N-ε-Carboxymethyllysine (CML) is formed during glycation reactions (synonym, Maillard reaction). CML is degraded by the human colonic microbiota, but nothing is known about the formation of particular metabolites. In the present study, six probiotic E. coli strains were incubated with CML in the presence or absence of oxygen in either minimal or nutrient-rich medium. CML was degraded by all strains only in the presence of oxygen. HPLC-MS/MS was applied for identification of metabolites of CML. For the first time, three bacterial metabolites of CML have been identified, namely N-carboxymethylcadaverine (CM-CAD), N-carboxymethylaminopentanoic acid (CM-APA), and the N-carboxymethyl-Δ¹-piperideinium ion. During 48 h of incubation of CML with five different E. coli strains in minimal medium in the presence of oxygen, 37–66% of CML was degraded, while CM-CAD (1.5–8.4% of the initial CML dose) and CM-APA (0.04–0.11% of the initial CML dose) were formed linearly. Formation of the metabolites is enhanced when dipeptide-bound CML is applied, indicating that transport phenomena may play an important role in the “handling” of the compound by microorganisms.

中文翻译：

---

先进的糖化终产物N -ε-羧甲基赖氨酸（CML）通过不同的益生菌大肠杆菌菌株的代谢

N -ε-羧甲基赖氨酸（CML）在糖基化反应（同义词，美拉德反应）期间形成。CML被人结肠菌群降解，但对特定代谢物的形成一无所知。在本研究中，将六种益生菌大肠杆菌菌株在有氧或无氧条件下在基本或营养丰富的培养基中与CML一起孵育。仅在氧气存在下，所有菌株均会降解CML。HPLC-MS / MS用于鉴定CML的代谢产物。首次，CML三个细菌代谢物已被鉴定，即Ñ -carboxymethylcadaverine（CM-CAD），Ñ -carboxymethylaminopentanoic酸（CM-APA），而Ñ -carboxymethyl-Δ ¹-哌啶鎓离子。在有氧条件下，将CML与五种不同的大肠杆菌菌株在基本培养基中孵育48小时，其中37-66％的CML降解，而CM-CAD（初始CML剂量的1.5-8.4％）和CM-CAD降解。 APA（初始CML剂量的0.04-0.11％）是线性形成的。当应用二肽结合的CML时，代谢物的形成会增强，这表明转运现象可能在微生物对化合物的“处理”中起重要作用。