CHWWEPS

CHWWEPS project aims at developing a valorization route for wastes/effluents difficult to valorize, from industrial and municipal sources, to produce added-value polymers such as Alginate. Wastes/effluents containing heterogeneous mixtures of macromolecular carbohydrate substrates (such as cellulose or starch) together with other carbon substrates (proteins, lipids) as well as other organic and inorganic contaminants will be first hydrolyzed to produce hydrolysates containing a significant fraction of monomeric sugars. The obtained hydrolysates will be further used as carbon source for the microbial production of exopolyssaccharide polymers (EPS) of commercial interest. The strain on fossil resources in our carbon based economy puts an increasing pressure on agricultural and biomass resources for both food and non-food applications (biofuels, bioenergy, chemicals and polymers). On the other hand, increasing human activity has led to production of significant amounts of wastes. A truly sustainable carbon based economy will require a zero waste discharge, that is, that all the intrinsic organic and inorganic value present in waste/effluent streams be recovered prior to rejection after treatment back into the natural environment. Sustainable production processes based on renewable biobased feedstocks need to fully use this potential recyclability of the organic carbon derived from biological sources. In a circular biobased economy, we cannot simply replace fossil-based carbon sources by biobased carbon sources while keeping the same linear production processes (substrate to product to waste to CO2), but instead need to develop business models for our production chain in which carbon can be used in consecutive cycles before being finally oxidized to CO2 or converted to methane (energy). A key aspect of the project is the demonstration of this multi-cyclical approach to biogenic carbon use. A large number of bacterial exopolyssaccharides (such as Alginate) have been identified to date, but only a few are used in industrial processes, all of which produced using pure microbial cultures from high cost carbon substrates. The rheological properties of such bacterial EPS are similar to those of exopolyssaccharides extracted from algae, which are currently used as thickeners and flocculants. EPS can thus be used to promote dehydration and control process rheology. Wastewater (WW) treatment processes require coagulation and flocculation agents to remove suspended mater (clarification). Chemical coagulatants and flocculants are generally used (FeCl3 or polymeric materials, such as PAM). Veolia Water has a growing interest in the use biopolymers both in drinking water and in WW treatment processes as a means of reducing the dependence of its processes on chemicals, in order to improve their environmental sustainability. Furthermore, if such biopolymers can be produced from WWT by-products (thus closing the value chain), this would also reduce treatment cost dependence on external supply of reagents. Therefore, a significant in-house interest for the product targeted by CHWWEPS project is also at the center of this project (improve industrial competitiveness). CHWWEPS aims to directly reuse the EPS produced targeting applications in WWT processes, thus making this project a true example of a circular economy business model (in which supplier and end-user are the same). CHWWEPS project focuses on the use of waste-based feedstocks aiming to surpass those challenges (heterogeneity of matrices, complexity of feedstock, diluted streams) which make them difficult to valorize by an innovative approach which consists in: Rather than using specific bacterial cultures (as in pure culture processes) trying to condition the substrate in order to fit to the organism, CHWWEPS aims at engineering open microbial consortiums by the imposition of appropriate selection pressures targeting function specialization, in this case EPS synthesis.