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SUMMARYI. The phospholipids of Staphylococcus aweus were fractionated on silicic acid columns. The major compounds all appeared to be polyglycerol lipids. Diphosphatidyl glycerol and phosphatidyl glycerol were identified by comparison with the synthetic phospholipids.2. An amino acid derivative of phosphatidyl glycerol was isolated in pure form and shown to be identical with an L-lysine ester of r,z-diacyl-glycero-3-phosphoryl-I'-glycerol.3. The content and composition of phospholipids of Staphylococcus aweus were found to depend on the pH of the medium. In cells harvested at pH 7.0 phosphatidyl glycerol was the major phospholipid, whereas the lysine ester of phosphatidyl glycerol appeared to prevail below pH 5. Under certain conditions a relative increase in diphosphatidyl glycerol was observed. These alterations in the phospholipid pattern of the bacterial culture were reversible.4. Cells of Streptococcus faecalis manifested a comparable shift in the ratio of phosphatidyl glycerol and its lysine ester, but not all bacterial species studied responded in a similar way upon exposure to an acidic environment.The phospholipid composition of Eubacteriaceae is known to differ significantly from that of other organisms. With a few exceptions choline containing phospholipids are lacking, while a number of bacterial species exhibit a rather low content of other types of amphiphatic phospholipids, certain negatively charged components being predominant (for references see I). On the other hand some bacteria appear to produce more complex phospholipids which may compensate for the absence of simple phosphoglycerides containing a nitrogenous moiety. Of particular interest are the amino acid esters of phosphatidyl glycerol, since these compounds have been found to contain substantial quantities of basic amino acids2s3. Staphylococcus aweus has been demonstrated to contain as major phospholipids phosphatidyl glycerol (PG) and its 0-lysine ester (lys-PG) 2+. It appeared possible to govern the ratio between both differently charged phospholipids in this bacterium4 which gave opportunities

This paper describes the outline and first results of an international study to investigate the effect of a reasonable amount of dietary fish on some aspects of cardiovascular risk. In Maastricht and Zeist, The Netherlands, and Tromsø, Norway, healthy male volunteers were given a dietary supplement consisting of 100 g/d of mackerel or meat for a 6-wk period. Compliance was monitored on the basis of the urinary excretion of lithium, which was added to the supplements. Average compliance was approximately 80% and this decreased slightly in time. Systolic blood pressure decreased in both groups to a comparable degree; consequently no specific effect of the fish supplement was observed. The fish supplement significantly prolonged bleeding times. Hematology was hardly affected but platelet counts decreased significantly. No indications were obtained for adverse effects of the fish supplement.

During an investigation on the influence of nutritional environment on the phospholipids of some bacteria the addition of glucose was found to cause the most significant effects. When Bacillus megatherium was cultured in a broth containing glucose, a phospholipid was produced, which was not detected when the bacteria were grown in medium depleted of glucose. The compound appeared to belong to the class of amino acid esters of phosphatidylglycerol (PG) 1 and proved to be identical to PG ornithine ~ previously isolated from B. cereus 3. Similar observations were made on staphylococcus aureus, whose major phospholipids included a polyglycerolphospholipid identical with or related to diphosphatidylglycerol 4, PG 4 and an amino acid derivative of PG 1. The latter compound, PGL, appeared to contain the amino acid lysine. A similar observation had been made recently by MACFARLANE s. In the presence of glucose the amount of PGL produced by S. aureus was increased, the increase being balanced by a decrease of the relative amount of PG. Further studies demonstrated that the shift in the phospholipid distribution in this bacterium must be attributed to a lowering of the pH of the medium as a result of the fermentation of the added glucose.The results of three somewhat different types of experiment, which support this conclusion, are presented in Fig. i. (A) Cultivation of S. aureus in a radioactive broth s enriched with glucose (5 g/l) changed the pH from 7.2 to 4.8 during I6 h incubation at 37 °. Analysis of the phospholipids e at the end of this period revealed the presence of a high amount of PGL. However, when the pH of the medium was restored to the initial value (7.2) by the addition of NaOH, and the bacterial suspension was incuDated another 3 h at this pH, a different phospholipid pattern resulted. A significant decrease of PGL accompanied by an increase of PG was observed.(B) S. aureus grown without glucose in the medium exhibited PG as dominant phospholipid, whereas only a small amount of the amino acid ester derivative was present. The pH of the medium had changed from 7.2 to 7.4. When the pH was subsequently adjusted to 4.8 and the bacterial culture was kept for 3 h at 37 °, a significant increase in the amount of PGL at the cost of PG was demonstrated.(C) A crucial experiment was made by culturing S. aureus with and without glucose at pH 7.2 and 5.2 respectively. Under the first conditions, the pH of the medium decreased because glucose was present, but was prevented from falling below 6.2. The phospholipid fraction of the harvested bacteria contained PG as major compound, whereas according to expectation the amount of PGL was relatively small. Abbreviations: PG, phosphatidylglycerol; PGL, phosphatidylglyceryllysine. Biochim. Biophys. Acta, 84 (1964) 97Since at pH 4.8 S. aureus does not grow adequately the bacteria were cultured at pH 5.2 without glucose and brought to pH 4.8 at the end of the logarithmic phase. Then the bacteria appeared to contain PGL as a major phospholipid, whereas PG itself was prese...

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