Control of membrane lipids in Mycoplasma gallisepticum: effect on lipid order

Mycoplasma canadense and Mycoplasma verecundum were cultured in a serum-free medium containing bovine serum albumin, cholesterol, oleic acid, and palmitic acid in order to avoid the addition of horse serum. Growth was detected by measurement of A640 and by colony formation. The level of growth attained in this medium was less than that obtained in the horse serum-supplemented media, but colonies retained their distinctive morphology.

supporting

confidence: 87%

Conditions for growing Mycoplasma canadense and Mycoplasma verecundum in a serum-free medium

Muñoz

Sotomayor

1990

“…The toxicity of ethanol was ruled out since we found that the amounts incorporated were not inhibitory to these mycoplasmas. In contrast, LeGrimellec et al were able to grow M. gallisepticum in serum-free modified Edward medium containing an ethanolic cholesterol suspension (8). However, the basal compositions and supplements of the two formulations differ.…”

Section: Discussionmentioning

confidence: 93%

“…However, some Mycoplasma species have been grown with serum-free media when the transport, composition, and fluidity of mycoplasma membranes were being investigated (4,8,12). Kahane and Razin (7) showed that liposomes can serve as a carrier of cholesterol; however, their experiments were completed within 17 to 24 h, mycoplasma growth was estimated by measuring changes in optical density, and the organisms were not serially transferred in serum-free medium.…”

mentioning

confidence: 99%

Liposomes replace serum for cultivation of fermenting mycoplasmas

Cluss¹,

Johnson²,

Somerson³

1983

Cholesterol and albumin are limiting factors in the growth of Mycoplasma species. These nutrients are usually supplied in the culture medium by the addition of serum. The growth of M. pneumoniae in a serum-free medium containing an ethanolic cholesterol suspension and albumin was about one-half the level attained in serum-containing medium. M. gallisepticum and M. fermentans were not cultivable in the cholesterol suspension medium even after supplements were included. In another culture medium containing phosphatidylcholine-cholesterol liposomes and albumin as serum replacements, the growth of M. pneumoniae was approximately equal to that in serum-containing medium, and the growth of M. gallisepticum and M. fermentans was significantly greater than that in medium containing serum. M. fermentans produced even higher yields in liposome medium supplemented with arginine. These fermenting mycoplasmas readily adapted to the liposome medium and by the fifth or sixth serial passage produced thick confluent growth on the lower surface of culture bottles. To obtain maximum growth, we serially transferred the mycoplasmas at least 10 times in serum-free medium before quantitations of growth were made. This is the first report of a serum-free mycoplasma medium of high growth-promoting ability.

“…Replacement of serum with defatted albumin, sterols, phospholipids, and fatty acids (5,23) has greatly simplified the composition of the growth medium. These substitutions are particularly helpful for investigations of mycoplasma lipid metabolism (7) and membrane chemistry (12,18), cases in which a defined lipid composition is essential.…”

mentioning

confidence: 99%

Interaction of albumin and phospholipid:cholesterol liposomes in growth of Mycoplasma spp

Cluss¹,

Somerson²

1986

Mycoplasma spp., sterol and fatty acid auxotrophs, are conventionally grown in complex media containing high concentrations of serum. Serum supplies the required lipids, but its presence complicates studies on the metabolism and antigenicity of mycoplasmas as well as the membrane dynamics of these organisms. In the present work, fetal bovine serum was replaced with dilipidated albumin and liposomes containing high concentrations of cholesterol. The liposomes were produced from phosphatidylcholine which contained other lipid species, including phosphatidylethanolamine, phosphatidylglycerol, and cholesterol. Other liposomes containing cholesterol and one phospholipid yielded significantly less growth of Mycoplasma gallisepticum, indicating that several phospholipids are required to achieve growth levels comparable to those obtained with complex medium. The sources and concentrations of cholesterol, albumin, phosphatidylcholine, and other phospholipids and the interactions among them were important affectors of mycoplasmal growth. Optimal lipid and albumin conditions established for M. gaUlisepticum were then used to propagate five diverse Mycoplasma spp. to growth levels which equalled or surpassed those obtained with medium containing 17% fetal bovine serum.