Lipid composition of the gram-negative, budding, seawater bacterium Hyphomonas jannaschiana lacking in phospholipids

The extractable polar lipids of the gram-negative, budding, seawater bacterium Hyphomonas jannaschiana VP-2T were shown to consist of five glycolipids, namely, 1,2-diacyl-3-alpha-D-glucopyranosyl-sn-glycerol (I) (25% of the total lipids), 1,2-diacyl-3-alpha-D-glucuronopyranosyl-sn-glycerol (II) (41%), taurine-amide of II (III) (32%), acyl-D-glucuronopyranoside (IV) (0.9%), and acyl-3-O-acyl-D-glucuronopyranoside (V) (0.4%); glycolipid (III) was described by the authors previously. In addition, small amounts of poly(beta-hydroxybutyrate) and free fatty acids were present in the lipids extracted. Neither phospholipids nor low-polarity lipids, such as fatty acid esters of glycerol or fatty alcohols, were detected. Glycolipids I, II, IV, V were isolated in chromatographically pure state by chromatography on DEAE-cellulose and silica-gel columns. Their structures were established using chromatographic, spectrometric and chemical-degradation methods. In glyceroglycolipids I and II, unsaturated fatty acid residues were located predominantly at the sn-1 carbon of the glycerol moiety while saturated ones were linked mainly to the sn-2 carbon.