Molecular physiology of sugar catabolism in Lactococcus lactis IL1403
Molecular physiology of sugar catabolism in Lactococcus lactis IL1403
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DOI：
10.1128/jb.183.13.3817-3824.2001
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发表时间：
2001-07-01
影响因子：
3.2
通讯作者：
Cocaign-Bousquet, M
中科院分区：
文献类型：
--
作者：
Even, S;Lindley, ND;Cocaign-Bousquet, M
研究了乳酸乳球菌IL 1403在两种不同培养基上对葡萄糖和半乳糖的生理反应。特定的代谢率的分析表明，尽管显着的变化，在两个增长和糖的消耗率，同型乳酸发酵保持所有的文化，由于低浓度的乳酸-甲酸裂解酶或醇脱氢酶。当将离子载体莫能菌素添加到培养基中时，通过糖酵解的Bur没有增加，这表明分解代谢通量限制，其中，糖酵解中间体的低细胞内浓度和体内糖酵解酶的高能力，可能在糖转运的水平。为了评估转录，一种新的DNA宏阵列技术采用地高辛体外标记的RNA和碱性磷酸酶-antidigoxigenin缀合物的杂交检测。该方法表明，糖酵解的几个基因在葡萄糖上表达到更高的水平，并且混合酸途径的基因在半乳糖上表达到更高的水平。当将酶合成速率与转录物浓度进行比较时，可以推断在葡萄糖上生长的细胞中发生了一些翻译调节，其翻译效率高出三倍。
The metabolic characteristics of Lactococcus lactis IL1403 were examined on two different growth media with respect to the physiological response to two sugars, glucose and galactose. Analysis of specific metabolic rates indicated that despite significant variations in the rates of both growth and sugar consumption, homolactic fermentation was maintained for all cultures due to the low concentration of either pyruvate-formate lyase or alcohol dehydrogenase. When the ionophore monensin was added to the medium, Bur through glycolysis was not increased, suggesting a catabolic flux limitation, which, with the low intracellular concentrations of glycolytic intermediates and high in vivo glycolytic enzyme capacities, may be at the level of sugar transport. To assess transcription, a novel DNA macroarray technology employed RNA labeled in vitro with digoxigenin and detection of hybrids with an alkaline phosphatase-antidigoxigenin conjugate. This method showed that several genes of glycolysis were expressed to higher levels on glucose and that the genes of the mixed-acid pathway were expressed to higher Levels on galactose, When rates of enzyme synthesis are compared to transcript concentrations, it can be deduced that some translational regulation occurs with threefold-higher translational efficiency in cells grown on glucose.