Free lipids were extracted from Brucella melitensis and Bordetella pertussis and their compositions compared with one another. The bacteria contained 1.6% and 8.1% free lipids by dry weight of the respective species.The major component of the neutral lipids of Bruc. melitensis was coenzyme Q10 (0.6 μmol/g bacterial dry weight). Smaller amounts of 1,2‐ and 1,3‐diglycerides and of fatty acyl monoesters of ethanediol and of unknown α‐glycols have been found among the neutral lipids of Bruc. melitensis. The major component of the neutral lipids of Bord. pertussis was a fraction of unesterified fatty acids. Moreover, coenzyme Q8 (0.2 μmol/g bacterial dry weight) was identified in Bord. pertussis. Almost all saponifiable lipids of Bruc. melitensis contained considerable amounts of a C19‐cyclopropane acid (lactobacillic acid) whereas no cyclopropane acid was found among the unesterified fatty acids of Bord. pertussis.From the polar lipid fraction of Bruc. Melitensis diphosphatidylglycerol (cardiolipin), phosphatidylglycerol, phosphatidylethanolamine (cephalin), phosphatidylcholin (lecithin) and phosphatidylserine were isolated; the phosphatidylethanolamine fraction also contained phosphatidyl‐N‐methylethanolamine and phosphatidyl‐N, N‐dimethylethanolamme. Phosphatidylcholine was the major component (37.6% of all phospholipids) in Bruc. melitensis. Determination of positional distribution of the component fatty acids revealed lactobacillic acid to be preferentially located in the number 2‐positions of all phospholipids, while the 1‐positions were preferentially occupied by palmitic acid and in most phospholipids, also by hexadecenoic acid.From Bord. Pertussis, diphosphatidylglycerol, phosphatidylethanolamine, and phosphatidylserine were isolated, but no phosphatidylcholine, no partially methylated phosphatidylethanolamine, and no phosphatidylinositol were found. Palmitic acid was located more frequently at the number 1‐positions, hexadecenoic acid more frequently at the number 2‐positions of the phospholipids. Diphosphatidylglycerol and phosphatidylethanolamine probably contained minor amounts of a C19‐cyclopropane acid.An ornithine‐containing lipid was isolated from Bruc. melitensis and Bord. pertussis. Besides ornithine these lipids contained ethanediol and fatty acids. A similar finding is recorded in Bruc. abortus. Ethanediol appeared to be ester linked to ornithine and to a fatty acid. Another fatty acid is probably linked to one of the amino groups of ornithine by an amide bond. In Bruc. melitensis and Bruc. abortus lactobacillic acid is predominantly ester linked, while palmitic and stearic acids are predominantly amide linked. There is no lactobacillic acid at all in the ornithine lipid of Bord. pertussis. No hydroxy fatty acid has been found in the ornithine lipids of any strain.From the lipid patterns of Bruc. melitensis, of Bruc. abortus studied previously, and of Bord. pertussis we conclude that it is probably not justified to include Brucellae and Bordetellae in the one natural family of Brucellaceae.

Thiele, O. W., & Schwinn, G. (1973). The Free Lipids of Brucella melitensis and Bordetella pertussis. European Journal of Biochemistry, 34(2), 333–344. Portico.