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How do the little bugs grow?. Growth of Microorganisms. Outline. Vocabulary warning Physical Requirements Chemical Requirements Patterns of Growth Measurements of Growth. Vocabulary Warning. There is a lot of vocabulary in the next two chapters
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How do the little bugs grow? Growth of Microorganisms
Outline • Vocabulary warning • Physical Requirements • Chemical Requirements • Patterns of Growth • Measurements of Growth
Vocabulary Warning • There is a lot of vocabulary in the next two chapters • Much of the vocabulary is very specific in meaning and descriptive • These terms are extremely relevant to clinical microbiology and are part of the professional lexicon of the field.
Physical Parameters of Growth • Like all machines, microbes have operational conditions. • Though microbes dominate every niche on the planet, not all microbes are everywhere. • The physical conditions of growth are directly linked to physiology.
Example of Physical Parameters = Psycrophile = Psycrotroph = Mesophile 10° C 100° C = Thermophile = Hyperthermophile 0° C 37° C
Other types of physical conditions • Salt concentration • Halophile • pH • Basophile • Acidophile • Water Concentration • Xerophile
Why do these boundaries exist? • Structural Integrity of Cell Components • Protein Denaturation • Chicken and Egg Problem • Natural Environment of Cells • The Story of Hansen’s Disease
Chemical Requirements for Growth. • What elements do we need to form the major macromolecules? • Carbon • Nitrogen • Sulfur • Phosphorus
What about Oxygen and Hydrogen? • Both can be gotten from water. • Oxygen is a special case • Aerobe – organism that requires oxygen (O2) • Anaerobe – organism that does not require oxygen (O2) • Modifying Language • Obligate • Facultative
Carbon, Nitrogen, Sulfur, and Phosphorus • Heterotroph vs. Autotroph • Must be present in a usable form • Is this everything you need to make a cell?
Other Components • Trace Elements (i.e. metals) • Vitamins • Unique Compounds
Types of Media • Complex Media • Defined Media
Can we culture everything? NO, many things remain unculturable in today’s micro lab and these are proving to be some of the most interesting organisms.
Pattern of Growth = Lag Phase = Log Phase = Stationary Phase = Death Phase
Caveats to Model • Small Initial Inoculum • Media can be utilized • Culture is not used to the media • Generation Time, how can you calculate it?
Measuring Growth • Direct • Indirect