The scale of the biological systems we can engineer is limited by the burden that host cells can bear. Division-of-labour can spread that burden across a community of cells but competitive exclusion inevitably leads to the removal of less fit community members over time. Here, we leverage amensalism and competitive exclusion to stabilise multi-species communities by engineering a strain of Escherichia coli which secretes a toxin in response to competition. We show mathematically and experimentally that such a system can produce stable populations with a composition that is tunable by easily controllable parameters. This is the first system to use competitive exclusion to create a stable two-species consortia and the first to only require the engineering of a single strain.

中文翻译：

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微生物菌群的单株控制

我们可以设计的生物系统的规模受到宿主细胞可以承受的负担的限制。分工可以将这种负担分散到整个社区中，但是竞争性排斥不可避免地导致随着时间的流逝，越来越不适合的社区成员被撤职。在这里，我们利用闭经疗法和竞争性排斥作用，通过设计大肠杆菌菌株来稳定多物种社区，该菌株可响应竞争而分泌毒素。我们在数学和实验上表明，这样的系统可以产生稳定的种群，其组成可以通过容易控制的参数进行调整。这是第一个使用竞争排斥来建立稳定的两物种联盟的系统，也是第一个只需要对单个菌株进行工程改造的系统。