Unusual lipid composition of the gram-negative, freshwater, stalked bacterium Caulobacter bacteroides NP-105

• Published in: Biochimica et biophysica acta 1997-08, Vol.1347 (2), p.127-139
• Main Authors: Batrakov, Stanislav G., Nikitin, Denis I., Sheichenko, Vladimir I., Ruzhitsky, Alexandr O.
• Format: Article
• Language: English
• Subjects: Caulobacter - chemistry; Caulobacter bacteroides; Chromatography, Thin Layer; Fatty Acids - analysis; Glucosyl glucuronosyldiacylglycerol; Glucosyldiacylglycerol; Glucuronosyldiacylglycerol; Glycolipid; Glycolipids - analysis; Lipids - analysis; Lipids - isolation & purification; Magnetic Resonance Spectroscopy; Phosphatidyl glucosyldiacylglycerol; Sulfoquinovosyldiacylglycerol
• ISSN: 0005-2760; 0006-3002; 1879-145X
• DOI: 10.1016/S0005-2760(97)00060-X

The extractable lipids of the gram-negative, stalked, freshwater bacterium Caulobacter bacteroides NP-105 account for about 9.5% by weight of dry cells, polar lipids comprising up to 95% of the total. The polar lipids consist of five glycolipids, namely, 1,2-diacyl-3- α- d-glucopyranosyl- sn-glycerol ( I) (34% of the total), 1,2-diacyl-3- α- d-[6′-(1″,2″-diacyl- sn-glycero-3-phospho)]glucopyranosyl- sn-glycerol ( II) (7%), 1,2-diacyl-3- α- d-glucuronopyranosyl- sn-glycerol ( III) (17%), 1,2-diacyl-3- α- d-(6′-sulfo)quinovopyranosyl- sn-glycerol ( V) (9%), and 1,2-diacyl-3- α- d-[4′-( α- d-glucopyranosyl)]glucuronopyranosyl- sn-glycerol ( VI) (28%), and one glycerophospholipid, 1,2-diacyl- sn-glycero-3-phosphoglycerol ( IV) (5%). The main fatty acyls of the lipids are n-16:0, cis-18:1 ω7, and cis-11,12-methyleneoctadecanoic (lactobacillic) acid residue. Of the 6 lipids listed, only 3 ( I, IV, and V) can be treated as widely encountered. However, sulfonic glycolipid V is a characteristic lipid component of photosynthetic organisms rather than non-photosynthetic ones. Phosphatidyl derivatives of glycosyldiacylglycerols of type II normally occur in gram-positive bacteria, among gram-negative bacteria they have been revealed only in two species of the Pseudomonas genus. Glucuronosyl and α-glucosyl- α-glucuronosyl diacylglycerols such as III and VI, respectively, are very rare lipids, the latter being found so far only in a Streptomyces strain.