Chapter 7

• Crown gall. Photograph of a crown gall

  tumor (arrow) on a tobacco plant caused

  by Agrobacterium tumefaciens.
• Soybean root nodules. The nodules

  developed from infection by

  Bradyrhizobium japonicum
• Ruminant animals. Microorganisms in the rumen of the cow convert cellulose from grass into fatty acids that can be used by the animal.
• Glycocalyx: An outer viscous covering of fibers extending from the

  bacterium

  • Usually a viscous polysaccharide or polypeptide slime

  • Actual production of a glycocalyx often depends on

  environmental conditions
• Capsule: organized and is attached to the cell wall
• Slime layer: not organized is loosely attached to the cell wall
• S layer: mostly common in archaea and is composed of proteins
• Flagella: gives motility to the cell

  • Gram positive: thick peptidoglycan layer
  • Gram negative: thin peptidoglycan layer
• Monotrichous: attached to one pole of the cell
• Amphitrichous: attached to two poles of the cell
• Peritrichous: bundles attached to both poles
• Fimbriae: gives adherence and attachment to surfaces and are thin layers
• Pili: has a fertility pili present, which can transfer genetic material from one cell to another. Also responsible for adherence
• Teichoic acid: stabilizes the structure
• Periplasm: space between cytoplasmic membrane and outer membrane
• Mycoplasmas

  • Absence of cell wall Sterol and

  lipoglycans in the

  cytoplasmic

  membrane
• Bacteria: lipid bilayer, ester-linked lipids, straight chain fatty acids
• Archaea: lipid monolayer, ether-linked lipids, branched fatty acids