Effect of Growth Temperature and Culture Age on the Lipid Composition of Vibrio cholerae 569 B (Inaba)

Abstract

The relative amounts of the major phospholipids (phosphatidylethanolamine, phosphatidylglycerol and lyso-phosphatidylethanolamine) and fatty acids in Vibrio cholerae 56911 (Inaba) varied with growth temperature and between exponential and stationary phases of growth.The lipid composition of bacteria is a function of such parameters as growth rate (Cronan, 1968;De Siervo, 1969 Gill, 1975). Since most of the lipids are in the membranes, it is likely that these environmentally-induced changes have major physiological significance. The effects of culture age and growth temperature on the lipid content of bacteria are also important, because it is a common practice in experiments to use cells in the exponential phase of growth when they are physiologically most active, or in the stationary phase when the greatest cell mass is obtained. This paper describes the effects of culture age and growth temperature on the phospholipid and fatty-acid composition of Vibrio cholerae 569B (Inaba). METHODSOrganism and growth. Vibrio cholerae 569B (Inaba) was grown in a synthetic medium containing (g 1-l): K2HP0,, 1.0; (NHd,SO,, 1.0; NaCl, 10; Na,S20,, 1.0; MgCl,, 0.048; L-histidine, 0.23; asparagine, 0.5; and glutamic acid, 0.5. The medium was dispensed in IOO ml portions in 250 ml Erlenmeyer flasks; glucose was autoclaved separately and added to a final concentration of 0.1 % (w/v). Flasks were incubated on a rotary shaker at IOO rev./min at 27 "C or 37 "C. Cultures at the desired growth phase were harvested by centrifuging at 4 "C and washed once with distilled water before extracting the lipids.Extraction, separation and analysis of lipids. Lipids were extracted by the modified Bligh & Dyer (1959) procedure described by Rizza, Tucker & White (1970). A suspension of bacteria (approx. 25 mg dry wt) in 50 mM-sodium phosphate buffer, pH 7-6 (50 ml) was mixed with methanol (100 ml) and chloroform (50 ml), shaken vigorously and allowed to stand overnight. Chloroform (50 ml) and 50 ml of 1.0 M-KCl solution containing 0.4 % (vlv) glacial acetic acid were then added and the mixture shaken. After several hours, the

Effect of Growth Temperature on the Lipid Composition of Mycobacterium smegmatis ATCC 607

“…The increase in unsaturation was mainly due to the significant decrease in tuberculostearic acid and increase in an unknown component (Table 1). These results are in accord with earlier findings (Farrell & Rose, 1967;Barran & Miller, 1976;Raziuddin, 1976;Okuyama et al, 1977;Dhariwal et al, 1977). The increase in unsaturation may be due to an increase in the dehydrase/desaturase enzyme (Cronan, 1975) or to the altered activity of enzymes at the lower temperature (Sinensky, 1971).…”

“…The decrease in phosphatidylinositol mannosides and simultaneous increase in phosphatidylethanolamine may have a protective role in maintaining membrane fluidity. Cardiolipin content has previously been found to be higher (Raziuddin, 1976 ;Dhariwal et al, 1977) or lower (De Siervo, 1969;Okuyama et al, 1977) in cells grown at 27 "C compared with those grown at 37 "C; no change in cardiolipin content was noted in this investigation with M . smegmatis.…”

“…However, there was a 90 % increase in phosphatidylethanolamine at 27 "C (Table 1). Others (Raziuddin, 1976;Dhariwal et al, 1977;Okuyama et al, 1977;Khuller, 1977) have noted a decrease in phosphatidylethanolamine at lower temperature, although De Siervo (1 969) observed an increase in E. coli. The decrease in phosphatidylinositol mannosides and simultaneous increase in phosphatidylethanolamine may have a protective role in maintaining membrane fluidity.…”

The Outer Surface Lipoprotein VolA Mediates Utilization of Exogenous Lipids by Vibrio cholerae

“…By using commercially available exogenous lipid sources with acyl chains that cannot be generated by the bacteria de novo , we can monitor the ability of the bacteria to utilize the exogenous lipid in the phospholipid biosynthesis pathway by TLC. Here, we grew cultures in the presence of a mixed sample of either long-chain fatty acids or LPC, predominantly consisting of 18:2 and 18:3 acyl chains; V. cholerae does not synthesize either of these chains de novo (16). When all three strains were grown in LCFA and 2% glucose, an upwards shift in mobility could be observed in all three of the major phospholipids (Fig.…”

Chlorinated fatty acid distribution in Mycobacterium convolutum phospholipids after growth on 1-chlorohexadecane

“…At a growth temperature of 20°C the level of PE was higher with either of the two substrates. The effect of a decreased growth temperature on PE level varies among organisms, increasing in some (5,9,13,25) and decreasing in others (12,15,17,20,22,23). An increase in PE at 20°C has been attributed to a lower turnover rate as the growth temperature decreases (26).…”