DEGRADATION OF BENZOATE VIA BENZOYL-COENZYME-A AND GENTISATE BY BACILLUS-STEAROTHERMOPHILUS PK-1, AND PURIFICATION OF GENTISATE 1,2-DIOXYGENASE

Citation
P. Kiemer et al., DEGRADATION OF BENZOATE VIA BENZOYL-COENZYME-A AND GENTISATE BY BACILLUS-STEAROTHERMOPHILUS PK-1, AND PURIFICATION OF GENTISATE 1,2-DIOXYGENASE, Biology and fertility of soils, 23(3), 1996, pp. 307-313
Citations number
43
Categorie Soggetti
Agriculture Soil Science
ISSN journal
01782762
Volume
23
Issue
3
Year of publication
1996
Pages
307 - 313
Database
ISI
SICI code
0178-2762(1996)23:3<307:DOBVBA>2.0.ZU;2-O
Abstract
The thermophilic Bacillus stearothermophilus PK1 utilized benzoate, 3- hydroxybenzoate, and gentisate as sole source of carbon and energy. 2- and 4-Hydroxybenzoate, 2,3- and 3,4-dihydroxybenzoate, and catechol d id not support growth. Degradation of benzoate proceeded via benzoyl-c oenzyme A (benzoyl-CoA) and gentisate. The inducible benzoyl-CoA ligas e converted benzoate but not 3-hydroxybenzoate to its coenzyme A thioe ster. Gentisate 1,2-dioxygenase from B. stearothermophilus PK1 was pur ified to homogeneity. The enzyme is presumed to be a homohexamer with a subunit molecular mass of 40 kDa. It showed maximal activity at 65-7 0 degrees C. After incubation for 80 min at 65 degrees C, 50% of the o riginal activity was lost. Gentisate 1,2-dioxygenase activity from str ain PK1 was strictly dependent on exogenously added Fe2+, and it was i nhibited by, metal-chelating agents, indicating an essential role of F e2+ in catalysis.