The Flagellar World

Electron Microscopic Images of Bacterial Flagella and Related Surface Structures

Shin-Ichi Aizawa

• Publisher: Academic Press
• Year: 2013
• Print ISBN: 9780124172340
• eBook ISBN: 9780124172838
• Topic: Scienze biologiche
• Subtopic: Biologia

The Flagellar World is a unique publication. The product of years of research and data collection by the author, this book is a pictorial guide to flagella in a variety of organisms. Each EM image is accompanied by a short description of the system in each organism. These never-before-seen pictures represent a wide variety of flagella, including Legionella pneumophila, Escherichia coli, Pseudomonas aeruginosa, and many others. Researchers in microbiology, immunology, and parasitology will find this a fascinating and useful resource.- A unique publication with many never before seen EM images of flagella- A historical document of years of research on flagella- Fills a specific niche that shows flagella in several varied organisms

Chapter 1

Actinoplanes missouriensis — Swimming Spores with Flagella

Actinoplanes missouriensis is a Gram-positive, soil-inhabiting, filamentous bacterium that characteristically produces spores within a terminal sporangium. Spores are released from sporangia upon contact with water and start swimming by means of flagella. Average number of flagella per spore is 15. The swimming speed of the A. missouriensis cell is as high as 135 μm/s. Actinoplanes spores eventually grow into mycelia and form sporangia again under adverse conditions.

Keywords

Actinoplanes; spores; sporangium; peritrichous flagella; mycelia

Phylum	Actinobacteria
Class	Actinobacteridae
Order	Actinomycetales
Family	Micromonosporaceae
Genus	Actinoplanes
Species	A. missouriensis

Actinoplanes missouriensis is a Gram-positive, soil-inhabiting, filamentous bacterium that characteristically produces spores within a terminal sporangium. Spores are released from sporangia upon contact with water (containing soil extracts) and actively swim by means of flagella, which are completed when the spore is matured. The swimming speed of an A. missouriensis cell is as high as 135 μm/s. Compare this speed with that of the fast swimmer in the sea (Chapter 22).

A. missouriensis flagella grow from one side of the spore rather than from all over, indicating that the spore flagella are not peritrichous, but either polar or lateral despite its round cell body (see Topic: Flagellar position and shape). This kind of flagella arrangement also appears in M. voltae (see Chapter 32).

The basal body is composed of MS rings, but is missing the outer PL rings: a common feature for Gram-positive Firmicutes. The filament is composed of a single kind of flagellin with the MW of 44 kDa.

The genome of A. missouriensis 431 strain consists of a single 8.7-Mbp chromosome. Flagellar genes form a compact cluster at 8,234 bp on the chromosome. Almost all flagella structural genes except those for the rod proteins are found in the compact cluster. There are 3 complete sets of che genes. More than 20 mcp, mlp (mcp-like-protein) genes are scattered all over the chromosome.

The average number of flagella per spore is 15, and the average length of filaments is 1.89 μm, which covers the circumference of the cell body. Release of spores from sporangia starts upon contact with water. 10 minutes after contact, numerous spores had flagella which looked to be forming several layers around the spore. Actinoplanes spores eventually grow into mycelia and form sporangia again under adverse conditions.

Two types of spores were observed in the preparation of PTA-negatively-stained samples: one appears darkly stained, and the other is lightly stained (lower). The latter appears to be a membranous empty sheath with a large crevice in the middle of the body, indicating that flagellar assembly has already been completed in the sheath. Flagellated spores hatch and leave an empty sheath behind.

Strains were provided by Yasuo Ohnishi of the University of Tokyo, Tokyo, Japan.

The project was carried out by Moon Sun Jang and Kaoru Uchida.

Chapter 2

Aliivibrio fischeri — Light-Organ Symbiont in the Bobtail Squid

Aliivibrio (formerly Vibrio) fischeri is a Gram-negative, marine bacterium. A. fischeri has a symbiotic relationship with the bobtail squid (Euprymna scolopes), in which it produces bioluminescence in the host’s luminous organ. Each cell possesses several polar flagella. The filament is composed of six flagellins (FlaA–F). Flagellar genes form one of the most compact clusters on the genome.

Keywords

Vibrio fischeri; polar flagella; bioluminescence; the bobtail squid; lux operon

Phylum	Proteobacteria
Class	Gammaproteobacteria
Order	Vibrionales
Family	Vibrionaceae
Genus	Aliivibrio
Species	A. fischeri

Aliivibrio (formerly Vibrio) fischeri is a Gram-negative, marine bacterium. A. fischeri has a symbiotic relationship with the bobtail squid (Euprymna scolopes), in which it produces bioluminescence from the host’s luminous organ. The light emission is cont...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Preface
• Introduction
• Chapter examples
• Chapter 1. Actinoplanes missouriensis — Swimming Spores with Flagella
• Chapter 2. Aliivibrio fischeri — Light-Organ Symbiont in the Bobtail Squid
• Chapter 3. Azospirillum brasilense — A Bushy Hook of the Polar Flagellum
• Chapter 4. Bacillus subtilis — The Representative of Gram-Positive Bacteria
• Topic 1: Gene Regulation
• Topic 2: Gene Arrangement
• Topic 3: Mot Proteins
• Topic 4: Flagellin size
• Topic 5: Flagella and Pathogenicity
• Topic 6: Flagellar Position and Shape
• Topic 7: History of Salmonella SJW Strains
• Topic 8: Hook length
• Topic 9: Multiple Flagellins
• Appendix
• References
• Index