lecture 1

Microbiology
29.03.2016
Helmut Pospiech
Microbiology
• from Greek
– mīkros, - "small”
– bios, "life”
– -logia)
àthe study of small, single-celled organisms
Brock Biology of Microorganisms, 13th ed.
Bacteria
(Prokaryotes)
Viruses
Brock Biology of Microorganisms, 13th ed.
Unicellular
Eukaryotes
What are microorganisms?
Bacteria
Archaea
Protozoa
Fungi including molds
and yeasts
• Algae
• Viruses (although viruses
•
•
•
•
do no have an own
metabolism and are
therefore no orgamisms)
Brock Biology of Microorganisms, 13th ed.
What comes into your mind when thinking about microbiology?
Where can microorganisms be found?
Brock Biology of Microorganisms, 13th ed.
Microorganisms have a major impact
on the cycle of matter
Brock Biology of Microorganisms, 13th ed.
Modern microbiology has a been of
high importance for human well-being
The end of the terror of infectious diseases
Brock Biology of Microorganisms, 13th ed.
The end of the terror of
infectious diseases – How
to find the cause of an
disease?
Robert Koch
What comes into your mind when
thinking about microbiology?
Brock Biology of Microorganisms, 13th ed.
The tree of life
Brock Biology of Microorganisms, 13th ed.
The tree of life
Prokaryotes
Brock Biology of Microorganisms, 13th ed.
The Reign of Microorganisms
is not over yet!
Prokaryotes Vs Eukaryotes
– a question of organisation
• Prokaryotes have no
membrane-engulfed
organelles
• Cells are usually smaller in
size
• Simpler in organisation
Brock Biology of Microorganisms, 13th ed.
Size matters!
Brock Biology of Microorganisms, 13th ed.
A Microscope – still one of the
microbiologist’s best friend
Brock Biology of Microorganisms, 13th ed.
Brock Biology of Microorganisms, 13th ed.
The Structure of the
Prokaryotic Cell
Intracellular structures of prokaryotes
• Poly-β-hydroxyalkanoates
– Energy storage
• Magnetosomes
– Fe4O3
– Magnetotaxis
• Gas vesicles
– Allow floating
– Planctonic organisms, e.g. in
cyanobacteria
• Polyphosphate or sulfur body
• Endospores
The cytoplasmic membrane
Brock Biology of Microorganisms, 13th ed.
Eubacteria/Eukaryotes and Archaea
have different type of lipids
• Eukarya/Eubacteria – glycerol ester of fatty acids
• Archaea – glycerol ether of isoprenoids
Brock Biology of Microorganisms, 13th ed.
Eubacteria/Eukaryotes and Archaea
have different type of lipids
cholesterol
• Eubacteria usually without
sterols such as cholesterol
• But squalene or hopanoids
Brock Biology of Microorganisms, 13th ed.
Eubacteria/Eukaryotes
and Archaea possess
different types of lipids
Brock Biology of Microorganisms, 13th ed.
The functions of the cytoplasmic
membrane
Brock Biology of Microorganisms, 13th ed.
The control of what gets in
and what gets out
• Passive transport
– along a concentration
gradient
– often inefficient
• Active transport
– Requires energy
consumption
Brock Biology of Microorganisms, 13th ed.
3 different types of simple
transporters (selective pores)
Brock Biology of Microorganisms, 13th ed.
Examples of Simple Transporters
in E. coli
Brock Biology of Microorganisms, 13th ed.
Phosphotransferase, an example for a
group translocation system in E. coli
Brock Biology of Microorganisms, 13th ed.
Why does group translocation (coupling of glucose transport and phosphorylation)
facilitate glucose uptake?
Answer: Because of the glucose phosphorylation, the intra cellular concentration of
(free) glucose remains extremely low!
ABC (ATP binding cassette)
transporters
• More than 200 different
ABC transporters known
in prokaryotes
• Very high affinity of the
binding protein to the
substrate (< 1 µM)
• For the uptake of
–
–
–
–
Sugars
Amino acids
Sulfate, phosphate
Trace metals
Brock Biology of Microorganisms, 13th ed.
The cell
wall of
Eubacteria
Brock Biology of Microorganisms, 13th ed.
The structure/composition of peptidoglycan
lysozyme
transpeptidase
β − lactam
antibiotics
(penicillins,
cephalosporins)
Brock Biology of Microorganisms, 13th ed.
The cell wall
of gramnegative
bacteria
Brock Biology of Microorganisms, 13th ed.
The cell wall
of grampositive
bacteria
Brock Biology of Microorganisms, 13th ed.
The cell wall of Mycobacteria
• Mycobacteria
are pathogens
that cause e.g.
tubercolosis
and leprae
• Slow growing
• Special cell
wall structure
haves evading
immune
system of the
host
Brock Biology of Microorganisms, 13th ed.
The impact of cell wall
structure on taxonomy
– the Gram staining
Brock Biology of Microorganisms, 13th ed.