Phylogenetical approach to isolation of white-rot fungi capable of degrading polychlorinated dibenzo-p-dioxin

Abstract

A degradation experiment on PCDDs and phylogenetical analyses were carried out on newly isolated 2,7-dichlorodibenzo-p-dioxin (2,7-diCDD)-degrading white-rot fungi, strains BMC3014, BMC9152, and BMC9160. When these fungi were incubated with tri- or tetraCDDs, the substrates were degraded efficiently, and hydroxylated metabolites were detected. On the other hand, 1,3,6,8-tetrachlorodibenzo-p-dioxin was not decreased, and no metabolites were detected. Phylogenetic analysis of internal transcribed spacers (ITSs) containing rRNA gene sequence (ITS-rDNA) clarified that these strains belonged to the genus Phlebia and were closely related to the fungi Phlebia lindtneri, strains MZ-227 and MG-60, which had both been isolated as 2,7-diCDD-degrading fungi in our previous study. Based on this phylogenetical relationship, other Phlebia genera species were used for a degradation experiment on 2,7-diCDD and 1,3,6,8-tetraCDD. Phlebia acerina and Phlebia brevispora degraded 2,7-diCDD about 40 and 80%, respectively, over 14 days of incubation. It became clear that P. brevispora can degrade 1,3,6,8-tetraCDD and transform it to monohydroxy-tetraCDD, monomethoxy-tetraCDD, dimethoxy-tetraCDD, dimethoxy-triCDD, and 3,5-dichlorocatechol in the treatment cultures. In this paper, we could clearly prove for the first time by identifying the metabolites that white-rot fungus P. brevispora could degrade the recalcitrant dioxin, 1,3,6,8-tetraCDD.

Saline-Dependent Regulation of Manganese Peroxidase Genes in the Hypersaline-Tolerant White Rot Fungus Phlebia sp. Strain MG-60

“…All mnp genes were closely related to the mnp genes described previously for P. radiata strain 79 (ATCC 64658) (8). Recently, phylogenetic analysis based on the internal transcribed spacer (ITS) region (containing 5.8S ribosomal DNA, ITS1, and ITS2) was carried out (11 MGmnp2 and MGmnp3 were classified as being typical MnP group I representatives (Fig. 3) (19).…”

Removal of estrogenic activity of iso-butylparaben and n-butylparaben by laccase in the presence of 1-hydroxybenzotriazole

“…There is currently great interest in these fungi and their ligninolytic enzymes due to their potential for degrading and detoxifying recalcitrant environmental pollutants, such as polychlorinated dioxins (Kamei et al 2005), chlorophenols (Ehlers and Rose 2005), polycyclic aromatic hydrocarbons (Cambria et al 2008), and dyes (Asgher et al 2008). Furthermore, we recently demonstrated that ligninolytic enzymes such as manganese peroxidase (MnP) and laccase, which are produced extracellularly by white rot fungi, are effective in removing the estrogenic activities of nonylphenol (NP), bisphenol A (BPA), 4-tert-octylphenol, 17b-estradiol (E 2 ), ethinylestradiol, estrone, and genistein (Tsutsumi et al 2001;Suzuki et al 2003;Tamagawa et al 2005Tamagawa et al , 2006Tamagawa et al , 2007, and in degrading methoxychlor ) and the antifouling compound Irgarol 1051 (Ogawa et al 2004).…”

Pollutants Biodegradation by Fungi

“…Removal of dioxins by biological degradation is considered a feasible method as an alternative to other expensive physic-chemistry approaches [80]. Different dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were studied for degradation by fungi such as Phlebia radiata I-5-6 [81,82,83], P. acerina, P. lindtneri and P. brevispora which can hydroxylate and methoxylate PCDDs [84], and Phanerochaete chrysosporium DSM 6909, P. chrysosporium DSM 1556, Irpex sp. W3, Trametes sp.…”