Applied and Environmental Microbiology ( IF 4.4 ) Pub Date : 2020-01-03 Shanati, T., Ansorge-Schumacher, M. B.
The gram-positive soil bacterium Arthrobacter sp. TS-15 (DSM 32400), which is capable of metabolizing ephedrine as a sole source of carbon and energy, was isolated. According to 16S rRNA gene sequences and comparative genomic analysis, Arthrobacter sp. TS-15 is closely related to Arthrobacter aurescens. Distinct from all known physiological paths, ephedrine metabolism by Arthrobacter sp. TS-15 is initiated by the selective oxidation of the hydroxyl function at the α-C-atom, yielding methcathinone as the primary degradation product. Rational genome mining revealed a gene cluster potentially encoding the novel pathway. Two genes from the cluster, which encoded putative short-chain dehydrogenases, were cloned and expressed in Escherichia coli. The obtained enzymes were strictly NAD+-dependent and catalyzed the oxidation of ephedrine to methcathinone. Pseudoephedrine dehydrogenase (PseDH) selectively converted (S,S)-(+)-pseudoephedrine and (S,R)-(+)-ephedrine to (S- and R-)-methcathinone, respectively. Ephedrine dehydrogenase (EDH) exhibited strict selectivity for the oxidation of the diastereomers (R,S)-(–)-ephedrine and (R,R)-(–)-pseudoephedrine.
Importance Arthrobacter sp. TS-15 is a newly isolated bacterium with the unique ability to degrade ephedrine isomers. The initiating steps of the novel metabolic pathway are described. Arthrobacter sp. TS-15 and its isolated ephedrine-oxidizing enzymes have potential for use in decontamination and synthetic applications.
中文翻译:
关节杆菌对麻黄碱异构体的生物降解 TS-15:新型麻黄碱和伪麻黄碱脱氢酶的发现
革兰氏阳性土壤细菌节藻。分离了能够代谢麻黄碱作为唯一碳和能量来源的TS-15(DSM 32400)。根据16S rRNA基因序列和比较基因组分析,节杆菌属。TS-15与金色节杆菌密切相关。与所有已知的生理途径不同,节杆菌属的麻黄碱代谢。TS-15通过在α-C原子处羟基官能团的选择性氧化而引发,从而产生甲卡西酮作为主要降解产物。合理的基因组挖掘揭示了可能编码新途径的基因簇。从该簇中编码了假定的短链脱氢酶的两个基因被克隆并在大肠杆菌。所获得的酶严格地是NAD +依赖性的,并且催化麻黄碱氧化为甲卡西酮。伪麻黄碱脱氢酶(PseDH)分别选择性地将(S,S)-(+)-伪麻黄碱和(S,R)-(+)-麻黄碱分别转化为(S-和R-)-甲卡西酮。麻黄碱脱氢酶(EDH)对非对映异构体(R,S)-(-)-麻黄碱和(R,R)-(-)-伪麻黄碱的氧化表现出严格的选择性。
重要性 节藻。TS-15是一种新近分离的细菌,具有独特的降解麻黄碱异构体的能力。描述了新陈代谢途径的起始步骤。节藻。TS-15及其分离的麻黄碱氧化酶具有用于去污和合成应用的潜力。