Comparison of the phospholipid composition of Bifidobacterium and Lactobacillus strains.

Phospholipid composition of 10 Bifidobacterium strains of human intestinal origin and of 9 Lactobacillus strains was determined by quantitative two-dimensional thin-layer chromatography. Phospholipids of three Bifidobacterium strains from honey bees and of two strains from bovine rumen liquor were qualitatively investigated. Diphosphatidylglycerol and phosphatidylglycerol were present in strains of both genera. All Bifidobacterium strains contained as specific phospholipids a new polyglycerolphospholipid, compound 15, and its lyso derivatives, earlier detected in B. bifidum var. pennsylvanicus. Also, lyso compounds of diphosphatidylglycerol and alanyl phosphatidylglycerol were only present in this genus in variable amounts. Lysyl phosphatidylglycerol was the only ninhydrin-positive phospholipid in seven Lactobacillus strains. In L. delbrückii and L. helveticus it was absent and partially replaced by an unidentified ninhydrin-negative phospholipid. The differences in phospholipid composition between bifidobacteria and lactobacilli may be another argument to differentiate these two genera.