Bacterioplankton abundance and growth in a river-dominated estuary: relationships with temperature and resources

Aquatic Microbial Ecology

George B. McManus¹  Jonathan R. Pennock¹  Patrick M. Griffin¹ 

关键词: Bacteria;    Mobile Bay;    Gulf of Mexico;    Thymidine;    Epifluorescence;    Seawater culture;   

DOI  :  10.3354/ame037023

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: We measured bacterial abundance and productivity, along with other biological, chemical, and physical variables, during a 17 mo study in Mobile Bay, USA. Mobile Bay is a shallow, river-dominated estuary, with highly variable freshwater inputsand relatively short freshwater residence time (ca. 2 to 3 wk). In addition to the field measurements, we performed bioassay experiments to evaluate the degree of resource limitation of the bacterioplankton. As in other seasonally variable estuaries,temperature appeared to be an important regulator of bacterioplankton in Mobile Bay, with minima in abundance and growth rates occurring during winter. The bioassay experiments, in which an inoculum of the natural bacterioplankton community was dilutedinto filtered bay water and incubated for 4 d, always resulted in rapid net growth, indicating the presence of labile substrates. The net yield of bacterial cells in these assays was always equal to or greater than the abundance of in situpopulations, suggesting that an amount of substrate about equal to in situ biomass divided by growth efficiency was present year round. During winter, the yields in the bioassays were highest, suggesting an accumulation of resources when bacterialgrowth was limited by temperature.

【 授权许可】

Unknown