Mutation Breeding and Enzymatic Properties of Cold-adapted Chitinolytic Strain Photobacterium sp. from Marine

To study the physicochemical properties of the strain Photobacterium sp. LG-1 and improve its enzyme production activity, BIOLOG was used to carry out physiological and biochemical experiments. Parallel breeding through ultraviolet mutagenesis, chemical mutagenesis and compound mutagenesis. Research on its enzymatic properties and antibacterial properties. The enzyme activity of this strain reached 2.690 U/mL after compound mutagenesis, and the increasing rate of enzyme activity was 139.78%. The optimum temperature was 35 °C, and the chitinase still showed catalytic activity at 0 °C. The optimum pH was 8.0, and it had stability in an alkaline environment. Ca²⁺, K⁺, Mg²⁺, Cu²⁺ and Na⁺ could promote chitinase activity. LG-1 had inhibitory activity against Rhizopus, Aspergillus niger, Mucor and rot of Corn .