Cellulose synthase complex configuration effects in microalgal cellulose

Project background (identification of the problem and its importance and relevance to sustainability)

Due to the current global food trade, plastic packaging has become essential in modern infrastructure. However, plastic, particularly single use, is causing negative environmental impacts. After use, only 14% of plastic is collected for recycling, with 32% being released into the environment. Plastic cannot be degraded by biotic factors and instead breaks down slowly to form microplastics that accumulate in the environment causing damage to humans and other organisms. One answer to this crisis is to replace conventional plastic materials with bioplastics. Bioplastics are plastic made from renewable resources, such as terrestrial crops, agricultural waste, or fast-growing microorganisms. Cellulose is the most abundant biopolymer in nature and is synthesised by many different organisms. Regenerated cellulose films could be ideal for food packaging due to their good barrier functionality, mechanical properties, biodegradability, and renewability. However, there are concerns about where a large amount of cellulose could be sourced sustainably without taking up space for growing food crops or causing deforestation. There are also some attributes of current cellulose sources which will need to be improved for use in a wide variety of packaging materials.
Many cellulose sources have been explored, but micro-algae is an under-researched area of particular interest due to its many advantages to other forms of cellulosic feedstock, including differentiation in cellulose structure.

Proposed solution and methodology

To utilise cellulose for food packaging, it is possible to create regenerated cellulose films. The process occurs by extracting the cellulose from the host species then breaking the bonds between the cellulose polymers. The cellulose polymers can then be reformed into a film by a coagulation medium which allows the cellulose polymers to bond, forming a film.
Micro-algae are species with different cellulose structures that may provide unique properties to the extracted cellulose. The structure in which the cellulose is formed depends on the position of the cellulose synthase complexes (Terminal Complexes). In higher plants, these are arranged in a hexagonal structure called a rosette structure. In microalgae, they can also be arranged as single rows, multiple rows, or diagonal rows. This difference in structure could impart different physicochemical properties, which would help create bioplastics for varying applications or combine for multiple purposes. Research into algal cellulose and its creation into algal films could therefore provide multiple benefits and help solve the current plastic crisis. The first phase of experimentation will be to use the model algae Chlorella vulgaris to develop a successful extraction and film formation process that allows for advantageous structural breakdown necessary for film formation whilst retaining some of the original cellulose structure. The second phase will be using diverse algal sources that present the different cellulose synthase complexes and compare the structure and the properties of the films. The final stage will be to optimise both the extraction process, to limit environmental impact and the properties of the film using algal species. This information can then be used for scaling up the production for use in the real-world practice setting.

This CDT will deliver impact aligned to the following agendas:

People
A2P will provide over 60 PhD graduates with the skill sets required to deliver innovative sustainable products and processes into the UK chemicals manufacturing industry. A2P will inspire and develop leaders who will:
- understand the needs of industrial end-users;
- embed sustainability across a range of sectors; and
- catalyse the transition to a more productive and resilient UK economy.

Economy
A2P will promote a step change towards a circular economy that embraces resilience and efficiency in terms of atoms and energy. The benefits of adopting more sustainable design principles and smarter production are clear. For example, the global production of active pharmaceutical ingredients (APIs) has been estimated at 65,000-100,000 tonnes per annum. The scale of associated waste is > 10 million tonnes per annum with a disposal cost of more than £15 billion. Consequently, even a modest efficiency increase by applying new, more sustainable chemical processes would deliver substantial economic savings and environmental wins. A2P will seek and deliver systematic gains across all sectors of the chemicals manufacturing industry. Our goals of providing cross-scale training in chemical sciences with economic and life- cycle awareness will drive uptake of sustainable best practice in UK industry, leading to improved economic competitiveness.

Knowledge
This CDT will deliver significant new knowledge in the development of more sustainable processes and products. It will integrate the philosophy of sustainability with catalysis, synthetic methodology, process engineering, and scale-up. Critical concepts such as energy/resource efficiency, life cycle analysis, recycling, and sustainability metrics will become seamlessly joined to what is considered a 'normal' approach to new molecular products. This knowledge and experience will be shared through publications, conferences and other engagement activities. A2P partners will provide efficient routes to market ensuring the efficient translation and transferal of new technologies is realised, ensuring impact is achieved.

Society
The chemistry-using industries manufacture a rich portfolio of products that are critical in maintaining a high quality of life in the UK. A2P will provide highly trained people and new knowledge to develop smarter, better products, whilst increasing the efficiency and sustainability of chemicals manufacture.
To amplify the impacts of our CDT, effective public engagement and technology transfer will become crucially important. As a general comment, 'sustainability' styled research is often regarded in a positive light by society, however, the science that underpins its effective implementation is often poorly appreciated. The University of Nottingham has developed an effective communication portfolio (with dedicated outreach staff) to tackle this issue. In addition to more traditional routes of scientific communication and dissemination, A2P will develop a portfolio of engagement and outreach activities including blogs, webpages, public outreach events, and contribution of material to our award-winning YouTube channel, www.periodicvideos.com.

A2P will build on our successful Sustainable Chemicals and Processes Industry Forum (SCIF), which will provide entry to networks with a wide range of chemical science end-users (spanning multinationals through to speciality SMEs), policy makers and regulators. We will share new scientific developments and best practice with leaders in these areas, to help realise the full impact of our CDT. Annual showcase events will provide a forum where knowledge may be disseminated to partners, we will broaden these events to include participants from thematically linked CDTs from across the UK, we will build on our track record of delivering hi-impact inter-CDT events with complementary centres hosted by the Universities of Bath and Bristol.