Phylogenetical approach to isolation of white-rot fungi capable of degrading polychlorinated dibenzo-p-dioxin
Phylogenetical approach to isolation of white-rot fungi capable of degrading polychlorinated dibenzo-p-dioxin
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DOI：
10.1007/s00253-005-0052-4
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发表时间：
2005-12-01
影响因子：
5
通讯作者：
Kondo, R
中科院分区：
文献类型：
--
作者：
Kamei, I;Suhara, H;Kondo, R
对新分离到的2,7-二氯二苯并-对二恶英（2,7- dicdd）降解白腐菌BMC3014、BMC9152和BMC9160进行了pcdd降解实验和系统发育分析。当这些真菌与三或四tradds孵育时，底物被有效降解，并检测到羟基化代谢物。另一方面，1,3,6,8-四氯二苯并-对二恶英没有减少，也没有检测到代谢物。对含有rRNA基因序列的内部转录间隔段（ITS-rDNA）的系统发育分析表明，这些菌株属于Phlebia属，与我们在前期研究中分离到的2,7- dicdd降解真菌Phlebia lindtneri菌株MZ-227和MG-60亲缘关系密切。基于这一系统发育关系，利用其他Phlebia属对2,7- dicdd和1,3,6,8- tetracdd进行了降解实验。在14天的孵育过程中，白蜡球和短孢球对2,7- dicdd的降解率分别为40%和80%。结果表明，短叶苋可降解1,3,6,8- tetracdd，并在处理培养中转化为单羟基- tetracdd、单甲氧基- tetracdd、二甲氧基- tetracdd、二甲氧基- tricdd和3,5-二氯儿茶酚。本文首次通过代谢物鉴定，明确证明白腐菌短叶白腐菌可以降解顽固性二恶英1,3,6,8- tetracdd。
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 R 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.