The Research Of Preparing L-Ascorbic Acid 2-Glucoside By Biological Transformation

Spinosad is derived from the fermentation product of a naturally occurring soil bacterium, Saccharopolyspora spinosad. It has a low acute oral and favorable environmental toxicity profile. To get the rapid screening pattern for Spinosad overproducing strain, the study that we have done were as follows:1. A quantitative analytical method was established for spinosyn by HPLC, using methanol: acetonitrile =2:1, velocity of flow: 1ml/min.2. The original strain were mutagenesised by UV DES 60Co and separated with 2 -DOG, the production of mutants were enhanced to 5.5 times of the original one.3. After excerpted the optima formula of fermentation medium, the optimal medium and cultural conditions were ascertained. The optimal medium was composed of glucose 6.0%, cottonseed flour 1.0%, yeast 0.2%; K2HPO4 0.02%, NaCl 0.02%, CaCO3 0.5%; And the optimal cultural conditions involved: shaking-flask experiments were done in 250-mL flasks containing 50mL medium with 5% inoculation quantity orbital shaking at 240 r/min. On the optimal fermentation condition the productivity of reached 142.73 mg/L, which was 17.54% higher than that of the original fermentation condition.4. High yield strain and low yield strain were tested and showed the biological characteristics diversity: the color of hydrolyzed grease in plate and determining the dissociated acid of fermentation fluid straightly relate to the producing of spinosyn, then establishment of the rapid screening pattern for spinosyn overproducing strain5. The fermentation curve of spinosyn high-producing strain AS-216 was studied in this dissertation.