Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik, D-7000 Stuttgart 80, Technische Universität Hamburg-Harburg, D-2100 Hamburg 90, and Universität Stuttgart, D-7000 Stuttgart 1, Federal Republic of Germany.
Appl Environ Microbiol. 1989 Nov;55(11):2904-8. doi: 10.1128/aem.55.11.2904-2908.1989.
Strain DM1, a Mycobacterium sp. that utilizes 2,6-xylenol, 2,3,6-trimethylphenol, and o-cresol as sources of carbon and energy, was isolated. Intact cells of Mycobacterium strain DM1 grown with 2,6-xylenol cooxidized 2,4,6-trimethylphenol to 2,4,6-trimethylresorcinol. 4-Chloro-3,5-dimethylphenol prevents 2,6-xylenol from being totally degraded; it was quantitatively converted to 2,6-dimethylhydroquinone by resting cells. 2,6-Dimethylhydroquinone, citraconate, and an unidentified metabolite were detected as products of 2,6-xylenol oxidation in cells that were partially inactivated by EDTA. Under oxygen limitation, 2,6-dimethylhy-droquinone, citraconate, and an unidentified metabolite were released during 2,6-xylenol turnover by resting cells. Cell extracts of 2,6-xylenol-grown cells contained a 2,6-dimethylhydroquinone-converting enzyme. When supplemented with NADH, cell extracts catalyzed the reduction of 2,6-dimethyl-3-hydroxyquinone to 2,6-dimethyl-3-hydroxyhydroquinone. Since a citraconase was also demonstrated in cell extracts, a new metabolic pathway with 2,6-dimethyl-3-hydroxyhydroquinone as the ring fission substrate is proposed.
一株能利用 2,6-二甲酚、2,3,6-三甲酚和邻甲酚作为碳源和能源的分枝杆菌(Mycobacterium sp.)被分离出来。用 2,6-二甲酚培养的分枝杆菌菌株 DM1 的完整细胞能将 2,4,6-三甲基苯酚共氧化为 2,4,6-三甲基间苯二酚。4-氯-3,5-二甲基苯酚能阻止 2,6-二甲酚完全降解；它能被静止细胞定量转化为 2,6-二甲基对苯二酚。2,6-二甲基对苯二酚、柠康酸和一种未鉴定的代谢物被检测为 EDTA 部分失活的细胞中 2,6-二甲酚氧化的产物。在缺氧条件下，2,6-二甲基氢醌、柠康酸和一种未鉴定的代谢物在静止细胞中 2,6-二甲酚转化过程中被释放。用 2,6-二甲酚培养的细胞提取物中含有一种 2,6-二甲基氢醌转化酶。当补充 NADH 时，细胞提取物能催化 2,6-二甲基-3-羟基对苯二酚还原为 2,6-二甲基-3-羟基对苯二酚。由于细胞提取物中也证明存在柠康酸酶，因此提出了一种新的代谢途径，以 2,6-二甲基-3-羟基对苯二酚为环裂解底物。
