Links between bacterial production, amino-acid utilization and community composition in productive lakes
Links between bacterial production, amino-acid utilization and community composition in productive lakes
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DOI：
10.1038/ismej.2007.64
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发表时间：
2007-10-01
期刊：
影响因子：
11
通讯作者：
Jorgensen, Niels Ole Gerslev
中科院分区：
文献类型：
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作者：
Bertilsson, Stefan;Eiler, Alexander;Jorgensen, Niels Ole Gerslev
对于自然微生物群落来说，细菌类群的分布和丰度对生态系统功能的影响知之甚少。我们将16S rRNA末端限制性片段长度多态性与细菌产量和精氨酸摄取动力学联系起来，以检验是否可以从群落组成中预测四个湖泊浮游细菌的功能特征。最大精氨酸摄取率(精氨酸V-max)为细菌产量的10%~100%。由于精氨酸的高生长效率(63-77%)，细菌群落可能会使用这种单一的有机底物来潜在地饱和其碳需求，例如，在游离氨基酸突然激增期间。然而，由于这些湖泊中精氨酸的原位浓度很低(<；0.9ug L(-1))，在环境浓度下的实际摄取率很少超过Vmax的10%。细菌产量和精氨酸Vmax可以从细菌核型的子集中预测出来，这些核型暂时隶属于几个细菌科(蓝藻、放线菌、拟杆菌和变形杆菌)。多元统计分析表明，核糖体类型对细菌产量和精氨酸Vmax的预测既有高度重要的，也有次要的。这些种群与各自的功能特征或负或正相关，显示出不同的生态作用。我们的研究提供了一个统计上强有力的证据，除了环境条件外，细菌群落组成的模式也可以用来预测湖泊生态系统的功能。
Influence of distribution and abundance of bacterial taxa on ecosystem function are poorly understood for natural microbial communities. We related 16S rRNA-based terminal restriction fragment length polymorphism to bacterial production and arginine uptake kinetics to test if functional features of bacterioplankton in four lakes could be predicted from community composition. Maximum arginine uptake rate (arginine V-max) ranged from 10% to 100% of bacterial production. Owing to high growth efficiencies on arginine (63-77%), the bacterial community could potentially saturate its carbon demand using this single organic substrate, for example, during sudden surges of free amino acids. However, due to low in situ concentrations of arginine in these lakes (< 0.9 mu g l(-1)), actual uptake rates at ambient concentrations rarely exceeded 10% of Vmax. Bacterial production and arginine Vmax could be predicted from a subset of bacterial ribotypes, tentatively affiliated with several bacterial divisions (Cyanobacteria, Actinobacteria, Bacteroidetes and Proteobacteria). Multivariate statistical analysis indicates that there were both highly important and less important ribotypes for the prediction of bacterial production and arginine Vmax. These populations were either negatively or positively related to the respective functional feature, indicating contrasting ecological roles. Our study provides a statistically robust demonstration that, apart from environmental conditions, patterns in bacterial community composition can also be used to predict lake ecosystem function.