ABSTRACT
Objective To optimize extraction process of walnut quinone from Juglans green peel. Methods On the basis of single factor tests, taking material-liquid ratio, extracting temperature and ethanol concentration as independent variables, yield of walnut quinone in response to as a value, according to Box-Behnken experiment design principle, extraction process of walnut quinone from Juglans green peel was optimized by response surface analysis. Results The optimum extraction process of walnut quinone was: 14.30 times the amount of 89.81% ethanol;30.28 ℃ constant temperature. The extracting amount of walnut quinone was 2.034 mg/g, which was close to the experimental results of 1.957 mg/g. Conclusion The optimized extraction process is reasonable and feasible, which can provide reference for the extraction of walnut quinone from Juglans green peel.
ABSTRACT
Candida shehatae xyl1 gene and Pichia stipitis xyl2 gene were amplified by PCR and the xyl1 and xyl2 were both placed under the promoter GAL of vector pYES2 to produce the recombinant expression vector pYES2-P12. Subsequently the pYES2-P12 vector was transformed into S. cerevisiae YS58 by LiAc to produce the recombinant yeast YSS8-12. It was indicate that the recombinant yeast YSS8-12 could converse xylose to ethanol with the xylose consumption rate of 81. 3%.