https://www.selleckchem.com/pr....oducts/ch5183284-deb
S-adenosyl-l-methionine (SAM) is a highly valued chemical that can be used as a dietary supplement and has been used to treat depression, osteoarthritis, and liver problems as well. We adopted systems metabolic engineering strategies to improve SAM production in a high-producing strain (GS115/DS56). First, the cystathionine β-synthase gene CYS4 was downregulated using a weak promoter PG12 to reduce the removal of homocysteine from SAM cycle, thus leading to a 48.8% increase in the SAM titer (1.68 g/L) from the strain G12-CB