Bioremediation of pollutants by xenobiotic ligninolytic fungi

研究了白腐菌降解二恶英和多氯联苯的方法。研究了白腐真菌Phanerochaete sordida YK-624在固定低氮培养基中降解共10种四元至八元的多氯二苯并对二恶英（pcdd）和多氯二苯并呋喃（PCDFs），分别为2-、3-、7-和8位。pcdd和pcdf的降解率分别为0.40（四氯-）-76（六氯-）%和45（四氯-）-70（六氯）%。研究了P.sordida YK-624对2,3,7,8-四氯-和1,2,3,3,4,6,7,8,9 -八氯-和二苯并对二恶英的代谢产物，证实了4,5-二氯-1,2-苯并醌和3,4,5,6-四氯-1,2-苯并醌是二苯并二恶英核的氧化裂解产物。多氯联苯首先被羟基化，然后C-C键被裂解形成苯甲酸衍生物。这些结果表明，白腐菌基本上能够降解pcdd / pcdf和PCBs。综上所述，本文首次报道了微生物对高氯化PCDDs和PCDFs的降解。

Methods of degradation of dioxins and PCBs by white rot fungi were developed. Degradation of a mixture of total 10 kinds of tetra to octa of polychlorodibenzo-p-dioxins (PCDDs) and polychlorodibenzofurans (PCDFs), which were chlorinated 2-, 3-, 7- and 8-positions of the molecules, by white rot fungi Phanerochaete sordida YK-624 was studied in a stationary low nitrogen medium. The degradation rates of PCDDs and PCDFs were ca.40 (tetrachloro-) -76 (hexachloro-) % and 45 (tetrachloro-) -70 (hexachloro) %, respectively. Of PCDDs, metabolites of 2,3,7,8-tetrachloro-, and 1,2,3,4,6,7,8,9-octa-, dibenzo-p-dioxin by P.sordida YK-624 were studied and 4,5-dichloro-1,2-benzoquinone and 3,4,5,6-tetrachloro-1,2-benzoquinone were confirmed as oxidatitive cleavage products of dibenzodioxin nuclus. PCBs were first hydroxylated and then C-C bonds were cleaved to form benzoic acid derivatives. These results suggested that the white rot fungi are substantially able to degrade both PCDDs/PCDFs and PCBs. In conclusion, this is the first report on the degradation of highly chlorinated PCDDs and PCDFs by microorganisms.