Inulinase synthesis from a mesophilic culture in submerged cultivation

A newly isolated mesophilic bacterial strain from dahlia rhizosphere, ident ified as Staphylococcus sp, and designated as RRL-M-5, was evaluated for in ulinase synthesis in submerged cultivation using different carbon sources i ndividually or in combination with inulin as substrate. Inulin appeared as the most favorable substrate at a 0.5-1.0% concentration. Media pH influenc ed the enzyme synthesis by the bacterial strain, which showed an optimum pH at 7.0-7.5. Supplementation of fermentation medium with external nitrogen (organic and inorganic) showed a mixed impact on bacterial activity of enzy me synthesis. The addition of soybean meal and corn steep solid resulted in about an 11% increase in enzyme titers. Among inorganic nitrogen sources, ammonium sulfate was found to be the most suitable. Maximum enzyme activiti es (446 U/L) were obtained when fermentation was carried out at 30 degrees C for 24 h with a medium containing 0.5% inulin as a sole carbon source and 0.5% soybean meal as the nitrogen source. Bacterial inulinase could be a g ood source for the hydrolysis of inulin for the production of D-fructose.