Research On Characteristics Of The Strongest Degradational Strain For DTP And PET Fiber

Poly(ethylene terephthalate) (PET) has been used widely in the world. In order to disposal PET waster or modify the surface of PET fiber, biodegradation of PET fiber has been studied. Because of its hydrophobic nature and its compact structure PET can not be degraded by microorganisms in environment, so we have to screen and isolate PET degrading microorganisms via experiment.In this paper we use DTP as simulacrum to find stronger PET degradation microorganisms. In addition, DTP itself is an environmental hormone.Five strains have been obtained, and the strongest DTP degradational strain has been isolated which was named F4. The characteristics of F4 has been studied. M5 is the best favorite medium to F4, and the higher concentration of DTP in medium, the faster F4 grow. To some extent TA is an inhibitor in the growth of F4. The optimum temperature of the growth of F4 is 30掳C and the optimum pH is 7.5.The influence factor of DTP degradation by F4 has been investigated. The optimum temperature of degradation is 30 C and the optimum pH is 7.5.The effect of degradation in shaking is bigger than motionless and the effect increase when inoculation rise. The degradation kinetic of DTPaccords with Monod equation.The crude enzyme extracted from F4 has been researched. The intracellular enzyme has more effect than extra cellular enzyme. The optimum temperature and pH of the crude enzyme activity to DTP were 30掳C and 7~8 respectively.The Michaelis-Menten's constant (Km) of DTP enzymic degradation was 3.8 m mol/L.The control experiments have been done with Sigma esterase. The optimum temperature and pH of the crude enzyme activity to DTP were 30掳C and 7~8.The Michaelis-Menten's constant (Km) of DTP enzymic degradation was 47 m mol/L.In this paper Sigma esterase, F4 and its intracellular enzyme have been utilized in the degradation of PET fiber .The result showed that F4 and Sigma esterase have some effect to PET fiber, but this effect is very weak. There is no effect using intracellular enzyme and extra cellular enzyme to degrade PET fiber separately, but the mixture of intracellular enzyme and extra cellular enzyme has some effect.The experiment in this paper established a good foundation for the further research.