2. CONTENT
ď History of Bacteria.
ď Introduction of bacteria.
ď Ways of classification.
ď Groups of Bacteria.
ď Comparison b/w Prokaryotes & Eukaryotes.
ď Comparison with other Kingdoms.
4. What are bacteria?
⢠Single celled organisms
⢠Very small E. Coli O157:H7 can
make you very sick
⢠Need a microscope to see
.â˘Can be found on most materials
and surfaces
Streptococcus
⢠Billions on and in your can cause strep
throat.
body right now
This E. coli helps you
digest food.
5. What do they look like?
Bacilli
⢠Three basic shapes
â Rod shaped called bacilli
â (buh-sill-eye)
â Round shaped called cocci
Cocci
â (cox-eye)
â Spiral shaped
⢠Some exist as single cells,
others
cluster together Spiral
Cluster of cocci
6. Bacteria are ALIVE!
⢠What does it mean to be
alive?
-They reproduce
(make more of
themselves)
- They need to eat
7. How do bacteria
reproduce?
⢠Grow in number not in size
â Humans grow in size from child to adult
⢠Make copies of themselves by dividing in half
â Human parents create a child
8. How do bacteria eat?
⢠Some make their own food from Photosynthetic
sunlightâlike plants bacteria
⢠Some are scavengers
â Share the environment around them
⢠Example: The bacteria in your stomach are now
eating what you ate for breakfast
Harmless bacteria on
the stomach lining
⢠Some are warriors (pathogens)
â They attack other living things
⢠Example: The bacteria on your face can attack skin
E. Coli
causing infection and acne O157:H7
is a pathogen
9. BRIEF HISTORY:
In a 1683 letter to the Royal
Society
Of London, Anton van
Leeuwenhoek
Described microscopic
âSTREAKS &
THREADSâ, among his tiny
animals.
The streaks and threads
remained nameless until
1773,
10. In 1773, when the Danish
scientist
Otto Frederick Muller
christened them bacilli.
Bacilli is the plural form
of the Latin word Bacillus
meaning but not all
âbacilliâ were rods. Some
were spiral and some
were circular, & âbacilliâ
would not do.
11. Therefore, in the 1850s, The
French investigator Casimir
Davaine began calling a
microscopic creatures
âBACTERIAâ, even though this
derivatives of the Greek
bacterion also means rod. In
the next few decades
âbacteriaâ came to refer to all
the micro-organisms in that
group, and the word âBcillusâ
was reserved for rod forms
only.
12. Archaebacteria vs Eubacteria
Archaebacteria
Archaebacteria have prokaryotic
cells, which means they don't have
a nucleus. While they usually live in
groups, they are considered
unicellular, meaning they have one
cell. Archaebacteria can make their
own food, making them autotrophs.
They can live in hot springs, deep
ocean vents with no light and under
extreme pressure, and in very salty
lakes.. so basically, all extreme
environments. Some of them can
even live with no oxygen
14. Comparison chart
Archaebacteria Eubacteria
Cell Membrane: Branched chain ether Straight chain ester
linked lipids. linked lipids.
tRNA: Lacks thymine in tRNA. Thymine present in
tRNA.
RNA polymerase: Ten subunit RNA 4 subunit RNA
polymerase core. polymerase core.
Role in ecology: Role in bio-geochemical Vital in nutrient recycling.
cycles is unexplored.
15. DNA: DNA is closer to DNA differs from
eukaryotes (sent on eukaryotes.
to daughter cells via
mitosis)
Definition: Single celled organisms All true bacteria or group
without anycell of unicellular prokaryotic
organelles or nucleus. microorganisms.
Morphology: Occur in various shapes Various shaped bacteria
like spheres, rods, plates have been identified like
and spirals. rods, cocci, spirals,
comma shaped, tightly
coiled etc.
Cell Wall: Lacks peptidoglycan. Peptidoglycan is present.
Extremophilic: Yes. Some.
28. 5. Spirochetes
⢠Cell shape :
slender,
helically
coiled(spiral).
⢠Most of them
are gram
negative Example : spirochaeta
29. 6.Spiral and Curved bacteria
⢠Cell shape: helically coiled
rods , some with one or
more complete turns.
⢠Gram negative
⢠Habitat : aquatic,
reproductive organs,
intestinal tract and oral
cavity of animals (including
humans)
Example :vibrio species
30. 7.Gram negative aerobic rods and
cocci
⢠Cell shape : rod, oval ,
spherical.
⢠Gram negative
⢠Habitat : soil and
aquatic environment ,
salt brines .
Example: brucella
species
31. 8.Gram negative facultative anaerobic
rods
⢠Cell shape : typically ,
short rod
⢠Gram negative
⢠Habitat: aquatic
environment, soil,
urine, faeces
Example : E.coli
32. 9.Gram negative anaerobic rods
⢠Cell shape : rod , straight
or curved , exhibiting
considerably
polymorphism
⢠Habitat: natural cavities
of
humans and other Example :bacteroides
animals also intestinal
tracts of insects.
33. 10.Gram negative cocci and
coccobacilli
⢠Cell shape : cocci in pairs
(diplococci )some coccobacilli
occur single and in pairs
⢠Gram negative
⢠Habitat : on mucous
membrane of humans and
other animals
Example : neisseria
gonorrhoaea
34. 11.Gram negative anaerobic cocci
⢠Cell shape: very small to very
large spherical cell in pairs ,
masses, or chains,
⢠Habitat : respiratory and
intestinal tracts of human and
other animals
Example :veillonella
35. 12. Gram negative chemolithotrophic
bacteria
⢠Cell shape : spherical,
rod , spiral,
multilayered
membranes in some
species
⢠Gram negative
⢠Habitat : soil, sewage ,
aquatic environments ,
natural environment
with large amount of
Example: nitrosomonas
sulphur , iron or
manganese
36. 13.Methane producing bacteria
⢠Cell shape : spherical , rod
spiral
⢠Gram positive or gram
negative
⢠Habitat: gastrointestinal
tract of animals , aquatic
and sewage
Example:
methanospirillum
37. 14. Gram positive cocci
⢠Cell shape : cocci occurring singly or
in pairs , chains or clusters
⢠Gram positive
⢠Habitat: soil , fresh water , skin and
mucous membrane of warm
blooded animals including human
Example :
streptococcus
38. 15. Endospore forming rods and cocci
⢠Cell shape; rods
⢠Gram positive
⢠Habitat :soil , air , aquatic,
intestinal tracts of animals
Example : bacillus
39. 16.Gram positive asporogenous , rod
shaped
⢠Cell shape: bacilli occurring
singly or in chains
⢠Gram positive
⢠Habitat ; dairy products ,
grains and meat products ,
water, sewage , oral cavity
and vagina
Example : lactobacillus
40. 17.Actinomycetes and related
organisms
⢠Cell shape: irregular
rod shaped ,
filaments and
branched filaments
⢠Gram positive
⢠Habitat: soil , aquatic ,
air and animals
mycobacterium tuberculosis .
41. 18.The Rickettsias
⢠Cell shape : short rods or
ovals , often pleomorphic
⢠Gram negative
⢠Habitat: insect carriers , birds
and mammals
Example: rickettsia akari