Temperature greatly impacts the growth, survival and death of microorganisms. There are several types of bacteria that grow at different temperature ranges: psychrophiles grow best below 15°C, psychrotrophs and mesophiles grow between 15-45°C, thermophiles grow between 45-80°C, and hyperthermophiles grow above 80°C. Bacteria can grow below 0°C but more slowly, and their growth rates increase with temperature until an optimum range is reached, after which higher temperatures cause enzyme denaturation and damage cell structures. The temperature danger zone for food between 40-140°F allows most rapid bacterial growth.

1. Effect Of
Temperature on
Environmental
Fate of
Microorganisms
Presented By; Amna Shahzadi
Submitted To: Dr. Sagheer Ahmed Sagheer

2. Temperature
Temperature is the most
important factor that
determines the rate of
growth, multiplication,
survival, and death of all
living organisms..
Microbial membrane are
disrupted by temperature
extremes..
At very low temperatures
membranes also solidify
and enzymes also do not
function properly..
High temperatures
damage microbes by
denaturing enzymes,
transport carriers, and
other proteins..

3. Types of temperature
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Minimum growth
temperature
The lowest temperature at
which organisms grow is the
minimum growth
temperature.
Optimum growth
temperature
The temperature at which
the most rapid rate of
multiplication occurs.
Maximum growth
temperature
The highest temperature at
which growth occurs. A
temperature only slightly
above this point frequently
kills the microorganisms by
inactivating critical enzymes.

4. What are the different types of bacteria that
grow at different temperatures?
01
02
03
04
05
(60 degrees C and upwards)
Hyperthermophile
(optimal growth between 45 and 122
degrees)
Thermophile
(20 and 45 degrees C)
Mesophile
(will survive at 0 degrees C, but prefer
mesophilic temperature..
Psychrotrophs
(-15 and 10 degrees C or lower‫۔‬.
Psychrophiles

5. Classification of bacteria according to
growth temperature
1. Cold‐tolerant bacteria.
2. Have optimal and
maximal growth
temperatures above 15
and 20°C, respectively.
3. Psychrotrophic bacteria
and fungi are the principal
cause of spoilage of
refrigerated food.
4. Examples: Pseudomonas,
Aeromonas, Bacillus,
Clostridium, etc.
Psychrotrophs
1. Grows best in moderate
temperature.
2. Temperature range: 20°C
to 45°C.
3. Examples: Escherichia
coli, Streptococcus
pneumoniae, etc.
Mesophiles
1. The term psychrophile
was first used by S.
Schmidt-Nelson.
2. Extremophilic organisms
that are capable of
growth and reproduction
in cold temperatures
3. Temperature range:
−20°C to +10°C.
4. Examples: Oscillatoria,
Chlamydomonas nivalis,
Methanogenium, etc.
Psychrophiles / cryophiles

6. Classification of bacteria according to
growth temperature
1. Thrives in extremely hot
environments.
2. Temperature range: 80°C to 113°C.
3. First discovered by Thomas D. Brock
in 1965 , in hot springs inYellowstone
National Park, Wyoming.
4. The cell membrane contains high
levels of saturated fatty acids to retain
its shape at high temperatures
5. Examples: Sulfolobus,
Methanococcus jannaschii,
Thermotoga, etc.
Hyperthermophiles
1. Derived from Greek word
thermotita meaning heat
and philia meaning love.
2. Heat-loving
microorganisms.
3. Grow at 50°C or higher.
Their growth minimum is
usually around 45°C and
often optima between 50
and 80°C.
4. Examples: Thermus
aquaticus, Geogemma
barossii, etc.
Thermophiles

7. Growth rate of bacteria

8. Insert the title of your subtitle Here
Can Bacteria Grow Below
0 Degrees?
The microorganisms live in every part of the biosphere, and some of
them are even capable of growing at low temperatures, including those
below the freezing point

9. At temperatures below their optimum for growth
microorganisms will become increasingly unable
to sequester substrates from their environment
because of lowered affinity, exacerbating the
anyway near-starvation conditions in many natural
environments‫۔‬
How Does Low
Temperature Affect
Microbial Growth?

10. Does Bacteria Grow In High Temperatures?
Bacteria can live in hotter and colder temperatures than humans,
but they do best in a warm, moist, protein-rich environment that is
pH neutral or low acid. There are exceptions: some bacteria thrive
in extreme heat or cold. some can survive under highly acidic or
extremely salty conditions.

11. Some species of microorganism can
grow at temperatures as low as -10o C,
and others at temperatures as high as
100o C - or higher. ... As the
temperature increases, molecules move
faster, enzymes speed up metabolism
and cells rapidly increase in size‫۔‬
Why Do Bacteria Grow
Faster At Higher
Temperatures?

12. Why Do Bacteria Die At High Temperatures?
When the temperature gets hot enough, the enzymes in the
bacterium are denatured, meaning they change shape. This change
renders them useless, and they're no longer able to do their work. ...
Heat can also damage the bacterium's cell envelope. Proteins and
fatty acids making up the envelope lose their shape, weakening it.

13. Bacteria grow most rapidly in the range of temperatures between 40 °F and 140 °F, doubling in number
in as little as 20 minutes. This range of temperatures is often called the "Danger Zone." Never leave food
out of refrigeration over 2 hours.
What is the
temperature
danger zone
for food?

14. Section Break
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What Temperature Kills Bacteria In
Washing Machine?
60 degrees Celsius
Your washing machine is an easy breeding ground for microbes and needs regular
disinfection; The temperature that kills bacteria is 60 degrees Celsius and above.
A maintenance wash in the best way to keep your washing machine free from
harmful germs

15. ANY
QUESTION?

16. Thank you