Sphingolipid Metabolism inBacteroideaceae

Abstract

The lipid composition of the anaerobic Bacteroides thetaiotaomikron has been analyzed. Sphingomyelin, ceramide phosphinicoethanolamine, free even-numbered and branched chain sphingosine bases and ceramide represented about 50% of the total lipid extract. The main ester phospholipid was phosphatidylethanolamine.The alkali-stable sphingophospholipids were predominantly ./V-acylated with 3-hydroxypalmitic acid, whereas the ester phospholipids are preferentially substituted with normal even and odd-numbered and branched-chain fatty acids.

Role of Sphingolipids in Microbial Pathogenesis

“…Most prokaryotic cells do not contain sphingolipids. However, some bacteria, including the genera Sphingobacterium (99,147,148), Sphingomonas (142,146), and Bacteroides (63,122) and Bdellovibrio stolpii (140) are able to synthesize sphingolipids. Sphingomonas spp.…”

Distribution of Sphingolipids in Bacteroides Species

“…KUNSMAN (2) found phosphosphingolipids in 6 strains of B. ruminicola tested. STOFFEL et al (3) reported the presence of sphingomyelin and ceramide besides ceramide phosphinicoethanolamine in B. thetaiotaomicron. We (4) also examined the extractable lipids of B. fragilis NCTC 9343 and found ceramide phosphorylethanolamine and ceramide.…”

Hydroxy fatty acids in Bacteroides species: D-(--)-3-hydroxy-15-methylhexadecanoate and its homologs

“…Further support derives from the fact that the hydroxy acids are of the D-(-)-3-hydroxy family, which are intermediates of fatty acid biosynthesis, whereas the L-(+)-3hydroxy acids are intermediates of 8-oxidation (11,12,16). Stoffel et al (23) were unable to demonstrate incorporation of radioactivity into "3-hydroxy palmitate" from [1_-4C]palMitate, although label was incorporated into long-chain base fractions. This is consistent with the idea that the hydroxy fatty acids arise by chain elongation.…”

“…In most such reports, no mention is made of the hydroxylated fatty acids, except, perhaps, as a comment that such compounds were not detected (3,6,7,13,14,21), a generally unexpected result. The lone exception is the work of Stoffel et al (23), who reported "3-hydroxyhexadecanoic" acid as a significant component of the cellular fatty acids of Bacteroides thetaiotaomicron.…”