MICROBIOLOGY – ALCAMOGROWTH AND GROWTH PHASES

Growth Human Terms:

Growth = __________ Microorganism Terms:

Growth = __________

Growth Binary Fission – bacteria reproduce

__________ :Chromosome __________Cell __________Plasma membrane __________ in at center__________ __________ distributes evenlyCell wall thickens to separate dividing cells

Growth Binary fission – gives __________ to

bacteria The first bacterium ________ _______ It __________ and becomes a new,

young cell again The original __________ (billions of

years old) is still among us

GrowthReproduction:

__________ __________

20 Generation21 Generation

22 Generation

23 Generation

Generation Time Time between _______ __________

when bacteria grows and develops its unique features

Also called “________ _________” A determining factor in the __________ of

time that passes between entry of an organism into our bodies and the __________ of disease symptoms

Growth Each microorganism has it’s own

characteristic __________ __________

Range: Usually 1 to 3 __________ __________ 20 minutes (E. coli) __________ 33 hours (T. pallidum -

syphilis)

BACTERIAL GROWTH IS LOGARITHMIC

GrowthGrowth Rates If after 48 hours of __________, a

colony is pinpoint size, __________ GT is indicated.

If after 48 hours, the __________ is ¼” wide, __________ GT is indicated.

Growth ExampleE. coli has a 20 minute __________ __________ under ideal conditions:

Time # of Bacteria0 1

1 hour 8

2 hours 64

3 hours 512

10 hours > 1 billion

36 hours Cover face of the earth

GrowthGrowth Rates Exponential growth signifies ideal

__________ and maximum __________ But the __________ __________ of

bacteria is never fully realized due to environmental __________

Growth Phases Many dynamics __________ the

population of bacteria over the course of __________

A certain population’s history may begin when:Several bacteria enter the __________

__________ tractSeveral bacteria are transferred to a tube of

__________ __________ in a lab

Growth PhasesLag Phase: First few hours of __________ __________ Period of __________ to new environment If an __________, WBC’s can be

__________ some cells If in a lab, some cells may die from

__________ __________

Growth Phases The activity of the remaining cells is

intense as they:Store __________Synthesize __________Prepare for __________ __________

But the curve remains at a __________, where the number of cells reproducing __________ the number of cells dying

Growth PhasesLog Phase: Also called “__________” phase The mass of each cell increases

__________ and __________ follows As each generation time passes, the

number of bacteria __________ and the graph rises __________

Growth Phases In humans, disease symptoms arise during

the __________ __________Bacterial population is high enough to

__________ __________Fever, __________, tissue damage arise

In a lab, visible signs of growth will be seen: colonies will appear on ________ ________broth media will become __________

Growth Phases Research experiments are usually done

during the __________ __________ because the population of bacteria is at its __________ __________

Growth PhasesStationary Phase: Period of __________ __________

numbers Reproduction rate = __________

__________ No change in total number of __________

Growth Phases Stationary Phase: In humans:

the __________ __________ may be destroying the bacteria

antibiotics have been __________ In the lab:

nutrients are becoming ____________________ __________ are building upoxygen or water could be in __________

__________

Growth PhasesDecline Phase: Environment becomes progressively

__________ and exerts its __________ __________

pH is changing oxygen and nutrients are __________ accumulation of __________

Growth Phases Decline Phase: Number of cells __________ __________

the number of new cells formed Spore forming species will start to produce

__________ Flagellated species will try to __________ to a

new location For other species, culture death is __________

Things That Affect GrowthTemperature Different species grow at different

temperatures__________ – grow best between 0oC and

20oC__________ – grow best between 20oC and

40oC__________ – grow best between 40oC and

90oC

Things That Affect Growth Temperature Most bacteria are __________,

especially __________ __________ that grow in the human body (37oC)

When the body’s temperature rises to 40oC (104oF) there is a slightly _________ affect on bacterial ________

The lab incubator is set at 37oC to __________ bacterial growth

Things That Affect Growth Temperature Some __________ can grow at refrigerator

temperatures and cause __________ __________

Staphylococci can grow in the refrigerator and deposit their __________ on cold cuts, salads and leftovers

If these foods are eaten without further cooking, __________ __________ can result

Things That Affect Growth Temperature

__________ outbreak in a restaurant in 1991 Restaurant employee prepared Caesar salad

dressing which contains raw egg It may have remained at room __________ too

long before being served Within 3 days, 15 people were __________

with diarrhea, fever, cramps and __________

Things That Affect Growth Oxygen __________ bacteria – require __________

to grow __________ bacteria – require an oxygen-

free environment to growIncludes __________ species that cause

tetanus and botulism __________ bacteria – grow in either the

presence or __________ of oxygenincludes many staphylococci, streptococci and

bacilli

Things That Affect Growth pH Bacteria have a __________ internal

environment Will tolerate a pH range of __________ Human blood and tissues have a pH of

__________ Provides a __________ environment for

disease causing bacteria to __________

Things That Affect Growth pH

Certain bacteria are __________ __________ Useful in the food and dairy __________ Lactobacillus and Streptococcus produce the acid

that converts: milk to ____________________ to sour creammilk curds to __________

These bacteria __________ __________ __________ to good health even when eaten in large quantities

Things That Affect Growth pH Most bacteria do not grow well under

__________ __________ Stomach’s __________ __________

prevents disease Certain __________ __________ are hardly

ever contaminated with bacteriaCitrus fruits__________ Tomatoes

Things That Affect Growth Pattern of Nutrition

Bacteria (like us) need:__________ __________ to serve as energy

sources and as raw materials for synthesis of cell __________

Things That Affect Growth Pattern of Nutrition Two patterns for obtaining nutrition:

__________ – can make their __________ food using inorganic carbon, water and sun’s energy

__________ – obtain preformed organic molecules from the __________ for structural components and energy○ __________ – feed exclusively on dead organic

matter such as rotting wood○ __________– feed on living organic matter such as

human tissues

Things That Affect Growth Bacterial Cultivation In the lab, bacteria are grown in:

__________ __________ containing water, beef extract and peptone (protein supplement)

__________ __________ – contains the same, plus agar, a polysaccharide derived from marine algae

*Most bacteria __________ __________ in these

Things That Affect Growth Bacterial Cultivation Some bacteria require __________ or

__________ media The streptococci that cause strep throat and

scarlet fever grow well when __________ __________ is added to the media

__________ __________– heated before solidification to disrupt the red blood cells and release __________

Sometimes called __________ __________

Things That Affect Growth Bacterial Cultivation

__________ __________– contain ingredients to __________ the growth of certain bacteria in a mixture while __________ the growth of others__________ salt agar – high salt content

__________ the growth of most bacteria, but allows for staphylococci to grow

__________ methylene blue agar – contain dyes that __________ Gram-positive bacteria, but __________ growth of Gram-negative

Things That Affect Growth Bacterial Cultivation __________ __________– makes it easy to

distinguish colonies of one organism from __________ of another on the same plate

MacConkey’s agar contains __________ __________ as well as lactoseColonies of bacteria that __________ __________

are redColonies of bacteria that __________ ferment

lactose are colorless

Things That Affect Growth Bacterial Cultivation __________ __________– not

chemically definedExact components and quantities are not

knownSome bacteria will only grow on natural

media __________ __________ - chemically

definedThe nature and amount of each component

is known

Things That Affect Growth Intermicrobial Relationships __________ – situation in which two

populations of organisms interact in a __________ and __________ association

Benefits obtained may involve:food__________ support

Things That Affect Growth Intermicrobial Relationships __________ – symbiosis that benefits

both populations Bacteria living on roots of plants:

Bacteria trap __________ for plants to synthesize __________ __________

Plants provide a __________ environment and __________ __________ for bacteria

Things That Affect Growth Intermicrobial Relationships __________ – one population receives

benefit from the relationship while the other is not __________ or __________

Bacteria that inhabit human skin:__________ has a place to live and foodWe are not helped or __________ in any

way

Things That Affect Growth Intermicrobial Relationships __________ – two populations live

together and accomplish what neither could alone

__________ __________ – two populations of bacteria (usually rods and spirochetes) must be present for __________ of the __________ __________ to occur

Things That Affect Growth Intermicrobial Relationships __________– symbiosis is beneficial to one

population (__________) but harmful to the other (__________)

The bacteria of all human diseases are __________

Applications Industrial: __________ __________

products Penicillin Vinegar Wine Pickles Beer Cheese Alcohol

Medical: Phases of disease parallel __________ __________ of pathogen