TY - JOUR
T1 - Comparison of initial hydrolysis of the three dimethyl phthalate esters (DMPEs) by a basidiomycetous yeast, Trichosporon DMI-5-1, from coastal sediment
AU - Luo, Zhu Hua
AU - Wu, Yi Rui
AU - Pang, Ka Lai
AU - Gu, Ji Dong
AU - Vrijmoed, Lilian L.P.
N1 - Funding Information:
Acknowledgments The work described in this paper was substantially supported by grants from City University of Hong Kong (Project Nos. 7002220 and 9610037), the Research Grants Council of the Hong Kong Special Administrative Region, China (Project No. CA04/ 05. SC01), and National Natural Science Foundation of China (Project No. 41006099), which are gratefully acknowledged. The authors would also like to thank Ms. Jessie Lai of The University of Hong Kong and Miss Alice Chan of City University of Hong Kong for technical support in HPLC analysis.
PY - 2011/11
Y1 - 2011/11
N2 - Purpose: Dimethyl 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 yeast Trichosporon DMI-5-1 capable of degrading DMPEs was obtained and the degradation pathways were investigated. Results: A DMPE-degrading yeast was isolated from costal sediment by enrichment culture technique and was identified as Trichosporon sp. 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. Trichosporon sp. 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 by Trichosporon sp. 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. Conclusions: This study shows that different catalytic processes are involved in the transformation of DMPEs by the basidiomycetous yeast Trichosporon sp. DMI-5-1 and suggests that its esterases, responsible for the initial hydrolyzing the two ester bonds of DMPEs, are highly substrate specific.
AB - Purpose: Dimethyl 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 yeast Trichosporon DMI-5-1 capable of degrading DMPEs was obtained and the degradation pathways were investigated. Results: A DMPE-degrading yeast was isolated from costal sediment by enrichment culture technique and was identified as Trichosporon sp. 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. Trichosporon sp. 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 by Trichosporon sp. 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. Conclusions: This study shows that different catalytic processes are involved in the transformation of DMPEs by the basidiomycetous yeast Trichosporon sp. DMI-5-1 and suggests that its esterases, responsible for the initial hydrolyzing the two ester bonds of DMPEs, are highly substrate specific.
KW - Basidiomycetous yeast
KW - Biodegradation
KW - Dimethyl phthalate esters
KW - Plasticizers
KW - Trichosporon sp.
UR - http://www.scopus.com/inward/record.url?scp=80053983325&partnerID=8YFLogxK
U2 - 10.1007/s11356-011-0525-1
DO - 10.1007/s11356-011-0525-1
M3 - 文章
C2 - 21626443
AN - SCOPUS:80053983325
SN - 0944-1344
VL - 18
SP - 1653
EP - 1660
JO - Environmental Science and Pollution Research
JF - Environmental Science and Pollution Research
IS - 9
ER -
