Enhancement of Gongronella sp. JG Chitosanase Production by Ion Beam Implantation

Gongronella sp. JG was a fungal strain which expressed extracellular chitosanase of about 800 U/L during its growth in production medium. To improve its enzyme production, low energy N+ implantation was employed to mutate spores of JG. The implantation condition was optimized and the parameters of 15 keV and 60 × 2.6 × 1013 ions/cm2 were selected for further breeding experiments. A mutant designated as SG was obtained. It showed increased chitosanase production (1800 U/L) and shortened cultivation period (from 72 h to 60 h). Five-generation cultivation of SG indicated that its chitosanase production was stable at about 1800 U/L.