Effect of environmental factors on the trans/cis ratio of unsaturated fatty acids in Pseudomonas putida S12
Effect of environmental factors on the trans/cis ratio of unsaturated fatty acids in Pseudomonas putida S12
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DOI：
10.1128/aem.62.8.2773-2777.1996
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发表时间：
1996-08-01
影响因子：
4.4
通讯作者：
DeBont, JAM
中科院分区：
文献类型：
--
作者：
Heipieper, HJ;Meulenbeld, G;DeBont, JAM
研究了恶臭假单胞菌S12对环境胁迫的膜反应，细胞对6种不同重金属的反应与反式/顺式不饱和脂肪酸比值的增加有关，测定了反式/顺式比值的增加与重金属的毒性效应和细胞膜的非特异性通透性之间的相关性，结果表明，适应甲苯毒性浓度的细胞与未适应的细胞相比，对所有浓度的锌的耐受性都增强了，暴露在不同温度下的细胞在30℃时生长最好。这些细胞的膜脂肪酸饱和程度随着温度的降低而降低。不饱和脂肪酸的反式/顺式比率只有在较高的温度下才会增加，渗透胁迫表现为水分活性的降低，只有在有毒浓度的氯化钠或蔗糖存在时，反式/顺式比率才会增加，在没有施加水分活度的情况下，甘油对反式/顺式比率的显著影响被测量到，当细胞暴露在不同的PHS时，在PHS在4.0到5.0之间有一个明显的最适顺式/反式异构酶活性，而在较高或较低的PHS下没有发生反应，这种最佳的反应与pH 4到5之间的活力损失相吻合。
The membrane reactions of Pseudomonas putida S12 to environmental stress were investigated, Cells reacted to the addition of six different heavy metals with an increase in the ratio of trans to cis unsaturated fatty acids, A correlation among the increase in the trans/cis ratio, the toxic effects of the heavy metals, and nonspecific permeabilization of the cytoplasmic membrane, as indicated by an efflux of potassium ions, was measured, Cells previously adapted to toxic concentrations of toluene exhibited increased tolerance to all applied concentrations of zinc compared with nonadapted cells, Cells exposed to different temperatures grew optimally at 30 degrees C. The degree of saturation of the membrane fatty acids of these cells decreased with decreasing temperature, An increase in the trans/cis ratio of unsaturated fatty acids took place only at higher temperatures, Osmotic stress, expressed as reduced water activity, Was obtained by using different types of solutes, Only in the presence of toxic concentrations of sodium chloride or sucrose did the trans/cis ratio increase, At no applied water activity a significant effect of glycerol on the trans/cis ratio was measured, When cells were exposed to different pHs, a distinct optimum cis/trans isomerase activity was measured at pHs between 4.0 and 5.0, whereas at higher or lower pHs no reaction occurred, This optimum coincided with a Loss of viability between pH 4 and 5.