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

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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.