Microbial Growth: Understanding Cell Division and Measurement Techniques

This lecture covers the fundamental concepts of microbial growth, focusing on the increase in cell numbers rather than size. The instructor explains the process of cell division, including elongation and septum formation, leading to the generation of two cells from one. The lecture details the mathematical expressions for calculating generation time and growth rates, emphasizing the significance of doubling time in microbial populations. Various methods for measuring microbial growth, such as optical density and viable cell counts, are discussed, along with the use of flow cytometry for accurate cell quantification. The instructor also addresses the growth curve in batch systems, highlighting the lag, exponential, stationary, and death phases. The importance of substrate consumption and product formation in bioreactors is explained, along with the factors affecting specific growth rates. The lecture concludes with practical applications in environmental microbiology, particularly in analyzing water quality and microbial concentrations in different water sources.