Ordinary Students Keto Gulonic Acid Bacteria Sorbitol Dehydrogenase

In the two-step fermentation of vitamin C, the first step is the conversion of D-sorbitol into L-sorbose by Gluconobacter sp., and the second step is the conversion of L-sorbose into 2-Keto-L-gulonic acid (KGA) by ketogulonigenum vulgare with its companion strain. The companion strain could spur ketogulonigenum vulgare to grow and produce 2-Keto-L-gulonic acid (KGA).One fast growing Ketogulonigenium-like strains which can convert sorbose to KGA was obtained. With 16s rDNA analysis.This strain was identified as a fusion cell of Ketoguionigenium and Acinetobacter. Using the shuttle lasmid pWH1266,pWH1266-sdh was constructed and transferred into Acinetobacter to construct SDH expression system.Through the result of GST pull-down method and the negative effect of the growing of E.coli when SDH and cytochrome C are expressed together in it, it suggests that there are some sort of interaction between SDH and cytochrome CWe analyzed the effect of basees, folic acid and dihydrofolic acid on the growth of ketogulonigenum vulgare. We try to purify and identify the substance that spurs ketogulonigenum vulgare to grow from the companion stain. The substance may be a kind of protein because it is sensitive to temperature.