CONVERSION OF CHLOROBIPHENYLS INTO PHENYLHEXADIENOATES AND BENZOATES BY THE ENZYMES OF THE UPPER PATHWAY FOR POLYCHLOROBIPHENYL DEGRADATION ENCODED BY THE BPH LOCUS OF PSEUDOMONAS SP STRAIN LB400

被引:109
作者
SEEGER, M
TIMMIS, KN
HOFER, B
机构
[1] GESELL BIOTECHNOL FORSCH MBH,NATL RES CTR BIOTECHNOL,DEPT MICROBIOL,D-38124 BRAUNSCHWEIG,GERMANY
[2] UNIV CHILE,FAC MED,DEPT BIOQUIM,SANTIAGO 7,CHILE
关键词
D O I
10.1128/AEM.61.7.2654-2658.1995
中图分类号
Q81 [生物工程学(生物技术)]; Q93 [微生物学];
学科分类号
071005 ; 0836 ; 090102 ; 100705 ;
摘要
Metabolism of 21 chlorobiphenyls by the enzymes of the upper biphenyl catabolic pathway encoded by the bph locus of Pseudomonas sp. strain LB400 was investigated by using recombinant strains harboring gene cassettes containing bphABC or bphABCD. The enzymes of the upper pathway were generally able to metabolize mono- and dichlorinated biphenyls but only partially transform most trichlorinated congeners investigated: 14 of 15 mono- and dichlorinated and 2 of 6 trichlorinated congeners were converted into benzoates. All mono- and at least 8 of 12 dichlorinated congeners were attacked by the bphA-encoded biphenyl dioxygenase virtually exclusively at ortho and meta carbons. This enzyme exhibited a high degree of selectivity for the aromatic ring to be attacked, with the order of ring preference being non- > ortho- > meta- > para-substituted for mono- and dichlorinated congeners. The influence of the chlorine substitution pattern of the metabolized ring on benzoate formation resembled its influence on the reactivity of initial dioxygenation, suggesting that the rate of benzoate formation may frequently be determined by the rate of initial attack. The absorption spectra of phenylhexadienoates formed correlated with the presence or absence of a chlorine substituent at an ortho position.
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页码:2654 / 2658
页数:5
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