Abstract:

E. coli BL21(DE3) containing recombinant plasmid pExSecI buckwheat trypsin inhibitor (BTI) was constructed bygene cloning, and was cultured in a 100 L fermentor for large-scale fermentation. The fermentation products were purified byheat treatment and ion exchange chromatography. The purity of recombinant BTI obtained was greater than 95% after a series ofoptimization steps. Then fruit flies were fed with a medium containing different concentrations of rBTI (0, 20, 50 μg/mL). Themaximum lifespan, average lifespan and lethal dose-50 time were tested, respectively. The effect of the purified rBTI on he fruitfly’s lifespan was studied. The results showed that rBTI significantly extended the lifespan of fruit fly in a dose-dependent waywithin the range of experimental doses. At the same time, the activities of superoxide dismutase (SOD) and catalase (CAT) werefound to be significantly increased in the fruit flies of the experimental group. The preliminary studies indicate that the anti-agingeffect of rBTI on fruit flies may be achieved by increasing its anti-oxidative stress ability.

Key words: buckwheat trypsin inhibitor, Drosophila melanogaster, lifespan, antioxidation