Next-generation control strategy for biomanufacture

Abstract

The development of effective and reliable control strategies plays a critical role in the optimisation of all bio-based processes, especially with respect to their scaling-up and general transition towards industrial-scale manufacturing. The complexity of the reactions occurring and the sensitivity of the biological components involved place stringent demands on the availability of fine- tuning capabilities and responsiveness of bioprocess control systems. Nevertheless, the implementation of powerful control techniques is hindered by the lack of accurate measurements. In fact, it is fundamental to possess accurate metrics in order to monitor both insightful process parameters and outputs of the implemented control strategies. The collection of such data usually follows the compromise: high accuracy – long measurement time, as opposed to low accuracy – short measurement time. This project aims to build and validate an innovative monitoring platform, that will allow the implementation of advanced control techniques to a number of bioprocesses. This platform, called BioControl 1.0, consists in a Graphic User Interface (GUI) programmed in MATLAB language and it allows the user to collect and interpret data from a Proton Transfer Reaction Time of Flight Mass Spectrometer (PTR-ToF-MS). The PTR-ToF-MS will sample the headspace of a bioreactor, providing a real-time measurement of the compounds contained in the gaseous phase – in equilibrium with the subjacent liquid one, the concentration of whose solutes is the target of this measurement method. Despite the applicability of such setup to several processes, this study targets the production of linalool production, a terpene with the potential of being transformed into biofuel. Bacterial synthesis of linalool via E. coli has been studied through plasmid engineering: repeated DNA sequences over different areas of the plasmid have been selectively removed, enhancing production consistency (from 13% successfully transformed colonies to 100%) while attaining maximum average titres around 165mg/Loverlay in small-scale batches (i.e. 5mL). BioControl detection capability towards linalool has been tested on scaled-up E. coli fermentations carried out in 1L bioreactors (500mL of working volume), resulting in accurate tracking of linalool concentration profile in the liquid phase over a 30h operation time. Linalool titres as low as 100ppb-vol have been successfully detected, while scaled fermentation led to the accumulation of a maximum of 190mg/ Loverlay. Feasibility of linalool production control through optogenetics has been tested through MATLAB and Simulink simulations, indicating that stable control is viable.

Date of Award	1 Aug 2021
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Nigel Scrutton (Supervisor), Sam Hay (Supervisor) & Eriko Takano (Supervisor)