Mechanisms of Competition and Coexistence in Freshwater Algae and Bacteria

淡水藻类和细菌的竞争与共存机制

• 批准号: 9418096
• 负责人: James Grover
• 金额: $ 12.49万
• 依托单位: University of Texas at Arlington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-02-15 至 1999-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9418096&HistoricalAwards=false
• 关键词: Mechanisms; Competition; Coexistence; Freshwater; Algae

9418096 Grover Different species of organisms compete for the resources needed for growth. Theoretically, such competition can lead to extinction of all species but the best competitor. Algae and bacteria in freshwater habitats often compete for dissolved phosphorus, an essential nutrient, but are observed to coexist in most habitats, despite the superior competitive ability of bacteria. The mechanisms that allow this coexistence are currently unknown, and this study will use laboratory investigations to explore them. This will be done by growing algae and bacteria together under defined conditions, identifying the organisms that coexist, and determining their properties that allow coexistence. Working hypotheses to be examined in these studies include (1) the possibility that lack of a sufficient supply of dissolved organic carbon, required by bacteria but not algae, limits the ability of bacteria to consume phosphorus, (2) the possibility that algae and bacteria specialize on chemically distinct forms of phosphorus, (3) the possibility that when phosphorus supply varies, algae are best able to store phosphorus acquired at elevated concentrations, while bacteria are best able to acquire phosphorus at low background concentrations, and (4) the possibility that protozoa eating bacteria, but not algae, limit the growth of bacteria, thus allowing algae to acquire phosphorus. Excessive algal growth is a common water quality problem, and such excessive growth is often related to the phosphorus supply that a body of water receives. Understanding the competitive balance between algae and bacteria in acquiring this phosphorus will help provide a scientific basis for management of water quality.

9418096格罗弗不同种类的生物为争夺生长所需的资源而竞争。从理论上讲，这种竞争可能会导致除最好的竞争者之外的所有物种灭绝。淡水生境中的藻类和细菌经常竞争溶解的磷，这是一种基本的营养物质，但据观察，尽管细菌具有优越的竞争能力，但它们在大多数生境中共存。允许这种共存的机制目前尚不清楚，这项研究将使用实验室调查来探索它们。这将通过在特定条件下一起培养藻类和细菌，识别共存的有机体，并确定它们允许共存的属性来实现。将在这些研究中检验的工作假设包括(1)细菌而不是藻类所需的足够的溶解有机碳的供应限制了细菌消耗磷的能力的可能性，(2)藻类和细菌专门研究化学上不同形式的磷的可能性，(3)当磷供应发生变化时，藻类最能储存在高浓度下获得的磷，而细菌最能在低本底浓度下获得磷，(4)原生动物食细菌，而不是藻类，限制了细菌的生长，从而使藻类能够获得磷。藻类过度生长是一个常见的水质问题，这种过度生长往往与水体获得的磷供应有关。了解藻类和细菌在获取磷的过程中的竞争平衡，有助于为水质管理提供科学依据。