Harvesting the Photonic Properties of Self-Organising Bacteria Colonies

该项目的主要目标是研究和利用一种新型黄杆菌(IR1菌株)菌落的光子特性，这种细菌自组装成光子晶体。该菌株是一种直径约400纳米的杆状海洋细菌，以紧密的六角形格子集结在一起。由于可见光谱的一部分被这个组织强烈反射，菌落看起来像明亮的、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。我们尤其希望了解：(I)光散射如何与结构组织(周期性、规律性)相关，以便我们能够对它们进行光学筛选；(Ii)基因修饰如何改变光学性质并揭示着色的重要遗传途径；(Iii)如何在保持细菌群体光学性质的同时固定细菌群体。我们已经确定了通过生长条件和许多类型的外部刺激可逆和不可逆地改变活菌落组织(从而改变颜色)的广泛方法。学生将使用我们成熟的表征方法和知识来探索如何将这种细菌系统改造成可控的光子应用。这将涉及广泛的传统微生物学工具，从筛选生长条件到通过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.