Question
Answer
Side 3
Death Phase
Cells gradually die off in decline phase.
You can estimate bacterial numbers
indirectly by:
Metabolic activity
and
Dry weight
Most Probable Number (MPN)
Statistical estimating technique that is used to estimate
#'s of bacteria in liquid medium.
Fungus would be
filtered, dried and weighed.
Standard Plate Count
Each bacterium grows in to a single colony which is
reported as a number of colony forming units (C.F.U.)
Count by pour plate method or spread plate method.
Filtration
Bacteria stay on the surface of the membrane filter and
then transferred to medium to be grown and counted.
Direct microscopic count
the microbes in the measure volume of bacteria are
counted with the use of a specially designed slide (cell
counter)
Spectophotometer
Indirect method of measuring microbial growth. It is used
to determine turbidity (cloudiness) by measuring the
amout of lifth that passes through a suspension of a cell.
Measurement of metabolic activity of
the population
Indirect method of measuring microbial growth. Oxygen
consumption and acid production
......
Completely independent neighboring
microbes
Two different oragnisms that live side by side.
Mutualism
each organism benefits from another
Commensalism
One organism benefits but causes no harm.
Microbiota
Normal microbes that live on humans and cause no harm
unless they have an opportunity (opportunists)
Eg. cut
Compete for space on humans and
in colon.
Bacteria and yeast
Antibiotics may kill _____ bacteria
and cause _______ one to grow
good
pathogenic
Moisture
Most bacteria favor moisture
T.B and Staph can withstand _____
and can live in ______ or food for
_____ periods.
drying
dust
long
Drying food is one method of
food preservation
Photosynthetic bacteria
reacquire light
Most bacteria like __________
envirnoments.
warm, dark, alkaline and moist environments.
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Properties of
Spirochetes
-helical or coiled form of spiral shape
-will stain Gram -
-very fast and motile
-borralia disease is caused by ticks – Relapsing Fever, fever that comes and
goes, another spirochete
-Genus Leptospira, leptosporosis – can cause severe kidney and liver
disease
-dogs rats and wild animals pick it up and carry it in their urine
-easily picked up in natural waters, look for signage
Types of Spirochetes
•Treponoma palladium
•Syphilis can be treated
•if untreated it will infiltrate entire body
•Causes brain degeneration and sores and a very ugly death
•Borrelia spp.
•Lyme disease
•difficult to diagnose and treat
•moves throughout the body
•joints,heart, liver, spleen, Bullseye rash on chest
•3 months or more to treat constant medication
•Borrelia species also cause relapsing fever
•Leptospira
•found in water or soils
•ingestion of water
•urination of animals spread it
•kidney inflamation
Properties of
Chlamydias
•obligate intracellular bacteria
•reticulate bodies (when in cell)
•offspring is elemental body
•elemental bodies carry infection to other cells

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- Fall '10
- paxton
- Microbiology, Bacteria, DNA, RNA
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