Production of a thermostable uricase by a novel Bacillus thermocatenulatus strain

A novel uricase-producing bacterium was identified based on its 16S rRNA sequence as Bacillus thermocatenulatus. The kinetic constants for this uricase, determined with uric acid as the substrate, were a Vmax of 0.99 U/ml of enzyme and a Km of 0.25 mM. After heat treatment at 75 °C for 45 min, the uricase retained about 100% of its initial activity. The uric acid showed to be an inducer for uricase production. The effects of different factors on the enzyme production were studied. Pretreated cane molasses and corn steep liquor were the most promising carbon and nitrogen sources, respectively. When the strain was cultured at 30 °C at pH 7.0 for 30–36 h, the uricase activity peaked at 1.25 U/ml.