A Complex Community in a Simple Habitat: An Experimental Study with Bacteria and Phage
A Complex Community in a Simple Habitat: An Experimental Study with Bacteria and Phage
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简单栖息地中的复杂群落：细菌和噬菌体的实验研究
DOI：
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发表时间：
1977
期刊：
影响因子：
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通讯作者：
F. M. Stewart
中科院分区：
文献类型：
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作者：
L. Chao;B. Levin;F. M. Stewart
连续培养的细菌种群，特别是大肠杆菌及其毒力病毒T7，已被研究作为一个简单的栖息地捕食者-猎物的模型。这些生物体在以下情况下维持明显稳定的共存状态：（1）噬菌体限制的情况，其中所有细菌对共存病毒敏感，并且唯一的潜在限制性碳源葡萄糖过量存在;和（2）资源限制的情况，其中大多数细菌对这些噬菌体具有抗性，并且其中几乎没有游离葡萄糖。这些相互作用的人口的组成进行了详细的研究和证据表明，这个简单的实验文化系统可以支持相对复杂的社区。在捕食者有限的情况下，可以维持两个营养水平的两个种群;野生型细菌和噬菌体菌株，表示为B 0和T70，对T70有抗性的突变细菌克隆表示为B1，宿主范围突变噬菌体T71能够在B 0和B1上生长。在资源有限的情况下，三个种群的细菌和两个种群的噬菌体可以共存。包括上述克隆和第三种细菌菌株B2，其对T70和T71都有抗性。在无噬菌体竞争中，野生型B 0细菌克隆相对于B1和B2具有显著优势，而在B1和B2之间没有检测到差异。当竞争B 0宿主时，野生型T70噬菌体克隆比T71具有显著优势。适合这些意见的一些以前开发的理论资源有限的增长，竞争和捕食进行了讨论，并提出了一种机制来解释这些社区的持久性。后者假设它们的稳定性可以完全归因于内在因素，即，在这种连续的养殖栖息地中，生物体的种群增长和相互作用特性。
Continuous culture populations of the bacterium especially coli and its virulent virus T7 have been studied as a model of a predator—prey in a simple habitat. These organisms maintain apparently stable states of coexistence in: (1) a phage—limited situation where all of the bacteria are sensitive to the coexisting virus and the sole, and potentially limiting carbon source, glucose, is present in excess; and (2) a resource—limited situation where the majority of the bacteria are resistant to these phage and in which there is little free glucose. The composition of these interacting populations is examined in detail and evidence indicating that this simple experimental culture system can support relatively complex communities is presented. In the predator—limited situation, two populations at each of two trophic levels can be maintained; the wild—type bacterial and phage strains, denoted B0 and T70, a mutant bacterial clone which is resistant to T70, denote B1 and a host range mutant phage, T71 which is capable of growth on both B0 and B1. In the resource—limited situation, three populations of bacteria and two populations of phage can coexist. The include the above described clones and a third bacterial strain, B2, which is resistant to both T70 and T71. In phage—free competition, the wild—type B0 bacterial clone has a marked advantage relative to both B1 and B2 while no difference is detected between B1 and B2. When competing for a B0 host, the wild—type T70 phage clone has a marked advantage over T71. The fit of these observations to some previously developed theory of resource—limited growth, competition and predation is discussed and a mechanism to account for the persistence of these communities is presented. The latter assumes that their stability can be attributed solely to intrinsic factors, i.e., the population growth and interaction properties of the organisms in this continuous culture habitat.