Studies of Inorganic Nutrient Limitation in Planktonic Bacteria

浮游细菌无机营养限制的研究

• 批准号: 9020684
• 负责人: William Lewis
• 金额: $ 17.5万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-02-01 至 1993-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9020684&HistoricalAwards=false
• 关键词: Studies; Inorganic; Nutrient; Limitation; Planktonic

The growth of planktonic bacteria is generally assumed to be limited by depletion of organic carbon substrate. In contrast to this assumption, experimental work with natural bacterioplankton populations in Colorado lakes over the past several years show that growth of bacteria in these lakes is frequently limited by phosphorus. This proposal outlines a plan for testing the hypothesis that phytoplankton possess greater phosphorus storage capacity than bacteria, which offsets the kinetic superiority of bacteria under some conditions. Experiments will document (1) the phosphorus inventory of bacteria under nutrient-sufficient and nutrient-deficient conditions, (2) the uptake rate of phosphorus through both inorganic and natural organic phosphorus fractions by bacteria and by co-occurring phytoplankton assemblages, and (3) the phosphorus usage of bacteria and phytoplankton components in mixed communities for which organic phosphorus is the only phosphorus source, or for which inorganic phosphorus is supplied in a pulse, as might occur through nutrient patchiness in nature. The combined outcome of these three sets of experiments will demonstrate the influence of phosphorus storage capacity on the outcome of phosphorus competition between bacteria and phytoplankton.

浮游细菌的生长通常被认为受到有机碳底物消耗的限制。与这种假设相反，过去几年在科罗拉多湖泊中对天然浮游细菌种群进行的实验表明，这些湖泊中细菌的生长经常受到磷的限制。该提案概述了一项计划，以测试浮游植物比细菌具有更大的磷储存能力的假设，这在某些条件下抵消了细菌的动力学优势。实验将记录：(1)营养充足和营养缺乏条件下细菌的磷库存；(2)细菌和共生浮游植物组合通过无机和天然有机磷组分吸收磷的速率；(3)混合群落中细菌和浮游植物组分对磷的利用，其中有机磷是唯一的磷源，或者无机磷是在脉冲中供应的，这可能是由于自然界的营养斑块而发生的。这三组实验的综合结果将证明磷储存能力对细菌和浮游植物之间磷竞争结果的影响。