Bio-based production of cis,cis-muconic acid as platform for a sustainable polymers production

Production of the high industrial value cis,cis-muconic acid (ccMA) from renewable biomasses is of main interest especially when biological (green) processes are used. We recently generated a E. coli strain expressing five recombinant enzymes to convert vanillin (VA, from lignin) into ccMA. Here, we optimized a growing cell approach in bioreactor for the ccMA production. The medium composition, fermentation conditions, and VA addition were tuned: pulse-feeding VA at 1 mmol/h allowed to reach 5.2 g/L of ccMA in 48 h (0.86 g ccMA/g VA), with a productivity 4-fold higher compared to the resting cells approach, thus resulting in significantly lower E-factor and Process Mass Intensity green metric parameters. The recovered ccMA has been used as building block to produce a fully bioderived polymer with rubber-like properties. The sustainable optimized bioprocess can be considered an integrated approach to develop a platform for bio-based polymers production from renewable feedstocks.