Isolation, identification, and culture optimization of a novel glycinonitrile-hydrolyzing fungus-Fusarium oxysporum H3.

Microbial transformation of glycinonitrile into glycine by nitrile hydrolase is of considerable interest to green chemistry. A novel fungus with high nitrile hydrolase was newly isolated from soil samples and identified as Fusarium oxysporum H3 through 18S ribosomal DNA, 28S ribosomal DNA, and the internal transcribed spacer sequence analysis, together with morphology characteristics. After primary optimization of culture conditions including pH, temperature, carbon/nitrogen sources, inducers, and metal ions, the enzyme activity was greatly increased from 326 to 4,313 U/L. The preferred carbon/nitrogen sources, inducer, and metal ions were glucose and yeast extract, caprolactam, and Cu(2+), Mn(2+), and Fe(2+), respectively. The maximum enzyme formation was obtained when F. oxysporum H3 was cultivated at 30 °C for 54 h with the initial pH of 7.2. There is scanty report about the optimization of nitrile hydrolase production from nitrile-converting fungus.