This lecture covers the concepts of microbial growth, enzyme inhibition, and mathematical models used to analyze growth kinetics. Topics include competitive, non-competitive, and mixed inhibition, Lineweaver-Burk plots, determination of inhibition constants, and calculation of catalytic efficiency. The lecture also discusses the determination of cell numbers through microscopy, dilution techniques, and flow cytometry. Practical applications in water analysis, such as colony counting and flow cytometry for microbial detection, are also explored.