Progress in study on microbial enzymes for the metabolism of environmental refractory organic compounds / 生物工程学报

With the rapid development of socialization and industrialization, more and more pollutes were produced and discharged into natural environment. It is harmful to human health and life. These pollutes included refractory degradation organic compounds like PAHs, RDX, HMX, CL-20, PCBs and alkanes and their relative substances. Various compounds exist in nature with long life span. They are the most hazardous than other organics. The impact of pollutes can be treated by microorganisms. Results showed that it is an effective way for bioremediation of these pollutes with microbial metabolism or cometabolism. A few key enzymes, mainly oxidative and reductive enzymes, connected with the first step of initial degradation. Normally, enzymes grouped with other active fraction on the cell membrane are composed of one oxidative and reductive system for substrates oxidation. The metabolic intermediates can be used with TCA by microorganisms. The pathways of metabolism and the key enzymes were summarized. The further research topics should be focused on microorganism screen and its relative enzyme, pathway and mechanism of metabolism or cometabolism for such compounds degradation, and the result was hoped for the environmental protection.

Production of ligninase by co-fermentation of Coprinus comatus and Trichoderma reesei / 生物工程学报

In order to enhance the utilization efficiency, reduce the environmental pollution of traditional chemical treatment and the agriculture waste incineration; we studied the ligninase production by Coprinus comatus, Aspergillus niger and Trichoderma reesei through the plate screening. The results showed that C. comatus mixed culture with T. reesei have a good compatibility and higher yields of Laccase. On the basis of this pre-experiment, we studied the optimal conditions of mixed culture for enzyme production. Under the optimal conditions: the inoculation proportion of C. comatus and T. reesei (5:2), the interval of time (12 h), the temperature 260C, the shake rotation speed 150 r/min, fermented for 3 days, the Laccase activity reached 3267.1 U/mL, increased by 106% contrasted with single culture of C. commatus.