9.1 How Microbes Grow 9.2 Oxygen Requirements for Microbial Growth 9.3 The Effects of pH on Microbial Growth 9.4 Temperature and Microbial Growth 9.5 Other Environmental Conditions that Affect Growth 9.6 Media Used for Bacterial Growth

Learning Objectives By the end of this section, you will be able to: The study of microorganisms is greatly facilitated if we are able to culture them, that is, to keep reproducing populations alive under laboratory conditions. Culturing many microorganisms…

Learning Objectives By the end of this section, you will be able to: Microorganisms interact with their environment along more dimensions than pH, temperature, and free oxygen levels, although these factors require significant adaptations. We also find microorganisms adapted to…

Learning Objectives By the end of this section, you will be able to: When the exploration of Lake Whillans started in Antarctica, researchers did not expect to find much life. Constant subzero temperatures and lack of obvious sources of nutrients…

Learning Objectives By the end of this section, you will be able to: Yogurt, pickles, sauerkraut, and lime-seasoned dishes all owe their tangy taste to a high acid content (Figure 9.25). Recall that acidity is a function of the concentration…

Learning Objectives By the end of this section, you will be able to: Ask most people “What are the major requirements for life?” and the answers are likely to include water and oxygen. Few would argue about the need for…

Learning Objectives By the end of this section, you will be able to: Clinical Focus Part 1 Jeni, a 24-year-old pregnant woman in her second trimester, visits a clinic with complaints of high fever, 38.9 °C (102 °F), fatigue, and…

Figure 9.1 Medical devices that are inserted into a patient’s body often become contaminated with a thin biofilm of microorganisms enmeshed in the sticky material they secrete. The electron micrograph (left) shows the inside walls of an in-dwelling catheter. Arrows point to…