Development of a biotechnology platform for enzymatic sulfation of industrial products based on polysaccharide sulfotransferases

Lead Research Organisation: University of Liverpool
Department Name: Biochemistry

Abstract

A wide range of household products as diverse as foodstuffs, cleaning materials and personal care products, rely on the ability to modify starting materials on an industrial scale to generate products with the desired properties. One key requirement in many cases is the introduction of charged groups, to bestow the desired characteristics such as the ability to gel, to bind other materials or to behave as detergents. This can often be achieved by the addition of charged groups and one key way to do this is to add a sulfate group. The problem is that this is done currently using toxic and environmentally damaging chemicals.

The global market for such household products is huge and growing, for example, for personal care products is $ 7.35 Bn with annual growth of 7%. Our industrial collaborator, Unilever, with whom we have a long and well-established working relationship, is a major global player, with around 50% of the market share.

Consumer sensitivity to environmental concerns, particularly with existing petroleum-based products and the use of harsh chemicals, arising from their resistance to biological degradation, the generation of greenhouse gases and other environmental issues during their production or disposal, has culminated in commercial pressure to develop sustainable alternatives.

The current method of achieving sulfation industrially, involving aggressive chemicals which show poor selectivity and are environmentally damaging, needs to be replaced with a one employing renewable resources without damaging the environment. Together with Unilever, we aim to develop methods by which sulfation can be achieved using enzymes, thereby avoiding these problems. The route we propose - engineering enzymes to carry out this modification - offers both better control of the process and, crucially, enables environmentally responsible production of biodegradable products and waste.

Until now, the application of enzymes to these areas has been hindered by the problems of readily detecting the modifications that have been made and, owing to the cost of some of the materials involved, also of developing a commercially feasible method of adding sulfate groups. Now, however, as a result the combination of preliminary work carried out by ourselves and Unilever, as well as other technological advances, both of these problems can be solved. This project will exploit these improved technologies, together with our established expertise in enzyme production to achieve two principal aims:

(i) to assemble the technology (termed the high throughput enzyme-engineering platform) with which to produce and optimise enzymes that will be suitable for application to a wide range of enzyme-driven processes of industrial relevance and,

(ii) to illustrate the use of this platform to select and optimise suitable enzymes, using a class of enzymes that can add sulfate groups to naturally-occurring and renewable starting materials such as complex sugars (polysaccharides) and lipids (glycolipids) from plants.

The potential for industrial application of these sulfated products will then be assessed by Unilever, a major global company with a developed sustainability agenda that, in the future, will enable delivery of clean, renewable products.

Technical Summary

Sulfation is one way to improve the properties of materials such as polysaccharides and lipids for many industrial applications, ranging from food products (e.g. gelling polysaccharides) to personal care products (e.g. surfactants). The global market for these products is huge and growing, e.g. for personal care is $ 7.35 Bn with 7% growth p.a. Our industrial collaborator, Unilever, with whom we have a well-established working relationship, is a global player with 50% market share.

The current method of sulfating polysaccharides and surfactants industrially involves aggressive chemicals (sulfur trioxide and sulfamic acid) which show poor selectivity and are environmentally damaging. Together with Unilever, we aim to develop enzymatic methods to achieve sulfation, offering better control of the process and the products generated, as well as, crucially, enabling environmentally responsible production of biodegradable materials and waste products.

The application of sulfating enzymes (sulfotransferases; STs) to these sugar-containing materials has been hindered by the problem of detecting sulfation (it has no readily detected absorption characteristics, e.g. in the UV region) and the expense of generating the sulfate donor, PAPS. These challenges have now been met by the combination of our high throughput screening method and the development of recyclable PAPS systems. This project will exploit these advances, together with our established expertise in enzyme manipulation and expression, to:

(i) assemble a generic enzyme-engineering HT platform, suitable for application to a wide range of enzyme-driven processes and,

(ii) to illustrate the use of the platform, using STs to modify polysaccharides and glycolipids, both examples of high-value renewable materials.

The potential for application of these sulfated products will be assessed by Unilever a global company with a developed sustainability agenda, aligning with the BBSRC's strategic aims.

Planned Impact

Impact Summary

Investment in basic research, alongside that designed to move discovery to a position where transition to Technology Readiness Level (TLR) 4, or beyond is feasible, underpins improvements in prosperity and societal benefit. The strategic plans of BBSRC highlight the importance of securing diverse impacts from funded research.

Our proposal exploits new tools and technology developed with previous funding from BBSRC and EC to evaluate the addition of a specific chemical group (sulfate), to biological molecules. Although biologically importanct, it had received little strategic funding but developments of high-throughput methods to measure enzymatic sulfation and interest from industry in sustainable routes to sulfation are changing this landscape. Our proposed platform builds on existing investment and will have substantial impact on the production and modification of enzymes to replace existing catalysts, as well as to access, new, sustainable & high value chemicals. This approach and the involvement of a major global player, Unilever, will have game-changing effects on the transition to sustainable and biodegradable chemicals and materials.

The early description (Year 1) of individual platform components and their exploitation for enzyme discovery and optimisation will be afforded by the initial cycle of STs through the platform, enabling IP positions to be defined. With Unilever (Year 1-2), we will then maximise visibility by publication in high-profile open access journals in chemical biology, biochemistry/biotechnology and through open access databases (Uniprot, Genebank). GeneMill will engage with the wider community, including Unilever and its extensive supply chain, to provide training in platform use. Many enzymes of biotechnological interest lack high-throughput activity screens, e.g., cyclases, and SB's expertise in Eu-based host-guest sensors will enable the scope of the platform to include many enzyme classes.

Conferences for scientists and the public (Years 1-2) provide the first route to general dissemination, while presenting at subject-specific conferences allows the power of our platform for analysis and development of STs and other enzyme classes to be targeted effectively. A global approach to enzyme modification and optimisation provides greater understanding and rapid transition to industrial relevance. All the research teams are active in conference support and delivery, across diverse audiences, including scientists (biochemistry, biotechnology, chemical biology & chemistry) and non-scientists (non-science undergraduates, schools & museums). These groups will be contacted during the project via distinct activities at UoL and at 'Pint Of Science', and Liverpool Museum open days, during which clear explanations of the role of sulfation, how well-known sulfated high value products are made currently and how our platform enables a transition to sustainable chemicals, will be provided through a portable display suitable for departmental, school, museum or national exhibitions.

All those involved will receive training in impact delivery as appropriate from BBSRC and the PIs. The applicants strongly advocate public-private partnerships to unlock commercial potential e.g. IBCarb awards (IB & EY), DF's long-term support from Allergan Inc. & SB's commercialisation of nucleotide luminescent sensors. By collaborating with groups such as 'Sense About Science', we will explain to the public how basic research on enzymes can transform the production of high value chemicals in well-known products and meet the social ambition of sustainability.

The PDRA will engage in related disciplines in this industry-facing project and develop their skills in high throughput techniques that underpin the discovery and improvement of enzymes as catalysts. Given the strong support and training available from the team, this provides for the PDRA's evolution into a scientific leader in a key area.

Publications

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Description Polysaccharide sulfation 
Organisation Unilever
Department Unilever UK R&D Centre Port Sunlight
Country United Kingdom 
Sector Private 
PI Contribution We conducted the NMR analysis of biomaterial.
Collaborator Contribution In-kind contribution to cover part of the research project.
Impact Publication
Start Year 2021