目的：选育出一株高产γ-聚谷氨酸（γ- polyglutamic ac

Objective: breeding a strain yield polyglutamic acid [gamma] (γ- polyglutamic acid, γ- PGA), and to optimize the fermentation medium. (. Bacillus sp X-1): a method to pre-screening laboratory Bacillus strain as starting, by chemical mutagens - Ultraviolet Mutagenesis binding complex skim milk through circle screened, and molecular biological identification; 24 using orifice response surface method for rapid strain fermentation medium optimized to determine the best formulation fermentation. Results: After 16s rDNA sequence analysis, X-1 strain was identified as Bacillus subtilis. After three chemical mutagens - composite UV mutagenesis, to obtain a high yield of γ-PGA mutant strain N-2, the production reached mutagenesis mutant 21.3g / L, 17.2% increase over the previous mutagenesis; PB by (Plackett- Burman, PB) test, screened three factors significantly affect yield γ- PGA: glucose, ammonium nitrate, and zinc sulfate; Approximation of steepest ascent maximum yield test area, the test using the Box-Behnken (Box-Behnken for Deign, BBD) optimization method, after verification 250ml conical flask fermentation, optimum fermentation medium was: glucose 37.88; 0.41 ammonium nitrate, zinc sulfate 0.14 40 sodium glutamate, yeast extract 8, dicalcium phosphate 2 potassium, magnesium sulphate 0.1, 0.02 Meng sulfate, final fermentation yield was 28g / L, 33.17% increase over the previous optimization. Conclusion: a porous plate method using response surface methodology can significantly accelerate screening, optimized for speed, reliable results.

Objective: To select a strain of high-yielding gamma-polyglugin (gamma-polyglutamic acid, gamma-PGA) and optimize its fermentation medium. Methods: The pre-screening of Bacillus spores (Bacillus sp. X-1) as the starting strain, by chemical mutaid-UV composite mutagenic combination degrease milk transparent ring method, and molecular biology identification; Results: After 16s rDNA sequence analysis, the strain X-1 was identified as Bacillus subtilis. After 3 chemical mutants - UV composite mutagenic, a high-yielding strain of gamma-PGA mutation N-2, after the mutagenic strain yield of 21.3 g/L, 17.2% higher than before the mutagenic; PB) test, screening out three significant factors affecting gamma-PGA yield: glucose, ammonium nitrate and zinc sulfate; 37.88; Ammonium nitrate 0.41, zinc sulfate 0.14, sodium glutamate 40, yeast paste 8, potassium dihydrophosphate 2, magnesium sulfate 0.1, sulfuric acid 0.02, fermentation final yield of 28g/L, 33.17% higher than before optimization. Conclusion: The porous plate method combined with the response surface optimization method can significantly accelerate the screening and optimization speed, and the results are reliable.

Objective: to select a strain with high yield of γ - polyglutamic acid (γ - PGA) and optimize its fermentation medium. Methods: Bacillus sp. X-1 was selected as the starting strain in the early stage of the laboratory, which was screened by the combination of chemical mutagen and ultraviolet combined with the transparent circle method of skimmed milk, and identified by molecular biology; the fermentation medium of the strain was quickly optimized by 24 pore plate combined with response surface method to determine the best fermentation formula. Results: after 16S rDNA sequence analysis, strain X-1 was identified as Bacillus subtilis. A mutant strain n-2 with high yield of γ - PGA was obtained by the combined mutagenesis of three chemical mutagens and UV. After mutagenesis, the yield of mutant reached 21.3g/l, 17.2% higher than that before mutagenesis. By Pb (Plackett Burman, Pb) test, three factors that significantly affect the yield of γ - PGA were screened: glucose, ammonium nitrate and zinc sulfate. The steepest climbing test was used to approach the maximum yield area, and box be was used After 250ml conical flask fermentation, the optimal fermentation medium formula was determined as follows: glucose 37.88; ammonium nitrate 0.41, zinc sulfate 0.14, sodium glutamate 40, yeast extract 8, potassium dihydrogen phosphate 2, magnesium sulfate 0.1, sulfuric acid 0.02, the final fermentation yield was 28g / L, 33.17% higher than before. Conclusion: porous plate method combined with response surface optimization method can significantly accelerate the screening and optimization speed, and the results are reliable.