Effect of Corn Steep Liquor on 2-Keto-L-Gulonic Acid in Two-Step VC Fermentation

By adding different amounts of corn steep liquor(CSL) into medium,the effects of CSL on the precursor of VC,2-keto-L-gulonic acid(2-KGA),production in two-step fermentation process of vitamin C by Gluconobacter oxydans(Go) were studied,the effects of 12 main amino acids,the component in CSL on the 2-KGA production were also studied.The results showed that the yield of 2-KGA was as high as 26.84 mg/mL when sterile and filtered CSL was added 2.5 g in every 100 mL culture medium,and as much as 9.74 time of live cells of Go more than that without adding CSL.Immoderate amount of CSL constricted Go to produce 2-KGA.Neither individual amino acid nor mixture of all amino acids had the effect on the fermentation culture of Go to produce 2-KGA and thallus growth.