Characteristics Of Enzyme For Decolorization Of Bromamine Acid

Bromamine acid(BAA)is an important active dyestuff intermediate.It has a specific configuration which two benzene rings are strongly affected by two carbonyl groups beside them.Because of this and its good water solubility.,BAA is always hard to be degraded by microorganism.So it can last long in the environment.Studies on the degradating enzyme and the degradation pathway of bromamine acid can lay a foundation to that of the anthraquinone.The purpose of this dissertation is to investigate the characteristics of the crude enzyme degrading bromamine acid.The degradation products of BAA by the enzyme were investigated and the possible metabolic pathway of BAA degradation was presumed.The characteristics of the whole cells for biodegradation of BAA were investigated.The components of the mineral medium were K₂HPO₄1.5g/L,KH₂PO₄1.5g/L,acetic sodium1g/L. The whole cells were suspended in 0.01mol/L phosphate buffer at a concentration of 10mg/ml (wet wt).The optimal conditions for degradation process were as follows:pH,7.0,30℃, 150r/min.The degradation products were detected by UV-vis and HPLC-MS.A new product o-Phthalic Acid was discovered as the midde product.Also the final product 2-amino-3-hydroxyl-5-bromophenyl-sulfonic acid and 2-amino-4-hydroxyl-5-bromophenyl-sulfonic acid affm-ned earlier were also detected.We can come to a conclusion that BAA directly cleave into these three products.The crude enzyme was obtained through the treatment of ultrasonic disruption and centrifugation.The enzyme was confirmed as induced enzyme but not constitutive enzyme. The necessary coenzyme was NADH.The optimal conditions for degradation process were as follows:pH=7.5,50℃.The kinetic properties on degradation of BAA were studied.The Michaelis constant Km was found to be 3×10^-4mol/L,and the maximum degradation rate of BAA under the catalysis of the crude enzyme reach 6.993×10^-9mol/(min·mg protein).The metabolic products of BAA by crude enzyme was investigated by HPLC-MS.The final products were identified to be the same as those acquired from the whole cells'degradation.