Engineering a robust and autonomous biological funneling for efficient valorization of lignin-related aromatics

Abstract

Abstract Lignin-related aromatics are promising renewable feedstocks, but their microbial conversion into useful compounds is fundamentally constrained by substrate toxicity and metabolic flux imbalance. Here, we report an autonomous microbial system in Corynebacterium glutamicum , which integrates evolutionary engineering with multiplexed dynamic control to overcome these constraints. This system features a robust, evolved chassis with reinforced cellular defenses and upgraded aromatic efflux machinery. We engineer a layered, multi-input regulatory network that enables real-time, substrate-responsive and precise control of metabolic pathways. This system achieves 99.89% conversion of diverse lignin-related aromatics to protocatechuic acid and subsequently achieves a titer of 53.40 g L⁻¹. This further supports high-titer production of value-added downstream chemicals, including cis,cis -muconic acid and β-ketoadipic acid with titers of 51.90 g L⁻¹ and 38.33 g L⁻¹, respectively. This work establishes a versatile and scalable paradigm for the autonomous bioprocessing of lignin feedstocks into sustainable value-added products.