A Continuous Culturing Device for use in Bacteriophage Evolution

在地表水中，每一个海洋微生物大约有10个病毒颗粒，细菌细胞的病毒感染在驱动种群结构中起着重要作用，反过来，是全球碳生物地球化学的基本组成部分。绝大多数海洋细菌及其病毒极其微小和稀释。人们对其共同进化的结果知之甚少。例如，直到最近，人们还认为，超小型细菌的大小，如无处不在的Pelagibacter sp .，能够通过“隐性逃逸”避免病毒感染。然而，在2013年，这种想法被证明是错误的，因为发现了感染远洋杆菌的病毒，这种细菌在全球海洋中占主导地位。该项目将调查宿主和病毒的共同进化，以及它们的大小和海洋环境中的生命如何影响它们的生物和物理后果。该项目的目的是研究宿主/病毒大小和海洋中流体流动导致的复杂相遇模式的共同进化后果。为了实现这一目标，学生将比较Pelagibacter及其病毒的共同进化与一系列不同大小的宿主和病毒对的共同进化。共同进化适应将分别在普利茅斯海洋实验室的环境单细胞基因组学设施中使用单细胞基因组分析和原子力显微镜来观察基因型和表型变化（专注于细胞膜适应）。在第二步，共同进化实验将在一系列不同的流体环境中进行。特别是，细菌和病毒在海洋中相遇的不同场景将在实验室中通过精细控制区隔微流体环境来模拟。如果学生感兴趣，这种方法背后的理论考虑可以用于研究流体流动对协同进化的理论影响。虽然工作的重点是实验协同进化，但该项目可以包含不同数量的技术开发和理论工作。经过一段时间的初步培训后，学生将被鼓励与主管一起开发项目设计。

With approximately 10 viral particles for every marine microbe in surface water, viral infection of bacterial cells plays a significant role in driving population structure and, in turn, is a fundamental component of global carbon biogeochemistry. The vast majority of marine bacteria and their viruses are extremely small and dilute. The co-evolutionary consequences thereof are poorly understood. For example, it was thought until recently that the size of ultra-small bacteria such as the ubiquitous Pelagibacter spp. enabled avoidance of viral infection through 'cryptic escape'. Yet, in 2013, this idea was proved false by the discovery of viruses infecting Pelagibacter, which dominate global oceans.This project will investigate the coevolution of host and virus and how they are shaped by the biological and physical consequences of their sizes as well as by life in a marine environment.The aim of this project is to investigate the co-evolutionary consequences of host / virus size and complex encounter patterns due to fluid flow in the ocean. To achieve this goal, the student will compare co-evolution of Pelagibacter and its virus with co-evolution of a range of host and virus pairs with varying size. Co-evolutionary adaptations will be investigated using single-cell genomic analysis and atomic force microscopy to visualise genotypic and phenotypic changes (focusing on cell-membrane adaptations), respectively, within the environmental single cell genomics facility at Plymouth Marine Laboratory.In a second step, co-evolution experiments will be performed in a range of different fluidic environments. In particular, different scenarios of encounters of bacteria and virus in the ocean will be mimicked in the laboratory through the exquisite control of compartmentalised microfluidic environments. The theoretical considerations underlying this approach can be used to study the consequences of fluid flow on co-evolution theoretically if the student is interested.While the focus of the work will be on experimental co-evolution, the project can contain a varying amount of technology development and theory work. Following a period of initial training, the student will thus be encouraged to develop the project design together with the supervisors.