Critical role of anteiso-C-15:0 fatty acid in the growth of Listeria monocytogenes at low temperatures
Critical role of anteiso-C-15:0 fatty acid in the growth of Listeria monocytogenes at low temperatures
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DOI：
10.1128/aem.63.10.3887-3894.1997
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发表时间：
1997-10-01
影响因子：
4.4
通讯作者：
Wilkinson, BJ
中科院分区：
文献类型：
--
作者：
Annous, BA;Becker, LA;Wilkinson, BJ
单核细胞增生李斯特菌是一种能够在冷藏温度下生长的食源性病原体，膜脂脂肪酸是充分流动的膜状态以允许在低温下生长的主要决定因素。l . monocytogenes由脂肪酸特征剖面主导一个不同寻常的程度(> 95%)的支链脂肪酸,与主要的脂肪酸被anteiso-C-15:0 anteiso-C-17:0,和iso C-15:0文化生长在复杂或媒体在37摄氏度,定义的脂肪酸组成测定l . monocytogenes 10403年代和SLCC 53生长温度范围45到5摄氏度显示两种模式的适应的脂肪酸成分降低增长的温度:(1)脂肪酸链长度的缩短和(2)从iso到anteiso分支的改变。两个转座子tn917诱导的低温下不能生长的冷敏感突变体的脂肪酸组成发生了显著变化，低水平的i-C-15:0、a-C-15:0和a-C-17:0和高水平的i-C-14:0、C-14:0、i-C-16:0和C-16:0。在培养基中添加2-甲基丁酸可以恢复a-C-15:0和a-C-17:0的水平以及在低温下生长的能力，这可能是因为它是甲基丁基辅酶a的前体，甲基丁基辅酶a是合成前奇数脂肪酸的引物。当在37℃下生长的指数期中期的10403S细胞温度下降到5℃时，它们大部分能够，在膜脂肪酸组成重置为更典型的低温生长组成之前重新启动生长。目前还没有发现明显的证据表明脂肪酸不饱和在单核增生乳杆菌对低温的适应中起作用。在低温下，由a- c -15:0主导的脂肪酸结构的转变，以及a- c -15:0缺乏与冷敏感性的关联，使人们关注到这种脂肪酸在单核增生乳杆菌在低温下生长中的关键作用，可能是通过其物理性质及其维持液体的作用。膜脂的液晶状态。
Listeria monocytogenes is a food-borne pathogen capable of growth at refrigeration temperatures, Membrane lipid fatty acids are major determinants of a sufficiently fluid membrane state to allow growth at low temperatures. L. monocytogenes was characterized by a fatty acid profile dominated to an unusual extent (>95%) by branched-chain fatty acids, with the major fatty acids being anteiso-C-15:0, anteiso-C-17:0, and iso C-15:0 in cultures grown in complex or defined media at 37 degrees C, Determination of the fatty acid composition of L. monocytogenes 10403S and SLCC 53 grown over the temperature range 45 to 5 degrees C revealed two modes of adaptation of fatty acid composition to lower growth temperatures: (i) shortening of fatty acid chain length and (ii) alteration of branching from iso to anteiso. Two transposon Tn917-induced cold-sensitive mutants incapable of growth at low temperatures had dramatically altered fatty acid compositions with low levels of i-C-15:0, a-C-15:0, and a-C-17:0 and high levels of i-C-14:0, C-14:0, i-C-16:0, and C-16:0. The levels of a-C-15:0 and a-C-17:0 and the ability to grow at low temperatures were restored by supplementing media with 2-methylbutyric acid, presumably because it acted as a precursor of methylbutyryl coenzyme A, the primer for synthesis of anteiso odd-numbered fatty acids, When mid-exponential-phase 10403S cells grown at 37 degrees C were temperature down-shocked to 5 degrees C they were able, for the most part, to reinitiate growth before the membrane fatty acid composition had reset to a composition more typical for low-temperature growth. No obvious evidence was found for a role for fatty acid unsaturation in adaptation of L. monocytogenes to cold temperature, The switch to a fatty acid profile dominated by a-C-15:0 at low temperatures and the association of cold sensitivity with deficiency of a-C-15:0 focus attention on the critical role of this fatty acid in growth of L. monocytogenes in the cold, presumably through its physical properties and their effects, in maintaining a fluid, liquid-crystalline state of the membrane lipids.