Stoichiometry of cell growth – cell formula and growth equation; respiratory quotient; ATP gain and ATP-based cell yield; Formulation of culture media. Basic concepts – yield coefficients, maintenance coefficient, true and apparent yield. Macro-energetics of cell growth - metabolic heat evolution, energetic efficiency and heat of reaction.
Phases of microbial growth – growth curve; specific growth rate; kinetics of cell growth; dependence of specific growth rate on limiting substrate concentration – shifting order kinetics; Monod model; Other models; Inhibition of cell growth by inhibiting agents, excess substrate and product. Kinetics of microbial product synthesis – dependence on cell growth – Leudeking-Piret model. Sterilization and the kinetics of thermal death of cells.
Modes of microbial growth – shake-flask cultures, fermentor/bioreactor – batch, fed-batch and continuous-flow types. Chemostat - dilution rate and specific cell growth rate – steady state and cell wash-out; Estimation of yield/maintenance coefficients using steady chemostat data. Effect of environmental conditions on growth – dissolved oxygen (DO), temperature and pH; Oxygen transfer – transfer coefficient, OUR, OTR and OSR. Bioreactors – types, selection, design |
