Degradability of dimethyl terephthalate by Variovorax paradoxus T4 and Sphingomonas yanoikuyae DOS01 isolated from deep-ocean sediments

TY - JOUR

T1 - Degradability of dimethyl terephthalate by Variovorax paradoxus T4 and Sphingomonas yanoikuyae DOS01 isolated from deep-ocean sediments

AU - Wang, Yu Ping

AU - Gu, Ji Dong

PY - 2006/8

Y1 - 2006/8

N2 - Two strains of bacteria were isolated from deep-ocean sediments of the South China Sea using enrichment culturing technique and they were identified as Sphingomonas yanoikuyae DOS01 (AY878409) and Variovorax paradoxus T4 (AY878410) based on 16S rRNA gene sequences. S. yanoikuyae DOS01 was only capable of transforming dimethyl terephthalate (DMTP) to monomethyl terephthalate (MMTP) without further degradation while V. paradoxus T4 exhibited ability in mineralizing DMTP as the sole source of carbon and energy. The biochemical pathway of DMTP degradation was through MMTP and terephthalic acid (TA) as major detectable degradation intermediates in the culture media by both microorganisms. V. paradoxus T4 utilized DMTP and MMTP via hydrolysis of diester and monoester in the initial steps in degradation as confirmed by total organic carbon analysis of the culture medium and esterase activity assay of the lysed cells and fraction. The specific hydrolysis activity of esterase induced by DMTP or MMTP showed that greater hydrolysis of p-nitrophenyl acetate by esterase induced by DMTP-grown cells than that induced by MMTP. Results of this research suggest that the cleavage of the two identical carboxylic ester groups of phthalate diester are carried out by highly specific esterases of the same bacteria in the environment.

AB - Two strains of bacteria were isolated from deep-ocean sediments of the South China Sea using enrichment culturing technique and they were identified as Sphingomonas yanoikuyae DOS01 (AY878409) and Variovorax paradoxus T4 (AY878410) based on 16S rRNA gene sequences. S. yanoikuyae DOS01 was only capable of transforming dimethyl terephthalate (DMTP) to monomethyl terephthalate (MMTP) without further degradation while V. paradoxus T4 exhibited ability in mineralizing DMTP as the sole source of carbon and energy. The biochemical pathway of DMTP degradation was through MMTP and terephthalic acid (TA) as major detectable degradation intermediates in the culture media by both microorganisms. V. paradoxus T4 utilized DMTP and MMTP via hydrolysis of diester and monoester in the initial steps in degradation as confirmed by total organic carbon analysis of the culture medium and esterase activity assay of the lysed cells and fraction. The specific hydrolysis activity of esterase induced by DMTP or MMTP showed that greater hydrolysis of p-nitrophenyl acetate by esterase induced by DMTP-grown cells than that induced by MMTP. Results of this research suggest that the cleavage of the two identical carboxylic ester groups of phthalate diester are carried out by highly specific esterases of the same bacteria in the environment.

KW - Deep-ocean

KW - Dimethyl terephthalate (DMTP)

KW - Esterase activity

KW - Hydrolysis

KW - Plastisizer

KW - South China Sea

UR - http://www.scopus.com/inward/record.url?scp=33748961325&partnerID=8YFLogxK

U2 - 10.1007/s10646-006-0093-1

DO - 10.1007/s10646-006-0093-1

M3 - 文章

C2 - 16955363

AN - SCOPUS:33748961325

SN - 0963-9292

VL - 15

SP - 549

EP - 557

JO - Ecotoxicology

JF - Ecotoxicology

IS - 6

ER -