Study on conditions and preliminary mechanism of TNT biodegradation by the strain S (Klebsiellasp.)

Conditions and preliminary mechanism of TNT biodegradation by the strain S were investigated. The results show that glucose addition greatly enhances the biodegradation of TNT by strain S, and the removal efficiency of TNT reaches 100% after 16h culture; while the removal efficiency of TNT is only 12% without glucose addition, leading to S growth slightly; KNO₃ addition also promotes TNT biodegradation, 100% TNT removal is attained, more than the 80% removal without KNO₃ addition; the increase in TNT concentration has no evident adverse effect on its degradation, the strain S can completely biodegrade TNT even at 200mg/L. The biodegradation of TNT involves that TNT is transformed into condensation product A and then A is degraded through ring cleavage. The existence of nitroreductase, toluene dioxygenase, catchpoll dioxygenase in the S biological catalyst system supplies enzyme basis for TNT degradation.