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The kinetic and general growth features of Bacillus thuringiensis var. israelensis were evaluated. Initial glucose concentration (S  ₀) in fermentation media varied from 10 to 152 g/l. The results afforded to characterize four morphologically and physiologically well-defined culture phases, independent of S  ₀ values: Phase I, vegetative growth; Phase II, transition to sporulation; Phase III, sporulation; and Phase IV, spores maturation and cell lysis. Important process parameters were also determined. The maximum specific growth rates (μ  _X,m) were not affected with S  ₀ up to 75 g/l (1.0–1.1 per hour), but higher glucose concentrations resulted in growth inhibition by substrate, revealed by a reduction in μ  _X,m values. These higher S  ₀ values led to longer Phases III and IV and delayed sporulation. Similar biomass concentrations (X  _m = 15.2–15.9 g/l) were achieved with S  ₀ over 30.8 g/l, with increasing residual …