Transcript M01cStructureAppendages

Microbiology: Structure.
- Flagella
- Pilli, Fimbriae
- Capsule
- Storage granules
- Endospores
Kophotrichous
Amphotrichous
Vibrio cholerae
Pseudomonas.
Spirillum
GLIDING MOVEMENT:
Flavobacterium, Flexibacter,
Cytophaga, Saprospira. Masses
of bacteria (Flavobacterium)
gliding away from the center of
the colony.
S Motility:
A Motility:
Evidence that focal adhesion complexes power bacterial gliding motility. Mignot T. et al. Science 9
February 2007, 315 p853.
Chemotaxis towards capillary tube filled with amino acids.
Tracks of motile bacteria swarming around an algal cell (white). The bacteria are showing positive
aerotaxisby moving toward the oxygen-producing algal cell.
Aerotaxis towards oxygen.
PHOTOTAXIS: scotophobotaxis.
Scotophobic accumulation of the phototrophic bacterium Thiospirillum jenense at
wavelengths at which its pigments absorb.
Phototaxis.
Migration towards light of an entire colony of the purple phototrophic bacterium
Rhodospirillium centenum.
Magnetospirillum magnetotacticum containig
magnetosomes (magnetite: Fe3O4)
Synthesis of P pilus.
FitsZ, tubulin homolog, and principal component of
the cytokinetic Z-ring, that constricts the middle of
the dividing bacteria. MinCD is an inhibitor of Z-ring
assembly that oscillates rapidly from pole-to-pole,
ensuring that the Z-ring forms only at the midcell
position.
MreB, first bacterial actin-like protein that forms
helical filaments just beneath the bacterial cell
surface. It helps determine the shape of rods,
filaments, and helical bacteria and plays a role in
chromosome segregation.
ParM, an actin-like protein that assembles in twostranded helical filaments that are almost identical to
eukaryotic F-actin. Its polymerization pushes
plasmids to opposite poles of the cell. (part of the
plasmid partitioning locus.)
ParA filament is part of a different partitioning
system that oscillates over the nucleoid and thereby
positions low-copy number plasmids at the midcell
position.
CELL INCLUSIONS:
(a) Glycogen (carbon, energy)
(b) Poly-b-hydroxybutyrate (carbon, energy)
(c) Polyphosphate (volutin, metachromatic
granules)
(d) Cyanophycin (nitrogen, aspartic acid, argining)
(e) Elemental sulfur
(f) magnetosomes.
GAS VACUOLES
CARBOXYSOMES (Rubisco)
Nile Blue staining, a fluorescent stain that binds to polyhydrobutyrate storage granules.
Spirillum volutans with prominent polyphosphate granules (volutin)
Sulfate-reducing
bacteria around
empty shell of
diatom.
(Note transluscent
sulfur granules)
Thiomargarita
Magnetospirillum magnetotacticum containig
magnetosomes (magnetite: Fe3O4)
Gas vesicles in Anabaena.
Vesicles group together as phasebright gas vacuoles (arrows).
Cyanobacterium Microcystis. Gas vesicles are arranged in bundles, here observed in both
longitudinal and cross section.
Dipicolinic acid
Clostridium tetani
Clostridium botulinum.