Improved co-production of S-adenosylmethionine and glutathione using citrate as an auxiliary energy substrate

► Batch co-production of SAM and GSH was increased by sodium citrate addition. ► Sodium citrate improved intracellular ATP and the ratio of ATP/ADP. ► Sodium citrate acted as an auxiliary energy substrate for SAM and GSH overproduction. ► Key enzymes associated with SAM and GSH biosynthesis altered with citrate addition.