难降解有机物对白腐真菌P450的诱导及P450的作用

实验考察了多环芳烃和氯酚类化合物对黄孢原毛平革菌P450的诱导作用及其P450对生物降解的影响.结果表明,萘、菲、2,4-二氯酚、五氯酚能够诱导该真菌P450,使微粒体P450比浓度达到37~137pmol/mg.在营养限制条件下,菲诱导的P450是营养丰富条件的5.7倍;P450抑制剂的作用使萘、菲、芘、2,4-二氯酚的降解效率下降36%~100%,但是对2,4,6-三氯酚和五氯酚的降解未产生影响.在营养丰富条件下,P450抑制剂的作用使萘、菲、芘、2,4,6-三氯酚的降解效率下降47%~100%,使五氯酚的降解效率增大57%,但对2,4-二氯酚的降解未产生影响.

Induction and function of cytochrome P450 in degradation of refractory organic chemicals by Phanerochaete chrysosporium

The involvement of P450 in degradation of polycyclic aromatic hydrocarbons and chlorophenols by white rot fungus Phanerochaete chrysosporium was investigated. The significant induction of P450s by naphthalene, phenanthrene, 2,4-dichlorophenol and pentachlorophenol were observed. The specific concentrations of microsomal P450s were up to 37~137 pmol/mg in the induced cells. The content of phenanthrene-induced P450 from nutrient-limited culture was 5.7 times higher than that from nutrient-sufficient culture. Piperonyl butoxide (PB), a P450 inhibitor, markedly inhibited the degradation of naphthalene, phenanthrene and pyrene in both nutrient-limited and nutrient-rich culture medium. Moreover, in nutrient-limited culture medium, PB inhibited 2,4-diclorophenol degradation but had no effect on degradation of 2,4,6-triclorophenol and pentachlorophenol. In nutrient-rich culture medium, in contrast, PB inhibited 2,4,6-triclorophenol degradation but did not affect 2,4-diclorophenol degradation. The degradation of pentachlorophenol was even elevated with the presence of PB in nutrient-rich cultures.