Abstract: Sulfonamides are a class of antimicrobial agents that have been detected in China at high-frequency. Biological method has the advantages of no secondary pollution and green environmental protection,but the researches on biodegradation of sulfonamides is still scarce. This experiment was to investigate degradation of sulfamethazine（SM2）by co-culturing Trametes versicolor and Phanerochaete chrysosporium. Antibiotic concentration and enzyme activity were determined using high performance liquid chromatography（HPLC）and UV spectrophotometer. A deadlock between the two mycelia was observed on plate confrontation method of an agar medium. The laccase activity at the interaction zone was higher than that at the other regions in the incubation of the two white-rot fungi on an agar plate. The crude enzyme preparation with high laccase concentration was obtained at the co-culturing time of 4 days in liquid medium. At 48 h after incubation,the degradation percentage of SM2 by crude enzyme solution from co-culturing was 25.4%,which was higher than that by crude enzyme preparations from Trametes versicolor（9.6%）. When natural mediators and artificial mediator 2,2’-azinobis（3-ethylbenzthiazoline-6-sulfonic acid ammonium salt）（ABTS）were added to the reaction mixture,the degradation percentages of SM2 by the crude enzyme from mixed culture significantly increased to 49% and 93.1%,respectively. The results showed that the interspecific interactions involving P. chrysosporium and T. versicolor enhanced the SM2 oxidation through increasing laccase activity and producing potential mediators. Therefore,the co-culturing of different white-rot fungi has potential for application in antibiotic-contaminated soils and wastes.

Key words: white-rot fungi, co-culture, laccase activity, sulfamethazine, degradation