Impact Of Corona Electic Field On γ-PGA Extracted From Bacillus Natto

Corona electric field through the needle plate to Bacillus natto bacteria suspension. Bacillus natto occur not directed mutagenesis. Pick out strains containing the desired traits.the initial strain is Bacillus natto stored in the laboratory at -70 ℃. The activated of Bacillus natto training 15h. Preparation of the bacterial suspension. Design of several different sets of electric field intensity and different time experiment. These types of electric field applied separately to natto bacillus bacterial suspension. To make it happen not directed mutagenesis. The mutant bacteria and initial bacteria was inoculated to solid medium. Observe the growth status and colony shape. Find many different colony morphology mutant strain. Strain through liquid fermentation synthesis γ-PGA and weigh γ- PAG quality. Then selected Bacillus natto that γ-PGA production increased. Selection results:Mutant strains produce γ- PGA yield 21.2g/L. Initial bacterial produce γ-PGA yield 2.6g/L. Producing strain of γ- PGA yield becomes the initial strain 8 times Producing strain through three generations subculture, γ-PGA output unchanged. Description this trait is heritable variation.By strains were cultured on solid media to observe the colony status and colony morphology. Producing strain colonies thick, surface has more wrinkles, irregular jagged edges. There is a bubble, the bubble area accounts for about 4/5 of the colony. The colony viscosity, inoculation needles can be formed when picked drawing and drawing longer the greater the likely yield. A single colony selection of suitable according to these conditions. Producing strain broth viscosity not easy to centrifugation and it has darker color. Before separating the cells need to add an appropriate amount of hydrochloric acid to reduce pH. As the pH is reduced to reduce broth viscosity, it is easy separation of the cells and subsequent extraction operation.