Bacterial adaptation to low-nutrient conditions as studied with algal extracellular products
Bacterial adaptation to low-nutrient conditions as studied with algal extracellular products
复制标题
DOI：
10.1007/bf02010936
复制
发表时间：
1984-09
影响因子：
3.6
通讯作者：
W. H. Bell
中科院分区：
文献类型：
--
作者：
W. H. Bell
动力学分析表明，来自马萨诸塞州伍兹霍尔附近两个海洋环境的天然细菌种群成员具有酶介导的转运系统，该系统允许利用从藻类中肋骨条藻、海链藻和杜氏杜氏藻中制备的14 C标记的细胞外有机C（14 C-EOC），并提供15-150μC·L −1的浓度范围。它表明，以前暴露的细菌EOC从这些藻类不能解释得到的线性动力学模式。因此，在低浓度下利用藻类EOC的能力是代谢活性细菌群体的一般特征。此外，由于天然细菌不将这种能力限制在特定的EOC库中，因此结果与以下假设一致：适应低营养环境的细菌具有高底物亲和力和低底物特异性的摄取系统。研究表明，仅用10 mg·1− 1蛋白胨就能提高底物水平，有利于缺乏这些适应性的细菌种群的发育。标准富集技术通常导致细菌的分离，这些细菌是用于评估天然微生物群生态学的不良模型。
Kinetic analyses indicate that members of natural bacterial populations from 2 marine environments near Woods Hole, MA, possess enzyme-mediated transport systems which permit utilization of14C-labeled extracellular organic C (14C-EOC) prepared from the algae,Skeletonema costatum, Thalassiosira pseudonana, andDunaliella tertiolecta, and supplied over a concentration range of 15–150μC·liter−1. It is shown that previous exposure of the bacteria to the EOC from these algae cannot explain the linear kinetic patterns obtained. Therefore, the ability to utilize algal EOC at low concentrations is a general feature of metabolically active bacterial populations. Further, as the native bacteria do not restrict this ability to a specific EOC pool, the results are consistent with the hypothesis that bacteria adapted to low nutrient environments possess uptake systems of high substrate affinity and low substrate specificity. Elevation of substrate levels with as little as 10 mg·1−1peptone is shown to favor development of a bacterial population that lacks these adaptations. Standard enrichment techniques typically result in the isolation of bacteria that are poor models for evaluating the ecology of native microbiota.