Bacterial Motility Hugh B. Fackrell
2 8/5/2015 Presentation Outline l Bacterial Flagella l Location l Function l Structure l Bacterial vs eukaryotic flagella
3 8/5/2015 Flagellum vs Pilus Pilus Flagellum
4 8/5/2015 Pilus (fimbriae) l An appendage of the bacterial cell used for transfer of genetic information l Plural pili
5 8/5/2015 Pili Transfer Plasmids
6 8/5/2015 Bacterial Flagellum l A thin appendage arising from one or more locations on the surface of the cell wall l Cellular locomotion l Moves cell along gradients e.g. glucose
7 8/5/2015 Types of Motility l Flagellated –Flagellum- l coordinated movement l tumbling movement –Axial filament- spirochetes l Gliding- no visible organelles
8 8/5/2015 Location l Polar l Subpolar l Lateral l Lophotrichous l Amphitrichous l Peritrichous l Periplasmic
9 8/5/2015 Polar Flagellum
10 8/5/2015 Lophotrichous Flagella Spirillum volutns two or more flagella at the end of the microbe Photographs show growth of flagella during replication
11 8/5/2015 Amphitrichous Flagella l Tufts of flagella at BOTH ends of the microbe
12 8/5/2015 Peritrichous Flagella
13 8/5/2015 Flagellar tufts
14 8/5/2015 Flagellar tufts
15 8/5/2015 Spirochetes have Periplasmic Flagella l Periplasmic flagella are also called the axial filament
16 8/5/2015 Axial filaments
17 8/5/2015 Bacterial Flagellum
18 8/5/2015 Rings of Gram Negative Flagellum l M: cell Membrane l P: Peptidoglycan l L: Outer Layer l S: Spacer
19 8/5/2015 Flagellar Structure (details)
20 8/5/2015 Prokaryotic Flagellum
21 8/5/2015 Flagellar Structures
22 8/5/2015 Assembly of Flagellum
23 8/5/2015 Demonstration of Chemotaxis l Capillary tube contains attractant chemical l Attractants: –Glucose,Maltose, Alanine l Repellents: –Indole, H+, OH-, fatty acids
24 8/5/2015 Flagellar Rotation l Clockwise: Tumbling l Counterclockwise: coordinated l Alternate between two rotations
25 8/5/2015 “Run & Tumble” motility
26 8/5/2015 Regulation of Flagellar Movement
27 8/5/2015 Movement of Flagella l Whip l Egg beater