Genome-scale model-guided microbial engineering for valorization of agricultural waste biomass to...

Increasing concerns on zero-waste and sustainability emphasize industrially feasible bioprocesses using renewable waste. Despite conventional physicochemical treatments, advanced microbial platforms converting agricultural waste into value-added biocompounds remain unexplored. Here, we report the development of platform E. coli strain capable of producing poly(3-hydroxybutyrate) [P(3HB)] from agricultural waste biomass. First, metabolically engineered E. coli strain capable of producing P(3HB) was constructed and tested its performance using five different agricultural lysates. Subsequently, the nutritional composition was analyzed to identify key components for P(3HB) production. Next, RNA-seq integrated genome-scale metabolic analysis were applied to predict potential engineering targets for enhanced P(3HB) production. The final engineered strain (ΔgltA ΔacnA phaCAB⁺) produced 71.95 wt% of P(3HB), a 78% increase over the wild type. Furthermore, 5.75 g/L P(3HB) at 75.60 wt% from 7.60 g/L biomass was successfully achieved by fed-batch fermentation. These findings confirm radish waste valorization and the feasibility of agricultural waste biomass for bioplastic production.