BIOL 230 Lecture Notes - Lecture 4: Potato Salad, Mycobacterium Tuberculosis, Exponential Growth
Document Summary
A glimpse of history: german physician robert koch (1843 1910) Interested of disease-causing bacteria: developed methods of cultivating bacteria, worked on methods of solid media to allow single bacteria to grow and form colonies. Tried potatoes, but nutrients limiting for many bacteria. In 1882, fannie hess, wife of associate, suggested agar she used to harden jelly: agar is a solidify agent does not provide any nutrients. Introduction: prokaryotes can be found growing in severe conditions, ocean depths, volcanic vents, polar regions. Individual species have limited set of conditions including nutrients. Some microorganisms should be available as cultures- used for teaching and research purposes. Probiotics are in yogurt and these microorganisms are necessary in the food industry. Principles of bacterial growth: prokaryotic cells divide by binary fission. Exponential growth: population doubles with each division: generation time is the time it takes for the population to double. Generation time varies on: species, coli 20 min.
