title: A variety of glycolipids in green photosynthetic bacteria.
abstract: The compositions of glycolipids in the following seven strains of green photosynthetic bacteria were investigated at the molecular level using LC-MS coupled with an evaporative light scattering detector: Chlorobium (Chl.) limicola strains Larsen (30 °C as the optimal cultivation temperature) and DSM245 (30 °C), Chlorobaculum (Cba.) tepidum strain ATCC49652 (45 °C), Cba. parvum strain NCIB8327 (30 °C), Cba. limnaeum strain 1549 (30 °C), Chl. phaeovibrioides DSM269 (30 °C), and Chloroflexus (Cfl.) aurantiacus strain J-10-fl (55 °C). Dependence of the molecular structures of glycolipids including the chain-length of their acyl groups upon bacterial cultivation temperatures was clearly observed. The organisms with their optimal temperatures of 30, 45, and 55 °C dominantly accumulated glycolipids possessing the acyl chains in the range of C(15)-C(16), C(16)-C(17), and C(18)-C(20), respectively. Cba. tepidum with an optimal temperature of 45 °C preferred the insertion of a methylene group to produce finally a C(17)-cyclopropane chain. Cfl. aurantiacus cultured optimally at 55 °C caused a drastic increase in the chain-length. Notably, the length of such acyl groups corresponded to that of the esterifying chain in the 17-propionate residues of self-aggregative bacteriochlorophylls-c/d/e, indicating stabilization of their supramolecular structures through hydrophobic interactions among those hydrocarbon chains. Based on the detailed compositions of glycolipids, a survival strategy of green photosynthetic bacteria grown in the wide range of temperatures is discussed.
authors: Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan.
authors: Tadashi
authors: T
authors: Mizoguchi
authors: Jiro
authors: J
authors: Harada
authors: Taichi
authors: T
authors: Yoshitomi
authors: Hitoshi
authors: H
authors: Tamiaki
mesh_terms: D041883:Chlorobium / Q000737:chemistry* / Q000502:physiology; D041861:Chloroflexus / Q000737:chemistry* / Q000502:physiology; D008401:Gas Chromatography-Mass Spectrometry; D006017:Glycolipids / Q000737:chemistry* / Q000502:physiology; D015394:Molecular Structure; D013696:Temperature
chemical_list: D006017:Glycolipids