Biodegradation kinetics of nitriles with easily degradable substrate by Klebsiella oxytoca GS-4-08

Nitrile compounds are common toxic and refractory organic wastes in industrial wastewater, and can be efficiently treated through biodegradation. The strain Klebsiella oxytoca GS-4-08 could utilize nitriles as the sole nitrogen source for growth, and the nitrile biodegradation kinetics showed good linear correlation with cell growth and glucose consumption. Degradation kinetics showed that the reaction order was dependent on initial cell concentration, and the degradation rates were increased when more easily degradable substrate was available. Higher acetonitrile (ACN) concentration inhibited not only the cell growth but also the ACN degradation. Haldane model constants indicated a high tolerance ability of K. oxytoca to acetonitrile. The formation of acetate during High Performance Liquid Chromatography (HPLC) wastewater treatment showed that the strain has a great potential for treating real nitriles-containing wastewater, and for organic acid production.