MicroBiology-Draft/Sample

the plasma membrane and the cell wall, feeding on the host’s proteins and polysaccharides. The infection is lethal for
the host cells.

Another type of Deltaproteobacteria, myxobacteria, lives in the soil, scavenging inorganic compounds. Motile and
highly social, they interact with other bacteria within and outside their own group. They can form multicellular,
macroscopic “fruiting bodies” (Figure 4.11), structures that are still being studied by biologists and bacterial
ecologists.[11]These bacteria can also form metabolically inactive myxospores.

Figure 4.11 Myxobacteria form fruiting bodies. (credit: modification of work by Michiel Vos)

Table 4.5summarizes the characteristics of several important genera of Deltaproteobacteria.

Class Deltaproteobacteria

Genus Microscopic Morphology Unique characteristics

Bdellovibrio Gram-negative, comma-

shaped rod

Obligate aerobes; motile; parasitic (infecting other

bacteria)

Desulfovibrio

(formerly

Desufuromonas)

Gram-negative, comma-

shaped rod

Reduce sulfur; can be used for removal of toxic and

radioactive waste

Myxobacterium Gram-negative, coccoid

bacteria forming colonies

(swarms)

Live in soil; can move by gliding; used as a model

organism for studies of intercellular communication

(signaling)

Table 4.5

1. What type of Deltaproteobacteria forms fruiting bodies?


2. H. Reichenbach. “Myxobacteria, Producers of Novel Bioactive Substances.”Journal of Industrial Microbiology & Biotechnology27 no.
   3 (2001):149–156.

Chapter 4 | Prokaryotic Diversity 155