Effect of Agitation Rate on Growth Yield and Virulence of Bordetella pertussis Strain 509 in Lab Scale Cultivation

Research Paper (postgraduate) from the year 2011 in the subject Biology - Micro- and Molecular Biology, VIT University, course: M.Sc Biotechnology, language: English, abstract: In the present study, effect of agitation rate on growth yield and virulence property of Bordetella pertussis (BP) strain 509 during pilot scale cultivation was investigated. The results indicated significant decrease in growth yield on increasing the agitation rate due to shear stress of bacterial cells. To characterize the shear stress on bacterial cell protein FHA, cell lines such as Vero cells and CHO cells were used to check the adherence property. Finally the virulence property of vaccine culture was screened by Mouse Weight Gain Test (MWGT) and lymphocytosis promoting factor (LPF) test using LACA strains of laboratory mice weighing 14-16 grams. Comparatively more toxicity was observed on higher agitation rates than in optimal and lower agitation. It is evident that higher agitation causes shearing stress in cells inducing more toxicity than optimal agitation which in turn affects the quality of final vaccine.