentration than the original strain SW07-1 high. By the concentration of corn syrup and the initial complement sweetened shake flask test strain F343 fermented at 38 ℃ 40 h acid production reached 78 g / L, the conversion rate of up to 55%.
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