Intensification of media components can effectively improve biochemical production by reinforcing the metabolic capacity of engineered strains. Here, we present a citrate-enabled medium intensification strategy for sustainable l-theanine biomanufacturing in Corynebacterium glutamicum. Recombinant strains expressing heterologous theanine synthases were constructed using a strain expressing l-glutamate-l-cysteine ligase from Escherichia coli (THE-6) to achieve high theanine production. To establis