Degradation of dimethyl isophthalate by Viarovorax paradoxus strain T4 isolated from deep-ocean sediment of the South China Sea

TY - JOUR

T1 - Degradation of dimethyl isophthalate by Viarovorax paradoxus strain T4 isolated from deep-ocean sediment of the South China Sea

AU - Wang, Y. P.

AU - Gu, J. D.

N1 - Funding Information: This research was financially supported by RGC Central Allocation CA00/01.SC01 and 863 Project (No. 2002AA601160) supplement fund by The University of Hong Kong. We thank Li Pan for the determination of the 16S rDNA sequence of the bacterium.

PY - 2006/4

Y1 - 2006/4

N2 - Viarovorax paradoxus T4 strain was isolated from deep-ocean sediment and demonstrated to be able to degrade dimethyl isophthalate (DMI). When DMI was utilized as the sole source of carbon and energy, it was transformed by hydrolysis initially, forming monomethyl isophthalate (MMI) and isophthalate acid (IA) as degradation intermediates. DMI and MMI were completely transformed to MMI and IA in about 100 h, respectively. Degradation of IA was completed in about 55 h. Analysis of total organic carbon in the culture medium confirmed that more than 80% of the substrate carbon was mineralized. Bacterial esterase induced by a range of substrates could be assessed using p-nitrophenyl acetate as the common substrate using crude enzyme preparation. The decreasing trend of Km values derived from the Michaelis-Menten equation was dimethyl phthalate (DMP) > monomethyl phthalate (MMP) > dimethyl terephthalate (DMT) > Liver esterase > DMI > MMI > monomethyl terephthalate (MMT), indicating that higher Km values were obtained by di-esters than mono-ester and the esters induced by terephthalate esters showed the highest activity. This investigation suggests that biochemical pathways for phthalate esters share many common characteristics and the esterases induced by different substrates are highly specific.

AB - Viarovorax paradoxus T4 strain was isolated from deep-ocean sediment and demonstrated to be able to degrade dimethyl isophthalate (DMI). When DMI was utilized as the sole source of carbon and energy, it was transformed by hydrolysis initially, forming monomethyl isophthalate (MMI) and isophthalate acid (IA) as degradation intermediates. DMI and MMI were completely transformed to MMI and IA in about 100 h, respectively. Degradation of IA was completed in about 55 h. Analysis of total organic carbon in the culture medium confirmed that more than 80% of the substrate carbon was mineralized. Bacterial esterase induced by a range of substrates could be assessed using p-nitrophenyl acetate as the common substrate using crude enzyme preparation. The decreasing trend of Km values derived from the Michaelis-Menten equation was dimethyl phthalate (DMP) > monomethyl phthalate (MMP) > dimethyl terephthalate (DMT) > Liver esterase > DMI > MMI > monomethyl terephthalate (MMT), indicating that higher Km values were obtained by di-esters than mono-ester and the esters induced by terephthalate esters showed the highest activity. This investigation suggests that biochemical pathways for phthalate esters share many common characteristics and the esterases induced by different substrates are highly specific.

KW - Biochemical pathway

KW - Dimethyl isophthalate

KW - Esterase

KW - Isophthalate

KW - Monoisophthalate

KW - Plasticiser

UR - http://www.scopus.com/inward/record.url?scp=33645107576&partnerID=8YFLogxK

U2 - 10.1080/10807030500531521

DO - 10.1080/10807030500531521

M3 - 文章

AN - SCOPUS:33645107576

SN - 1080-7039

VL - 12

SP - 236

EP - 247

JO - Human and Ecological Risk Assessment (HERA)

JF - Human and Ecological Risk Assessment (HERA)

IS - 2

ER -