3D-Printed Platforms to Study and Utilise the Photoelectrochemistry of Photosynthetic Biofilms

这项研究将在剑桥大学进行，目的是为研究和利用生物膜提供3D打印平台。微生物在表面形成生物膜的倾向在不同的环境中可能具有截然不同的含义。例如，根据美国国立卫生研究院的数据，微生物生物膜是医疗行业的一个大问题，因为它们对抗生素具有高度抗药性，同时会导致高达80%的感染。另一方面，有一个很大的社区正在利用生物膜的新陈代谢能力来修复废水，进行化学合成，并以廉价和可再生的方式发电。例如，包括蓝藻和藻类在内的光合作用微生物被招募来在导电基材上形成生物膜，以便在光照射期间向基材注入电荷，就像太阳能电池一样，这就是所谓的生物光伏。根除和开发微生物生物膜的单独努力目前都受到生物膜生物学复杂领域内知识差距的阻碍，在这一领域，支配生物膜生理学的界面生物膜与材料的相互作用还没有得到很好的了解。我们希望开发一个平台，在其中可以精确控制不同材料的表面形态，以研究和控制支架可以容纳的细胞数量。这将使用3D打印来完成，3D打印是一种在广泛应用中使用的强大的原型工具。作为一个起点，这项研究将集中在使用3D打印来优化蓝藻负载到导电支架中。负载的改善有望提高目前效率很低的生物光伏的太阳能发电转换效率。这个想法是使用3D打印来建立一个导电3D支架的库，这些支架的尺寸、形态特征、粗糙度和材料都不同，并对这些支架进行筛选，以获得高电池负载、生物膜形成，并在光照射下对它们进行测试，以测量太阳能对电荷的输出。该项目的一个重要平行目标是了解在光照射期间引起生物体和材料之间能量/电荷交换的潜在机制。目前尚不清楚这种交换是由于光合作用生物的自我保护机制，还是一种细胞间的交流方式，或者在多大程度上对生物膜的生理有害或有益。为了回答这些问题，将采用先进的成像和光谱技术来探索生物膜中常见细胞成分在黑暗和光明周期中的分布和化学。当项目的两个部分结合在一起时，可以设计出更全面的策略，以促进生物膜和导电支架之间的有效交换-通过细胞的生物工程和/或通过改变支架的结构/组成。这项研究最重要的成果是，新平台将开启生物膜在大量应用和研究领域的研究和利用。这项研究中开发的3D打印和成像策略可以用于改善当前和即将到来的生物膜生物技术和反应堆中生物膜与材料的相互作用。同样，它们也可以用于生物医学研究，例如，筛选抗生物膜药物，研究生物膜耐药性，以及研究微生物系统(如哺乳动物细胞)以外的大世界中的问题。该项目的一个更直接的结果将是为生物光伏提供有价值的经验教训和基准系统，这将有利于可再生能源研究。我们还将更多地揭开蓝藻令人着迷的光生物学，它们在地球生态中扮演着不可或缺的角色。

The aim of this research, which is to be carried out at the University of Cambridge, is to 3D-print platforms for studying and utilising biofilms. The propensity for microorganisms to form biofilms on surfaces can have profoundly contrasting implications in different contexts. For example, microbial biofilms are a large problem in the medical industry since they can be highly resistant to antibiotics whilst at the same time causing up to 80% of infections, according to the US National Institutes of Health. On the other hand, there is a large community who are harnessing the metabolic power of biofilms to remediate waste water, carry out chemical synthesis, and generate electricity in an inexpensive and renewable manner. For example, photosynthetic microorganisms, including cyanobacteria and algae, have been recruited to form biofilms on conductive substrates so that it would injects charges into the substrate during light irradiation, much like solar cells, in what is known as bio-photovoltaics. Both separate efforts to eradicate and exploit microbial biofilms are currently hindered by knowledge gaps within the complex field of biofilm biology, where the interfacial biofilm-material interactions that govern biofilm physiology are not well understood. We want to develop a platform in which the surface morphology of different materials can be precisely controlled to study and control the number of cells the scaffold can accommodate. This will be done using of 3D-printing, a powerful prototyping tool used in a wide range of applications. As a starting point, this research will focus on using 3D-printing to optimise cyanobacterial loading into a conductive scaffold. The improvement in loading is expected to improve the solar-to-power conversion efficiency of bio-photovoltaics, which is currently very inefficient. The idea is to use 3D-printing to build a library of conductive 3D scaffolds varying in dimensions, morphological features, roughness, and materials, and screen these for high cell loading, biofilm formation, and test them under light irradiation to measure solar-to-charge output. An important parallel aim of this project is to understand the underlying mechanisms that give rise to the exchange of energy/charges between the organisms and the material during light irradiation. Currently, it is not known whether this exchange is due to a self-protective mechanism by photosynthetic organisms, a mode of cell-cell communication, or to what extent it is detrimental or beneficial to the physiology of the biofilm. To answer these questions, advanced imaging and spectroscopic techniques will be adapted to probe the distribution and chemistry of common cellular components within the biofilm during dark and light cycles. When the two parts of the project are married up, more wholistic strategies to facilitate efficient exchange between the biofilm and the conductive scaffold can be designed - either through bioengineering of the cells and/or through altering the structure/composition of the scaffold. The most important outcome of this research is that the new platforms will open up the study and ultilisation of biofilms in a large number of applications and research fields. The 3D-printing and imaging strategies developed in this study can be adapted to improve biofilm-materials interactions in current and upcoming biofilm biotechnologies and reactors. Similarly, they can also be adapted for biomedical research to, for example, screen anti-biofilm drugs, study biofilm resistance, and study problems in the large world beyond microbial systems (such as mammalian cells). A more direct outcome of this project would be the generation of valuable lessons and benchmark systems for bio-photovoltaics, which would benefit renewable energy research. We would also unravel a little more the fascinating photobiology of cyanobacteria, which play indispensable roles in the Earth's ecology.