Biodegradation Research Of Nitrogen Heterocyclic Compounds In Simulating Soil By White Rot Fungi

Nitrogen heterocyclic compounds are kinds of more toxic, wide polluted refractory organics which bring more serious pollution of nitrogen in the soil environment, the processing of heterocyclic compounds for research to contaminated soil remediation have important significance. Due to non-specific ability, broad spectrum property and other characteristics of white-rot fungi, white-rot fungi are widely used in the process of environmental management, and have positive significant in the aspects of bioremediation for polluted soil. In this paper, white rot fungi were used to degrade nitrogen heterocyclic compounds in simulating soil.This paper studied biological characteristics of white rot fungi Pleurotus ostreatus, and discussed the changes of laccase activity, protein content and glucose content of white rot fungi in synthetic medium and natural medium.In the degradation systems of solo-substrate of nitrogenous heterocyclic compounds in simulating soil, biodegradations of quinoline and indole by white rot fungi were discussed, and results showed that the removal of quinoline reached 88.7% at most and indole reached 89.9%. The addition of wood dust could accelerate the removal of quinoline and indole in biodegradation of polluted soil. The conditions of various water ratio and pH value were studied in the biodegradation processes of quinoline and indole, and the best water ratio and soil pH were obtained in simulating soil. In quinoline-contaminated soil, the removal was higher when soil moisture was rising, and the best pH value of soil was 7~8. In indole-contaminated soil, the removal was higher when soil moisture was reduced, and the best pH value of soil was 7.5~8.5. In the study of inoculation size of white rot fungi, inoculation influence on removal of quinoline and indole was determined, which degradation was improved when inoculation increased.In the degradation systems of solo-substrate simulating soil, the laccase which secreted by white rot fungi need induction period to adapt the substrates and environmental conditions, and white rot fungi cultured in the natural medium has better tolerace in simulating soil. Interaction in the degradation systems of co-substrate of nitrogenous heterocyclic compound by white rot fungi was discussed. Quinoline had inhibiting effect on degradation of indole.