title: A novel radio-tolerant astaxanthin-producing bacterium reveals a new astaxanthin derivative: astaxanthin dirhamnoside.
abstract: Astaxanthin is a red ketocarotenoid that exhibits extraordinary health-promoting activities such as antioxidant, anti-inflammatory, antitumor, and immune booster. The recent discovery of the beneficial roles of astaxanthin against many degenerative diseases such as cancers, heart diseases, and exercise-induced fatigue has raised its market demand as a nutraceutical and medicinal ingredient in aquaculture, food, and pharmaceutical industries. To satisfy the growing demand for this high-value nutraceuticals ingredient and consumer interest in natural products, many research efforts are being made to discover novel microbial producers with effective biotechnological production of astaxanthin. Using a rapid screening method based on 16S rRNA gene, and effective HPLC-Diodearray-MS methods for carotenoids analysis, we succeeded to isolate a unique astaxanthin-producing bacterium (strain TDMA-17(T)) that belongs to the family Sphingomonadaceae (Asker et al., Appl Microbiol Biotechnol 77: 383-392, 2007). In this chapter, we provide a detailed description of effective HPLC-Diodearray-MS methods for rapid analysis and identification of the carotenoids produced by strain TDMA-17(T). We also describe the methods of isolation and identification for a novel bacterial carotenoid (astaxanthin derivative), a major carotenoid that is produced by strain TDMA-17(T). Finally, we describe the polyphasic taxonomic analysis of strain TDMA-17(T) and the description of a novel species belonging to genus Sphingomonas.
authors.affiliation: Faculty of Agriculture, Food Science and Technology Department, Alexandria University, Alexandria, Egypt. dasker10@gmail.com
authors.forename: Dalal
authors.initials: D
authors.lastname: Asker
authors.forename: Tarek S
authors.initials: TS
authors.lastname: Awad
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Beppu
authors.forename: Kenji
authors.initials: K
authors.lastname: Ueda
mesh_terms: D002851:Chromatography, High Pressure Liquid; D013058:Mass Spectrometry; D008855:Microscopy, Electron, Scanning; D010802:Phylogeny; D011836:Radiation Tolerance; D020578:Sphingomonas / Q000378:metabolism* / Q000648:ultrastructure; D024341:Xanthophylls / Q000096:biosynthesis
chemical_list: D024341:Xanthophylls; C005948:astaxanthine