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Monday, October 11, 2004

Beginning with Chapter Six "Microbial Nutrition and Growth"

Like all organisms, microbes desire nutrients in order to live and grow. Some of these requirements include, but are not limited to: nutrients, oxygen, ph, temperature, moisture and reproduction.
Replication is based on the bacterial requirements being met.
BACTERIA ARE GROUPED BY ENERGY ACQUISITION
Photo-auto- trophs derive their energy from sunlight and CO2, a carbon source.Chemo auto trophs derive their energy from sulfer and hydrogen. CO2 is the carbon source.
Chemo auto trophs derive their energy from sulfer and hydrogen. CO2 is the carbon source.
Photo hetero trophs use sunlight as an energy source and organic material as the carbon source.
Chemo hetero trophs derive energy from chemical compounds, and organic compounds as a carbon source. (Humans are in this category)
BACTERIA ARE GROUPED FURTHER BY THEIR RANGES IN ENVIRONMENTAL CONDITION.
Temperature
Psychophile- Cold Range (0-20 degrees C)
Mesophile- Range from 20-40 degrees C (flora)
Thermophile- Range from 45-80 degrees C
Hyperthermophile- over 80 degress C
ph
Most are between 6.5-7.5
Neutrophils-- 6.5-8.5
Acidophils-- less than 6.0 and varying ranges
Alkalinophiles-- more than 8.0
Salinity (Salt content)
Plasmolysis is an issue for most cells, so they cannot stand an increase in salt content.
Halophils can withstand high salinity.
Hydrostatic Pressure Most cells are sensitive to pressures.

Viable Cell Count-- (Bauman book, page 190) Lab Procedure

MEDIA TYPES
Complex Has a variety of ingredients.
Defined Pure chemicals within the mixture. They also need a buffer added to them.(Good source for anti-microbial requirements, AKA growth factors)
Selective Helps to narrow down organism of interest. EX: Glucose salts
Thayer-Martin Isolates N.Gonorrhea, Antibiotics will inhibit growth of fungi, Gram + and Gram - rods, and will allow growth with little competition.
Differential Created in mind that different organisms metabolize different materials in different ways. A bacteria type can change a substance in a recognizable way. EX: Blood agar- "strep test"

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