Research Of The Yield Of γ-PGA Extracted From Bacillus Natto Which Treated By Corona Electric Field-Ion Beam Composite Mutagenesis

In this experiment, we use bacillus natto as mutagenesis bacterium. By the mutagenesis method of composite electric field-ion beam, we plan to breeding a high-yield y-PGA mutational bacterial strain.At first, start the experiment with bacillus natto of high-yield y-PGA. Treat the bacteria suspension with different strengths of needle-plate corona electric field. And then using the selected strength of corona electric field mutates bacterial strain. Finally screen the high-yield mutational bacterial strain through fermentation. The result shows that nattoOl strain emerges plenty of ruga after24h and has obvious wire drawing. Yield of y-PGA that extracted from the fermentation supernate via freeze-drying method has increased129.78%.Next, using different N+doses of ion beams mutate the high-yield mutational bacterial strain we’ve got. That is to say, choose the appropriate dose do compound mutation to the high-yield mutational bacterial strain. The best does is3.9×1015ions.cm-2. In this does, we got a high-yield mutational bacterial strain whose yield of y-PGA increased52.62%.Subculture the mutational bacterial strain, mutated with composite electric field-ion beam,5generations. The yield of y-PGA is4times of original bacterial.