title: Characterization of metabolites in intact Streptomyces citricolor culture supernatants using high-resolution nuclear magnetic resonance and directly coupled high-pressure liquid chromatography-nuclear magnetic resonance spectroscopy.
abstract: A novel NMR spectroscopic approach to the direct biochemical characterization of bacterial culture broths is presented. A variety of one- and two-dimensional 1H NMR spectroscopic methods were used to characterize low-molecular-weight organic components of broth supernatants from cultures of Streptomyces citricolor. By applying 1H NMR spectroscopy to analyze whole, untreated culture supernatants, it was possible to identify and monitor simultaneously a range of media substrates and excreted metabolites. Identified metabolites include 2-phenylethylamine, trehalose, succinate, acetate, uridine, and aristeromycin, a secondary metabolite with antibiotic properties. Directly coupled HPLC-NMR spectroscopy was also applied to the analysis of broth supernatants for the first time, to aid spectral assignments, especially where signals were extensively overlapped in the 1H NMR spectra of the whole broth mixtures. Two-dimensional NMR methods such as 1H-1H correlation spectroscopy, 1H-13C heteronuclear single quantum correlation, and 1H-13C heteronuclear multiple bond correlation aided the structure elucidation and peak assignments of individual components in the mixtures by providing information on 1H-1H coupling networks and 13C chemical shifts. This work shows that high-resolution NMR spectroscopic methods provide a rapid and efficient means of investigating microbial metabolism directly without invasive or destructive sample pretreatment.
authors.affiliation: Biological Chemistry, Division of Biomedical Sciences, Imperial College of Science, Technology, and Medicine, Sir Alexander Fleming Building, South Kensington, London, SW7 2AZ, United Kingdom.
authors.forename: C B
authors.initials: CB
authors.lastname: Abel
authors.forename: J C
authors.initials: JC
authors.lastname: Lindon
authors.forename: D
authors.initials: D
authors.lastname: Noble
authors.forename: B A
authors.initials: BA
authors.lastname: Rudd
authors.forename: P J
authors.initials: PJ
authors.lastname: Sidebottom
authors.forename: J K
authors.initials: JK
authors.lastname: Nicholson
mesh_terms: D019342:Acetic Acid / Q000032:analysis / Q000378:metabolism; D000241:Adenosine / Q000031:analogs & derivatives / Q000032:analysis / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000032:analysis / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D019343:Citric Acid / Q000032:analysis / Q000378:metabolism; D017077:Culture Media, Conditioned / Q000737:chemistry; D005632:Fructose / Q000032:analysis / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D010627:Phenethylamines / Q000032:analysis / Q000378:metabolism; D013302:Streptomyces / Q000378:metabolism*; D019802:Succinic Acid / Q000032:analysis / Q000378:metabolism; D014199:Trehalose / Q000032:analysis / Q000378:metabolism; D014529:Uridine / Q000032:analysis / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D017077:Culture Media, Conditioned; D010627:Phenethylamines; C030034:aristeromycin; D019343:Citric Acid; D005632:Fructose; C029261:phenethylamine; D019802:Succinic Acid; D014199:Trehalose; D000241:Adenosine; D019342:Acetic Acid; D014529:Uridine