Differences in Metabolism between the Biofilm and Planktonic Response to Metal Stress
Differences in Metabolism between the Biofilm and Planktonic Response to Metal Stress
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DOI：
10.1021/pr2002353
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发表时间：
2011-07-01
影响因子：
4.4
通讯作者：
Weljie, Aalim M.
中科院分区：
文献类型：
--
作者：
Booth, Sean C.;Workentine, Matthew L.;Weljie, Aalim M.
众所周知，细菌生物膜比同一物种的浮游培养物更能抵抗有毒金属的影响。这种现象归因于自由游泳人群中不存在的固着生活方式的许多特征，但细胞内代谢的贡献之前尚未被研究过。在这里，我们使用组合的 GC MS 和 (1)H NMR 代谢组学方法来量化暴露于铜离子的多金属抗性细菌荧光假单胞菌的生物膜和浮游培养物中的全细胞代谢。与浮游培养物相比，生物膜中金属暴露引起的代谢变化显着不同。浮游代谢表明氧化应激反应，其特征是 TCA 循环、糖酵解、丙酮酸、烟酸和烟酰胺代谢的变化。在生物膜中没有观察到类似的代谢变化，而是由胞外多糖相关代谢的变化主导，这表明生物膜中的金属应激诱导保护性反应，而不是在浮游细胞中观察到的反应性变化。从这些结果中，我们得出结论，差异代谢变化在生物膜特异性多金属耐药性和耐受性中发挥作用。对金属毒性的代谢反应的改变代表了越来越多的生物膜特异性机制来抵抗环境压力的新补充。
Bacterial biofilms are known to withstand the effects of toxic metals better than planktonic cultures of the same species. This phenomenon has been attributed to many features of the sessile lifestyle not present in free-swimming populations, but the contribution of intracellular metabolism has not been previously examined. Here, we use a combined GC MS and (1)H NMR metabolomic approach to quantify whole-cell metabolism in biofilm and planktonic cultures of the multimetal resistant bacterium Pseudomonas fluorescens exposed to copper ions. Metabolic changes in response to metal exposure were found to be significantly different in biofilms compared to planktonic cultures. Planktonic metabolism indicated an oxidative stress response that was characterized by changes to the TCA cycle, glycolysis, pyruvate and nicotinate and niacotinamide metabolism. Similar metabolic changes were not observed in biofilms, which were instead dominated by shifts in exopolysaccharide related metabolism suggesting that metal stress in biofilms induces a protective response rather than the reactive changes observed for the planktonic cells. From these results, we conclude that differential metabolic shifts play a role in biofilm-specific multimetal resistance and tolerance. An altered metabolic response to metal toxicity represents a novel addition to a growing list of biofilm-specific mechanisms to resist environmental stress.