The ERA-CoBioTech project BESTER establishes clostridial bioprocesses for an optimized integrated production of a range of different butyl esters using lignocellulosic sugars as a sustainable feedstock for the commodity chemicals market. Efficient organic acid production processes will be developed, which can be linked to ABE fermentation processes as a source of BuOH. BESTER will thereby address in a coordinated way the two key handles for efficient production of the three acids, i.e. a) Systems biology driven strain engineering using Synthetic biology principles to establish new acid production in suitable clostridial chassis strains and mitigate key metabolic bottlenecks hampering high productivity, and b) smart process design and integration to prevent inhibitory effects of the acids produced and the BuOH added in efficient bioprocesses with continuous enzymatic ester product formation and recovery. Lignocellulosic feedstock hydrolysate will be used as the main feedstock in BESTER. The primary project deliverable will be a set of scalable, robust, and highly productive manufacturing processes for selected butyl esters.