Mutagenesis and Characterization of Hyaluronidase Production by a New Isolate of Citrobacter portucalensis

Hyaluronidase, a glycosidase, has the capacity to degrade hyaluronic acid. It is employed within both the medical and cosmetic domains and represents an efficacious methodology for the preparation of hyaluronic acid oligosaccharides. The increase in the activity of hyaluronidase has been demonstrated to be an effective method of promoting the production of low molecular weight hyaluronic acid. In the present study, we identified the active hyaluronan-degrading strain Citrobacter portucalensis HA23 from a sodium hyaluronate solution kept at natural room temperature, with independent intellectual property rights. To enhance the strain’s enzyme-producing capacity, we employed atmospheric and room temperature plasma (ARTP) technology to select and breed the mutant HA2301 with augmented enzyme-producing capabilities. The enzyme activity of the mutant strain HA2301 was observed to have increased by 58.82% in comparison to that of HA23. It was established that pH 5.5, 37 °C, and 250 rpm represented the optimal culture conditions, with the enzyme activity of the strain reaching 25808 U mL^–1 in a medium comprising a carbon source of yeast flour and a nitrogen source of peanut cake flour. The reaction solution of the enzyme with sodium hyaluronate was characterized, with the main products identified as HA2 and HA4. The present text provides a reference for its industrial application.