Harvesting the Photonic Properties of Self-Organising Bacteria Colonies

该项目的总体目标是研究和利用一种新型黄杆菌（菌株IR1）菌落的光子特性，这种菌落可以自组装成光子晶体。该菌株是一种棒状的海洋细菌，直径约为400nm，聚集在一个紧密的六边形晶格的菌落中。由于可见光谱的一部分被这个组织强烈反射，所以这些群落呈现出明亮的、闪闪发光的绿色。这种效应可以用光子晶体理论来描述，不涉及色素沉着。我们特别希望了解：(i)光散射与结构组织（周期性，规律性）的关系，以便我们可以用光学方法屏蔽它们；（ii）基因修饰如何改变光学特性并揭示重要的遗传着色途径；（iii）如何在保持菌落光学特性的同时固定菌落。我们已经确定了通过生长条件和许多类型的外部刺激来可逆和不可逆地改变活菌落组织（因此颜色）的广泛方法。该学生将利用我们完善的表征方法和知识来探索如何将这种细菌系统修改为受控光子应用。这将涉及广泛的传统微生物学工具，从生长条件筛选到通过CRISPR进行DNA遗传学。

The overarching aim of the project is to investigate and utilise the photonic properties of colonies of a novel type of Flavobacterium (strain IR1), which self-assembles into photonic crystals. The strain is a rod-shaped marine bacterium with a diameter of roughly 400nm, that packs in colonies with a tight hexagonal lattice. The colonies appear bright, sparkling green since a part of the visible spectrum is strongly reflected by this organisation. The effect can be described by photonic crystal theory and does not involve pigmentation. In particular we wish to understand:(i) how light scattering relates to the structural organisation (periodicity, regularity) such that we can screen them optically;(ii) how genetic modifications change the optical properties and reveal the important genetic pathways for colouration;(iii) how to fixate the bacterial colonies while retaining their optical properties.We have identified a wide range of methods to reversibly and irreversibly change organisation (and hence colour) of the living colonies through growth conditions and many types of external stimuli. The studentship will use our well-established characterisation methods and knowledge to explore how this bacterial system can be modified towards controlled photonic applications. This will involve a wide range of traditional microbiology tools ranging from screening of growth conditions to DNA genetics via CRISPR.