Study On Laccase Of Pycnoporus Sanguineus Regulating Bioremoval Of Sulfonamides Under Mixed Culture With Alcaligenes Faecalis

Sulfonamides enter the environment as a consequence of animal waste disposal,and they cannot be efficiently eliminated in the environment.Due to the increased occurrence of sulfamethoxazole(SMX)in the aquatic environment,it has become a major public health concern.In the present study,P.sanguineus was cultivated to produce laccase for biodegradation of sulfonamides.P.sanguineus was cultivated in the chemically defined medium to produce laccase,reaching approximately 3.6 U·m L-1 after 5 days of cultivation.Treatment with the laccase-ABTS oxidation system was performed in the extracellular fluid of P.sanguineus growth culture without any purification step.After a 48 h incubation period to produce sufficient amounts of laccase(0.4 – 0.6 U·m L-1)to effectively react with ABTS for degradation,sulfamethoxazole was completely removed within 6 hours.Simultaneous treatment of SMX and sulfadiazine(SDZ)was achieved with removal rates of 82 percent for SMX and 85 % for SDZ.An alternative to the laccase-ABTS oxidation system was the controlled mixture of Alcaligenes faecalis and P.sanguineus,which was more environmental and addresses the environmental concerns.93 % of SMX was eliminated by mixed culture.Laccase production by the coculture effectively inhibited the accumulations of N-hydroxy-SMX and alleviated the cytotoxicity of SMX transformation products.Simultaneous treatment of sulfamethoxazole,sulfadiazine and sulfamethazine by mixed culture was studied in the presence of lignocellulosic waste materials.With initial size of A.faecalis under 0.2-0.4 OD600 nm,the optimal p H at 5,the removal rates of SMX,SDZ and sulfamethazine(SMT)exceeded 98 %,72 % and 83 %.