Levansucrase optimization using solid state fermentation and levan biological activities studies

Abstract

Bacillus subtilis NRC1aza produced levansucrase under solid state fermentation using starch as support. A sequential optimization strategy, based on statistical experimental designs is employed to enhance enzyme productivity. First, a 2-level Plackett-Burman design was applied for bioprocess parameters screen that significantly increase levansucrase production. Second optimization step was performed using fractional factorial design in order to optimize the amounts of highest positive variables that had significant effect on levansucrase productivity. Maximal enzyme productivity of 170 U/gds was achieved in presence of glucose, yeast extract, and pH 8. In vitro, experiments confirmed that LevCR and LevQT had an antitumor activity against different animal and human cancer cell lines by demonstrating inhibitory effects on growth of Ehrlich ascites carcinoma cell line, human MCF-7 breast and liver HepG2 cancer cell lines, in particular LevQT was found to be efficacious compared to anticancer drug, cisplatin. Result focused in LevCR as strong fibrinolytic agent.