Bacterial populations in an anthropogenically disturbed stream: Comparison of different seasons
Bacterial populations in an anthropogenically disturbed stream: Comparison of different seasons
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DOI：
10.1007/s002489900173
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发表时间：
1999-10-01
影响因子：
3.6
通讯作者：
Leff, LG
中科院分区：
文献类型：
--
作者：
Lemke, MJ;Leff, LG
为了确定环境变化对河流细菌种群的影响，在不同季节对人为干扰的河流和未受干扰的参考河流的组合和种群水平进行了比较，在受多种环境扰动影响的河流的两个干扰点监测的物理和化学变量证实了三个参考地点的水质明显不同：两个来自相邻的未受干扰的流域，一个来自被污染的河流的源头。装配狂欢变量，包括：细菌总数，菌落形成单位和原位杂交的细菌数量，在受干扰和未受干扰的位点之间只有一个统计显著差异。采用rDNA探针集落杂交法测定了洋葱伯克霍尔德菌、恶臭假单胞菌和钙酸不动杆菌3种细菌的种群水平变化。11月和2月，受干扰地点可培养的钙刺螨丰度较高；不过。和恶臭杆菌没有表现出与污染相关的反应。原位杂交结果表明，11月和4月在参考点有更多的calcoaceticus，表明干扰点的可培养性增加。为了确定地点之间的差异是否归因于溪流之间水质的变化，从受干扰的溪流中分离出三株细菌菌株，在受干扰和参考地点的水中的烧瓶中生长64小时。在河流中观察到，在大约24小时的初始滞后期后，污染的河流中钙酸霉数量增加。我们的结果表明，尽管细菌群落的组合水平测量不能反映不同地点的环境差异，但钙酸霉；受干扰点和参考点之间的种群大小不同，表明人为干扰可以改变某些细菌种群而不改变其他细菌种群。
To determine the effects of environmental changes on stream bacterial populations, assemblage-and population-level measurements were compared between an anthropogenically disturbed stream and an undisturbed reference stream during different seasons, Physical and chemical variables monitored at two disturbed sites from a stream affected by multiple environmental perturbations confirmed discernibly different water quality from three reference sites: two from an adjacent, undisturbed watershed and one hom the headwaters of the polluted stream. Assemblage-revel variables, including: total number of bacteria, colony forming units, and number of Bacteria from in situ hybridization revealed only one statistically significant difference between disturbed and undisturbed sites. Population-level changes of three bacterial species, Burkholderia cepacia, Pseudomonas putida, and Acinetobacter calcoaceticus, were determined by colony hybridization with rDNA probes. Abundance of culturable A. calcoaceticus was higher at: disturbed sites in November and February; B. cepacia. and P. putida did not exhibit pollution-associated responses. In contrast, in situ hybridization indicated that there was more A. calcoaceticus at the reference sites in November and April, suggesting that culturability of the species increased at disturbed sites. To determine if differences among sites were attributable to changes in water quality among the streams, three bacterial strains isolated from the disturbed stream were grown for 64 h in flasks in water from disturbed and reference sites. As observed in the stream, A. calcoaceticus numbers increased in polluted stream water after an initial lag period of approximately 24 h. Our results indicate that although assemblage-level measurements of bacterial communities did not reflect environmental differences among sites, A. calcoaceticus; population sizes differed between disturbed and reference sites, suggesting that anthropogenic disturbance can alter some bacterial populations and not others.