Microbiology 1010 – Lecture Notes
Allows them to stick to the environment
Pellicles = Protein in protective barrier against other materials that cover the bacteria
o Filamentous protein structures (Figure 2.34)
o Typically longer than fimbriae
o Assist in surface attachment
o Facilitate genetic exchange between cells (conjugation)
o Type IV pili involved in twitching motility
Allows them to them to spread instructions very quickly within a population of unrelated
bacteria (different genius and different species)
Gram neg. (twitching motility – extend or take out some of the proteins with the pili structure to make
it shorter or longer)
Cell Inclusion Bodies
Visible aggregates in cytoplasm
Carbon storage polymers
o Poly-β-hydroxybutyric acid (PHB): lipid
Glycogen: glucose polymer
Polyphosphates: accumulations of inorganic phosphate
Sulfur globules: composed of elemental sulfur
Magnetosomes: magnetic storage inclusions
Storage granules that they can tap into them if his needs arise.
Carbon storage polymers
Polymer of glucose
Polyphosphate granules – volutin
Storage of phosphate and energy
Sulfur gStorage of sulfur used in energy generation.
Fats are rich in energy
Inorganic inclusions – Do not have carbon but instead will store other materials.
Need sulfur in our amino acids and is used for energy or for amino acid production.
Magnetic inclusions - Magnetosomes
o Intracellular granules of Oe4or FeS4
49 Microbiology 1010 – Lecture Notes
Gives thAllows it to orient itself in a magnetic field
o Bacteria migrate along Earth’s magnetic field – magnetotaxis
Allows the cell to align itself in a magnetic field so it can move along the field from point A to point B.
Confer buoyancy in planktonic cells
Spindle-shaped, gas-filled structures made of protein
Function by decreasing cell density
Impermeable to water
o Cyanobacteria form “blooms”
Require light energy for photosynthesis.
Can’t confer a buoyant, they don’t have the same light exposure so then photosynthesis.
o Highly differentiated cells resistant to heat, harsh chemicals, and radiation
o “Dormant” stage of bacterial life cycle (Figure 2.43)
o Ideal for dispersal via wind, water, or animal gut
Gram positive only (only some gram + though – only some genius and species)
But all gram neg. have LPS.
Produced only by some Gram positives
o Ex. Bacillus sp. – aerobic Gram + rods
Ex. Clostridium sp. – anaerobic Gram + rods
Vegetative cell– capable of normal growth
Endospore – dormant cell, formed inside of a mother cell
o Triggered by lack of nutrients
o Takes about 8 - 10 hours
50 Microbiology 1010 – Lecture Notes
Metabolism is essentially zero.
Triggered by lack of nutrients or boiling water etc.
Protective features of the Endospore
Spore coat and cortex – protect against chemicals, enzymes, physical damage,
Two membranes – permeability barriers against chemicals
Dehydrated – protects against heat
Ca-dipicolinic acid and SASPs
Protect against DNA damage
Endospores can resist:
Boiling for hours
UV, g radiation
DNA is the instructions to develop the things of a normal cell again.
Reason it has two membranes is because it starts off as a cell
that is engulfed by the mother cell.
Dehydrated because heat affects you a lo