Enhanced co-production of S-adenosylmethionine and glutathione by an ATP-oriented amino acid addition strategy

► Both methionine and cysteine are favor to SAM and GSH biosynthesis by C. utilis. ► Excessive ATP re-accumulated at 21 h during batch co-production of SAM and GSH. ► ATP-oriented cysteine addition strategy is better than the traditional methods. ► A two-stage ATP-oriented strategy improved SAM and GSH coproduction by 124.6%. ► The reliability of the strategy was verified by kinetic and metabolic flux analyses.