Comparison of initial hydrolysis of the three dimethyl phthalate esters (DMPEs) by a basidiomycetous yeast, Trichosporon DMI-5-1, from coastal sediment
Comparison of initial hydrolysis of the three dimethyl phthalate esters (DMPEs) by a basidiomycetous yeast, Trichosporon DMI-5-1, from coastal sediment
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DOI：
10.1007/s11356-011-0525-1
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发表时间：
2011-05
影响因子：
5.8
通讯作者：
Zhuhua Luo;Yi-Rui Wu;K. Pang;J. Gu;L. Vrijmoed
中科院分区：
文献类型：
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作者：
Zhuhua Luo;Yi-Rui Wu;K. Pang;J. Gu;L. Vrijmoed
目的邻苯二甲酸二甲酯（DMPEs）是环境中常见的增塑剂，对人体健康具有潜在的危害。已经在有限程度上研究了真菌系统对DMPEs的降解，特别是酵母。本研究从海洋沉积物中筛选到一株能降解DMPEs的担子菌酵母Trichosporonsp-5-1，并对其降解途径进行了初步研究。根据显微形态和18 S rDNA序列分析，初步鉴定了拟南芥中的一个新种-拟南芥-5-1。比较研究了该酵母菌对DMPEs的3种异构体邻苯二甲酸二甲酯（DMPEs）、对苯二甲酸二甲酯（DMPEs）和对苯二甲酸二甲酯（DMPEs）的生物降解性能。DMPEs不能完全矿化，但可分别转化为邻苯二甲酸单甲酯或邻苯二甲酸。丝孢酵母对DMPE三种异构体的生化降解途径。5.1显然不同。酵母进行一步酯水解的邻苯二甲酸酯和邻苯二甲酸酯的各自的单酯（单甲基邻苯二甲酸酯和单甲基邻苯二甲酸酯，分别）和没有进一步代谢这两种单酯。同时，DMT转化的酵母单甲基对苯二甲酸酯，随后对苯二甲酸逐步水解的两个酯bonds.ConclusionsThis研究表明，不同的催化过程参与转化的DMPEs的担子菌酵母Trichosporonsp。酯酶是DMPEs的两个酯键的水解酶，具有高度的底物特异性。
PurposeDimethyl phthalate esters (DMPEs) are a group of plasticizers commonly detected in the environment with potential adverse human health impact. The degradation of DMPEs by fungal systems has been studied to a limited extent, particularly by yeasts. In this study, a basidiomycetous yeastTrichosporonDMI-5-1 capable of degrading DMPEs was obtained and the degradation pathways were investigated.ResultsA DMPE-degrading yeast was isolated from costal sediment by enrichment culture technique and was identified asTrichosporonsp. DMI-5-1 based on microscopic morphology and 18S rDNA sequence. Comparative investigations on biodegradation of three isomers of DMPEs, namely dimethyl phthalate (DMP), dimethyl isophthalate (DMI), and dimethyl terephthalate (DMT), were carried out with this yeast strain.Trichosporonsp. DMI-5-1 could not mineralize DMPEs completely but transform them to respective monomethyl phthalate or phthalic acid. Biochemical degradation pathways for the three DMPE isomers byTrichosporonsp. DMI-5-1 were apparently different. The yeast carried out one-step ester hydrolysis of DMP and DMI to respective monoesters (monomethyl phthalate and monomethyl isophthalate, respectively) and no further metabolism of these two monoesters. Meanwhile, DMT was transformed by the yeast to monomethyl terephthalate and subsequently to terephthalic acid by stepwise hydrolysis of the two ester bonds.ConclusionsThis study shows that different catalytic processes are involved in the transformation of DMPEs by the basidiomycetous yeastTrichosporonsp. DMI-5-1 and suggests that its esterases, responsible for the initial hydrolyzing the two ester bonds of DMPEs, are highly substrate specific.