title: Anaerobic carotenoid biosynthesis in Rhodobacter sphaeroides 2.4.1: H2O is a source of oxygen for the 1-methoxy group of spheroidene but not for the 2-oxo group of spheroidenone.
abstract: Anaerobic biosynthesis of carotenoids in the purple facultative photosynthetic bacterium Rhodobacter sphaeroides was studied using mass spectrometry. We have demonstrated that (18)O from H2(18)O was incorporated into the 1-methoxy group of spheroidene and spheroidenone, the two major carotenoids produced by this bacterium during photosynthetic growth. Neither water nor CO2 was shown to provide an oxygen atom for the 2-oxo group of spheroidenone in R. sphaeroides 2.4.1 grown photosynthetically in the absence of molecular oxygen. Possible mechanisms for the anaerobic biosynthesis of spheroidenone in R. sphaeroides are discussed.
authors.affiliation: Department of Microbiology and Molecular Genetics, The University of Texas Health Science Center at Houston Medical School, 77225, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Yeliseev
authors.forename: S
authors.initials: S
authors.lastname: Kaplan
mesh_terms: D000693:Anaerobiosis / Q000502:physiology; D002338:Carotenoids / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism*; D013058:Mass Spectrometry; D010103:Oxygen Isotopes; D010788:Photosynthesis; D012242:Rhodobacter sphaeroides / Q000378:metabolism*; D014867:Water / Q000737:chemistry / Q000378:metabolism*
chemical_list: D010103:Oxygen Isotopes; D014867:Water; C005637:spheroidene; D002338:Carotenoids