Chapter 11 The Prokaryotes: Domains of Bacteria and Archaea Lectures prepared by Christine L. Case © 2013 Pearson Education, Inc. Lectures prepared by Christine L. Case Copyright © 2013 Pearson Education, Inc. © 2013 Pearson Education, Inc. The Prokaryotes © 2013 Pearson Education, Inc. Domain Bacteria  Proteobacteria  From the mythical Greek god Proteus, who could assume many shapes  Gram-negative  Chemoheterotrophic © 2013 Pearson Education, Inc. The Alphaproteobacteria Learning Objective 11-1 Differentiate the alphaproteobacteria described in this chapter by drawing a dichotomous key. © 2013 Pearson Education, Inc. The Alphaproteobacteria  Pelagibacter ubique  Discovered by FISH technique  20% of prokaryotes in oceans  0.5% of all prokaryotes  1354 genes © 2013 Pearson Education, Inc. The Alphaproteobacteria  Human pathogens  Bartonella − B. henselae: cat-scratch disease  Brucella: brucellosis  Ehrlichia: tickborne © 2013 Pearson Education, Inc. The Alphaproteobacteria  Obligate intracellular parasites  Ehrlichia: tickborne, ehrlichiosis  Rickettsia: arthropod-borne, spotted fevers − R. prowazekii: epidemic typhus − R. typhi: endemic murine typhus − R. rickettsii: Rocky Mountain spotted fever © 2013 Pearson Education, Inc. Figure 11.1 Rickettsias. Slime layer Chicken Scattered embryo cell rickettsias Nucleus Masses of rickettsias in nucleus A rickettsial cell that has Rickettsias grow only within a host cell, just been released from a such as the chicken embryo cell shown host cell here. Note the scattered rickettsias within the cell and the compact masses of rickettsias in the cell nucleus. © 2013 Pearson Education, Inc. The Alphaproteobacteria  Wolbachia: live in insects and other animals © 2013 Pearson Education, Inc.