The prebiotic influence of inulin on growth rate and antibiotic sensitivity of lactobacillus cassei

Abstract

This research study is focused on the prebiotic effect of inulin on the antibiotic sensitivity of Lactobacillus casei and on the determination of functionality of specific growth rate (μ) of the probiotic bacteria on the concentrations of lactose (CL = 10-30 g/l) and inulin (CI = 0.164-0.625 g/l) along with the optimization of growth condition through Response Surface Methodology (RSM). The sensitivity of Lactobacillus casei towards norfloxacin was determined using well diffusion method. Using the initial values of μ (h-1) of Lactobacillus casei at different values of CL (g/l) and CI (g/l), the functionality of μ on the concentrations of the carbon sources have been derived, and the optimum condition has been identified. Although Lactobacillus casei is sensitive to norfloxacin, resistance is developed in the presence of inulin. Quadratic model equation μ = 0.83+0.054*CL-0.035*CI-0.049*CL*CI-0.29*CL2-0.33*CI2 is valid and the optimum value of specific growth rate is 0.8285 h-1 at CL = 20 g/l and CI = 0.32 g/l. The interesting observation of the development of antibiotic resistance of Lactobacillus casei in the presence of inulin suggests that the intake of probiotic Lactobacillus casei, may be done along with prebiotic inulin when a patient is treated with antibiotics like norfloxacin. Moreover, the model equation correlating the functionality of growth rate of Lactobacillus casei on lactose and inulin will be helpful in fortifying the probiotic milk products and drugs with prebiotics like inulin.