Müller J A, Galushko A S, Kappler A, Schink B
Fakultät für Biologie, Universität Konstanz, Fach M654, D-78457 Konstanz, Germany.
Arch Microbiol. 1999 Nov;172(5):287-94. doi: 10.1007/s002030050782.
The anaerobic bacterium Desulfobacterium cetonicum oxidized m-cresol completely with sulfate as electron acceptor. During growth, 3-hydroxybenzylsuccinate (identified by gas chromatography/mass spectroscopy and by comparison of high-performance liquid chromatography retention time and UV spectrum with a chemically synthesized reference compound) accumulated in the medium. This finding indicates that the methyl group of m-cresol is activated by addition to fumarate as in the case of anaerobic toluene metabolism. In cell-free extracts of D. cetonicum, the formation of 3-hydroxybenzylsuccinate from m-cresol and fumarate was detected at an activity of 0.5 nmol min(-1) (mg protein)(-1). This reaction depended strictly on anoxic assay conditions. Treatment with air resulted in a complete loss of activity; however, some activity could be recovered after restoring anoxic conditions. The activity was slightly membrane-associated. 3-Hydroxybenzylsuccinate was degraded via CoA thioesterification and further oxidation to 3-hydroxybenzoyl-CoA as subsequent steps in the degradation pathway.
厌氧细菌嗜酮脱硫杆菌以硫酸盐作为电子受体将间甲酚完全氧化。在生长过程中，3 - 羟基苄基琥珀酸（通过气相色谱/质谱鉴定，并通过与化学合成参考化合物比较高效液相色谱保留时间和紫外光谱来确定）在培养基中积累。这一发现表明，间甲酚的甲基如同厌氧甲苯代谢的情况一样，通过加成到富马酸上而被活化。在嗜酮脱硫杆菌的无细胞提取物中，检测到从间甲酚和富马酸形成3 - 羟基苄基琥珀酸的活性为0.5 nmol min⁻¹（mg蛋白质）⁻¹。该反应严格依赖于缺氧的测定条件。用空气处理会导致活性完全丧失；然而，恢复缺氧条件后可恢复一些活性。该活性与膜有轻微关联。3 - 羟基苄基琥珀酸通过辅酶A硫酯化作用降解，并进一步氧化为3 - 羟基苯甲酰辅酶A，这是降解途径中的后续步骤。
