Synthetically engineered microalgae for improved gut function and human health

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Microalgae are small microscope plants that have the ability to produce important nutritional components, including proteins, carbohydrates and lipids. They can even be used to sequester carbon dioxide and make useful products such as nutraceuticals, pharmaceuticals, biomaterials and biofuel. They usually are grown in water and can absorb nutrients providing cleaner waste water and reduce eutrophication. Making this vision for microalgae a reality has been the focus of many scientists and engineers since the 1970s. They have been declared a solution to the world's problems, being able to address nutrition shortages as the world's population grows to 9 billion people by 2050, reduce CO2 emissions as the world suffers from climate change and produce a sustainable economy as the world reduces its reliance on fossil fuels and the material by-products. To achieve this vision, however, there are hurdles associated with the scaling-up process from laboratory to what would be considered useful commercially. The main bottlenecks are on the ability to grow algae at scale, utilising inexpensive nutrients, and the dewatering process, or extracting the algae from the water (dewatering), and then extraction of useful compounds from the microalgae. Experiments at the University of Glasgow demonstrated growing microalgae on thin films as a way to overcome dewatering costs, financially and in terms of energy. Growing them in this way, allows them to grow as a biofilm. Little work has been done investigating this biofilm formation in this context but it was clear from this work that the yields were low on occasions. Having a reliable and high yield and understanding the impact of growth conditions (e.g. substrate material, temperature, pH, water activity) is important to progress and scale the applications). Recently, the world has seen incredible changes in being able to manipulate genomes of different organisms, a lot of this work has focussed on bacteria, but there is a growing interest in being able to manipulate microalgae to improve their characteristics e.g. growth rate or overexpress certain molecular compounds. Little work has been done on engineering microalgae to grow as biofilms, which is the focus of the current project. Thin film photo bioreactors will be built with sophisticated, yet simple, control systems to monitor biofilm growth, and use nutrients extracted from food-grade waste-streams. Their performance will be assessed with wild-type strains of microalgae, and then the ability to improve the microalgae yields and characteristics will be observed with engineered microalgae. Specifically, components that will be overexpressed as a way of developing and demonstrating these new methodologies will include Vitamin B12, which is an essential vitamin that cannot be produced in the body, Lutein (a carotenoid, found in the human eye in the macular and retina) and exopolysaccharides (EPS, which can help gut health). Once grown, samples will be analysed and compared using state of the art equipment, under the "omics" umbrella, allowing detailed assessment of proteins, carbohydrates and lipids. Samples will also be assessed for their impact on gut function using in-vitro models. Control systems will be developed and the data collected from each part of the process to develop new models, assessing life cycle analysis, techno-economic assessment and new machine learning codes to help understand the opportunities from this work.Ultimately the work will serve as the bases for a new area of research to impact society through improved nutrition development, and spring board into other areas to impact sustainability and climate change.