title: Lipids of extremely halophilic archaeobacteria from saline environments in India: a novel glycolipid in Natronobacterium strains.
abstract: Several strains of extremely halophilic archaeobacteria, both non-alkaliphilic and alkaliphilic, including Halobacterium, Haloferax and Natronobacterium species, were isolated from salt locales in India. The major phospholipids in these strains were the C20-C20-glycerol diether analogues of phosphatidylglycerolmethylphosphate (PGP-Me), phosphatidylglycerol (PG) and phosphatidic acid (PA). In addition, the Halobacterium strains possessed the characteristic glycolipids, sulfated triglycosyl and tetraglycosyl diethers (S-TGD-1 and S-TeGD, respectively) and the unsulfated triglycosyl diether (TGD-1); and the Haloferax strains had the characteristic sulfated and unsulfated diglycosyl glycerol diethers (S-DGD-1 and DGD-1, respectively). The PGP-Me, and PG components of the haloalkaliphiles each occurred as two molecular species with C20-C20- and C20-C25-(isopranoid) glycerol diether lipid cores. In contrast to previous reports of the absence of glycolipids in natronobacteria, the Natronobacterium strains from India were found to contain small amounts of a novel glycolipid identified as glucopyranosyl-1-->6-glucopyranosyl-1-->1-glycerol diether (DGD-4). The lipid cores of DGD-4 also contained mainly unhydroxylated or hydroxylated C20-C20, C20-C25 and C25-C25 molecular species with unsaturated (isoprenoid) chains. Hydroxylated lipid cores have previously been identified only in some methanogenic archaeobacteria.
authors.affiliation: Department of Biochemistry, University of Ottawa, Canada.
authors.forename: V N
authors.initials: VN
authors.lastname: Upasani
authors.forename: S G
authors.initials: SG
authors.lastname: Desai
authors.forename: N
authors.initials: N
authors.lastname: Moldoveanu
authors.forename: M
authors.initials: M
authors.lastname: Kates
mesh_terms: D002240:Carbohydrate Sequence; D005995:Glyceryl Ethers / Q000737:chemistry / Q000302:isolation & purification*; D006017:Glycolipids / Q000737:chemistry / Q000302:isolation & purification*; D016931:Halobacteriales / Q000737:chemistry* / Q000302:isolation & purification; D006217:Halobacterium / Q000737:chemistry / Q000302:isolation & purification; D007194:India; D008055:Lipids / Q000032:analysis*; D008563:Membrane Lipids / Q000032:analysis; D008969:Molecular Sequence Data; D010743:Phospholipids / Q000032:analysis; D012623:Seawater; D012965:Sodium Chloride; D014871:Water Microbiology
chemical_list: D005995:Glyceryl Ethers; D006017:Glycolipids; D008055:Lipids; D008563:Membrane Lipids; D010743:Phospholipids; D012965:Sodium Chloride