CLS 311 Basic Microbiology Mrs Amany Ahmed Niazy Bacteria are the smallest and most versatile independently living cells known Microorganisms Acellular Cellular Prokaryotes Eukaryotes ID: 220043
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Slide1
BACTERIA
CLS 311: Basic MicrobiologyMrs. Amany Ahmed NiazySlide2
Bacteria are the smallest and most versatile independently living cells known. Slide3
Microorganisms
Acellular
Cellular
Prokaryotes
Eukaryotes
Archaea
Bacteria
Viruses
P
rotozoae
Fungi . Slide4
History
Anton van Leeuwenhoek (1632-1723):He is the father of microbiology. Known for his invention of the single-lens microscope.Bacteria were first observed by him in 1676.Slide5
History
Louis Pasteur (1822-1895).discoveries helped to formulate “germ theory of disease” .Invention of pasteurization. Slide6
History
Robert Koch (1843-1910):German physician. He confirmed the germ theory of disease.He became famous for isolating Bacillus anthracis, the Tuberculosis bacillus and Vibrio cholerae and for his development of Koch's postulates
.
He won a Nobel Prize on 1905.
Monument to Robert Koch in BerlinSlide7
Prokaryotes
There are two major types of prokaryotes:Bacteria.Archaea
(also called
archaebacteria
)
are often found in extreme environments (Oxygen
-free
environments concentrated
salt-
water hot
, acidic
water), and while they are clearly
prokaryotic, they have evolved separately from bacteria.
Prokaryotic cells possess simpler structures than eukaryotic cells
, since they do not have a nucleus or many cytoplasmic organelles.Slide8
Bacteriology
It is a branch of microbiology that is concerned with bacteriaBacteria – single celled organism that multiply by binary fissionLarger and more complex than virusesViable under light microscopeProkaryotic, has both DNA and RNASlide9
Introduction
Bacteria (plural), Bacterium (singular).Bacteriology
The
study of
bacteria.
Bacteria are unicellular microscopic prokaryotes.
Bacteria are ubiquitous in every habitat on Earth, growing in soil, acidic hot springs, radioactive waste, water, and deep in the Earth's crust, as well as in organic matter and the live bodies of plants and animals.
Bacteria are vital in recycling nutrients such as the fixation of nitrogen from the atmosphere and decomposition of dead organic materials.Slide10
Morphological features of bacteria
SizeUnit of microbial measurement is the micrometer (
m), formerly micron (
) which is equal to:
1
m = 1/1000 of a millimeter (mm)
Average size of the bacteria generally varies from 0.5 – 2
m in diameter and 2 – 8
m in length. Slide11
Fundamental ShapesBacilli (bacillus, singular) – rod shaped organisms
Cocci (coccus, singular) – spherical or round organismsSpirilla (spirillum, singular) – spiralled or comma-shaped organisms
Bacilli
Cocci
SPIRILLUMSlide12
Bacterial Arrangements
Two factors that affect bacterial arrangements:Plane of division Position taken after cell divisionSlide13Slide14
Pairs:
– diplococci (e.g. N.gonorrheae)
DIPLOCOCCISlide15
Chains
– streptococci,
STREPTOCOCCISlide16
Grapelike clusters
– staphylococci
STAPHYLOCOCCISlide17
Groups of four
– tetrads (e.g.,
Peptococcus
)
TETRADSSlide18
Packets of eight
–
cuboidal
(e.g.,
Sarcinae
)
PACKETS OF EIGHTSlide19
Palisades (slipping)
– organisms tend to place themselves side by side (e.g.,
Corynebacterium
)
PALISADESSlide20Slide21
CLASSIFICATION and TAXONOMYSlide22
What is Taxonomy
Greek words “taxes” – arrangement, “nomos” – law
The science of classification.
The branch of biology concerned with the classification of organisms into groups based on similarities of structure, origin, etc.Slide23
Classification of Organisms
Based on the is based on similarities and differences in genotypes and phenotypesMicrobiologist traditionally emphasize placement and naming of bacterial species into three categoriesFamily (similar to Human clans)Genus (equivalent to human last name)Species (equivalent to human 1st
name) Slide24Slide25Slide26Slide27Slide28
Nomenclature
Nomenclature provides naming assignments for each organism.Assignment of names for purposes of communication and identificationUse a binomial systems of nomenclatureStandard rules for bacterial names:The name of the family is CAPITALIZED
and has an
aceae
ending (
ex:
E
nterobacteri
aceae
)
Binomial nomenclature
Genus & species
Escherichia coli
Genus name is always capitalized Species name is never capitalized coli Both names are always either italicized or underlined
Abbreviation: E. coliSlide29
The plural of genus
is genera and there are many genera in the family EnterobacteriaceaeEx: Famliy
:
Enterobacteriaceae
Genus:
Escherichia
Species:
coliSlide30
The
International Committee on Systematic Bacteriology (ICSB) maintains international rules for the naming of bacteria and taxonomic categories and for the ranking of them in the International Code of Nomenclature of Bacteria.
Kingdom
Bacteria
Phylum
Proteobacteria
Class
Gamma
Proteobacteria
Order Enterobacteriales
Family Enterobacteriaceae Genus
Escherichia Species Escherichia coli e.g.
Escherichia coliSlide31
Identification
Application of classification & nomenclature to assign proper name to unknown organism andplace it in its proper position within classification system.