Development of biosensor technology for the measurement and control of off-note flavours in the Scotch Whisky industry

该项目是与苏格兰威士忌研究所(SWRI)的合作项目。该项目的目的是研究开发基于生物传感器的技术来识别和量化威士忌中存在的化合物的潜力，这些化合物将被消费者视为非注意事项，目的是开发可用于生产环境的快速质量控制技术。由于风味是苏格兰威士忌消费者可接受性的主要驱动力，因此行业监测、控制和优化其产品的风味至关重要。目前，该行业采用两种方法来测量风味，化学分析(例如，GCMS)和由训练有素的人类鉴定员进行感官评估。分析方法无法考虑化合物混合物的影响，可能缺乏所需的灵敏度，而人类评估存在不可避免的变异性。该项目将探索模拟实际味道感知的生物测量，重点是开发特定的生物传感器来检测主要的异味味道，这些味道可以在橡木桶中随着威士忌的成熟而形成。要有用，生物传感器装置必须灵敏、特异，并在使用时快速反应，而不需要将样本转移到实验室。转录生物传感器依赖于遗传启动子元件对特定分子的反应。基于活细胞的传感器不能在实验室以外的环境中使用，但这可以通过使用无细胞转录-翻译(TX/TL)系统，甚至更简单的仅转录(TXO)系统来克服，这些系统简单、廉价，可以在几分钟内给出肉眼可见的反应(Millacura等人，2020)。这个项目旨在开发这种类型的生物传感器来检测四类化合物：‘霉变’(三氯苯甲醚，特别是2，4，6-三氯苯甲醚)；‘酸’(醋酸)；‘溶剂’(乙酸乙酯)；和‘酚类’(酚和甲酚)。这需要发现合适的响应性启动子，并将它们引入TX/TL和TXO系统进行评估。如果已知的启动子对所需的目标有反应，则可以合成这些启动子，并针对纯化合物进行测试，然后由SWRI提供样品。其次，各种细菌将被暴露在目标化学物质的蒸气中，以经验地确定哪些启动子被激活。有希望的启动子将通过定向进化得到进一步改进。同时，将开发一种适用于测试环境的改进的传感器格式。这样的平台在许多其他应用中也可能是有价值的。成功的候选人将能够与威士忌生产商联系，由SWRI提供行业联系和一个展示和讨论结果的论坛。此外，他们将加入IBioIC博士培训计划以及合成与系统生物学跨学科中心(SynthSys)的学生队伍，在那里他们将被鼓励充分利用现有的专业知识和世界级设施，获得相关实验技术和可转移技能的深入培训，以支持他们未来的职业发展

This project is a collaboration with the Scotch Whisky Research Institute (SWRI). The aim of the project is to investigate the potential of developing biosensor-based technology to identify and quantify compounds present in whiskies that would be perceived as off-notes by the consumer, with the aim of developing rapid quality control techniques that could be used in the production environment.Since flavour is the primary driver of consumer acceptability in Scotch Whisky, it is vital that the industry monitors, controls and optimises the flavour of their products. Currently the industry takes two approaches to the measurement of flavour, chemical analysis (eg, GCMS) and sensory evaluation by trained human assessors. Analytical methods fail to account for the effects of mixtures of compounds, and may lack the required sensitivity, whereas human assessment has an unavoidable level of variability.This project will explore biological measurements which mimic actual perception of flavour, focusing on the development of specific biosensors for the detection of the main off-note flavours that can develop as whisky matures in oak casks. To be useful, the biosensor device must be sensitive, specific, and give a rapid response at the point of use, without requiring samples to be transferred to a laboratory. Transcriptional biosensors rely on the response of genetic promoter elements to particular molecules. Sensors based on live cells can not be used outside a laboratory setting, but this can be overcome by the use of cell-free transcription-translation (TX/TL) systems, or even simpler transcription-only (TXO) systems, which are simple, cheap, and can give responses visible by eye within minutes (Millacura et al, 2020).This project aims to develop biosensors of this type to detect four classes of compounds: 'musty' (anisoles, especially 2,4,6-trichloroanisole); 'sour' (acetic acid); 'solvent' (ethyl acetate); and 'phenolic' (phenols and cresols). This requires discovery of suitably responsive promoters and introducing them into TX/TL and TXO systems for evaluation. Where known promoters exist which respond to the desired targets, these may be synthesised and tested against pure compounds and then samples supplied by SWRI. Secondly, various bacteria will be exposed to vapours of the target chemicals to empirically determine which promoters are activated. Promising promoters will be further improved through directed evolution. In parallel with this, an improved sensor format will be developed which is suitable for the testing environment. Such a platform could also be valuable in many other applications.The successful candidate will be able to liaise with whisky producers, with SWRI providing industry contacts and a forum to present and discuss results. Additionally they will join a cohort of students within the IBioIC PhD training programme, as well as the interdisciplinary Centre for Synthetic and Systems Biology (SynthSys), where they will be encouraged to make full use of the expertise and world-class facilities available, to gain in-depth training in relevant experimental techniques and transferable skills to support their future career developmen