Out-of-specification tomato paste, a by-product from the tomato processing industry, was used as the sole substrate for cultivation of the bacterium Enterobacter A47 and production of FucoPol, a value-added fucose-rich extracellular polysaccharide. Among the different tested fed-batch strategies, pH-stat, DO-stat and continuous substrate feeding, the highest production (8.77ï¿½gï¿½L−1) and overall volumetric productivity (2.92ï¿½gï¿½L−1ï¿½d−1) were obtained with continuous substrate feeding at a constant flow rate of 11ï¿½gï¿½h−1. The polymer produced had the typical FucoPol composition (37ï¿½mol% fucose, 27ï¿½mol% galactose, 23ï¿½mol% glucose and 12ï¿½mol% glucuronic acid, with an acyl groups content of 13ï¿½wt%). The average molecular weight was 4.4ï¿½× 106ï¿½Da and the polydispersity index was 1.2. This study demonstrated that out-of-specification tomato paste is a suitable low-cost substrate for the production of FucoPol, thus providing a route for the valorization of this by-product into a high-value microbial product.
- Continuous feeding
- DO-stat mode
- Extracellular polysaccharide (EPS)
- pH-stat mode
- Tomato paste