title: Tubercle bacilli generate a novel cell wall-associated pigment after long-term anaerobic culture.
abstract: Many cases of tuberculosis result from reactivation of previously acquired latent infections. Models to study such persister forms often involve gradual depletion of oxygen during culture as poor aeration is a characteristic of non-progressive TB granulomas. Anaerobically cultured bacilli develop a thickened outer-most cell wall layer. Here, we analyzed this layer from anaerobically cultured Mycobacterium tuberculosis and Mycobacterium bovis BCG. By six weeks of anaerobiosis a pigment was detected at levels > 60-fold higher in anaerobic than aerobic bacilli. This pigment was responsible for the electron-dense appearance of the thickened cell wall layer and gave an electrospray mass spectrometry peak at 409 Da (M+Na)+ or (M+H)+. We termed this pigment APP1, anaerobically produced pigment 1, the first pigment identified in M. tuberculosis.
authors.affiliation: Birmingham Centre for Immune Regulation, University of Birmingham, Birmingham B15 2TT, UK. a.f.Cunningham@bham.ac.uk
authors.forename: Adam F
authors.initials: AF
authors.lastname: Cunningham
authors.forename: Peter R
authors.initials: PR
authors.lastname: Ashton
authors.forename: Claire L
authors.initials: CL
authors.lastname: Spreadbury
authors.forename: David A
authors.initials: DA
authors.lastname: Lammas
authors.forename: Rachel
authors.initials: R
authors.lastname: Craddock
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Wharton
authors.forename: Paul R
authors.initials: PR
authors.lastname: Wheeler
mesh_terms: D000693:Anaerobiosis; D002473:Cell Wall / Q000737:chemistry / Q000648:ultrastructure; D000431:Ethanol / Q000737:chemistry; D008970:Molecular Weight; D009163:Mycobacterium bovis / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D009169:Mycobacterium tuberculosis / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D010860:Pigments, Biological / Q000032:analysis* / Q000096:biosynthesis / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D013997:Time Factors
chemical_list: D010860:Pigments, Biological; D000431:Ethanol