lysogeny broth

Examples of lysogeny broth in the following topics:

• Culture Media

  • The most common growth media nutrient broths (liquid nutrient medium) or LB medium (Lysogeny Broth) are liquid.

• Plasmids and Lysogeny

  • Both plasmids and lysogeny are used by bacteria and viruses to ensure transfer of genes and nucleic acids for viral reproduction.
  • Lysogeny is the process by which a bacteriophageintegrates its nucleic acids into a host bacterium's genome.
  • Lysogeny is utilized by viruses to ensure the maintenance of viral nucleic acids within the genome of the bacterium host.
  • Lysogeny is one of two major methods of viral reproduction utilized by viruses.
  • An example of a virus which can promote the transformation of bacterium from a nontoxic to toxic strain via lysogeny is the CTXφ virus.

• Temperate Bacteriophages: Lambda and P1

  • With phage the term virulent is often used as an antonym to temperate, but more strictly a virulent phage is one that has lost its ability to display lysogeny through mutation, rather than a phage lineage with no genetic potential to ever display lysogeny (which more properly would be described as an obligately lytic phage).
  • In lysogeny, P1 can exist within a bacterial cell as a circular DNA, in that it exists by replicating as if it were a plasmid and does not cause cell death.
  • During lysogeny, new phage particles are not produced.
  • A unique feature of phage P1 is that during lysogeny its genome is not incorporated into the bacterial chromosome, as is commonly observed during lysogeny of other bacteriophage.
  • This virus is temperate and may reside within the genome of its host through lysogeny.

• History of Microbiology: Hooke, van Leeuwenhoek, and Cohn

  • Lazzaro Spallanzani (1729–1799) found that boiling broth would sterilise it and kill any microorganisms in it.
  • He also found that new microorganisms could settle only in a broth if the broth was exposed to the air.
  • By boiling the broth beforehand, Pasteur ensured that no microorganisms survived within the broths at the beginning of his experiment.
  • Nothing grew in the broths in the course of Pasteur's experiment.
  • This meant that the living organisms that grew in such broths came from outside, as spores on dust, rather than spontaneously generated within the broth.

• Pasteur and Spontaneous Generation

  • In summary, Pasteur boiled a meat broth in a flask that had a long neck that curved downward, like a goose.
  • The idea was that the bend in the neck prevented falling particles from reaching the broth, while still allowing the free flow of air.
  • When the flask was turned so that particles could fall down the bends, the broth quickly became clouded .
  • In detail, Pasteur exposed boiled broths to air in vessels that contained a filter to prevent all particles from passing through to the growth medium, and even in vessels with no filter at all, with air being admitted via a long tortuous tube that would not allow dust particles to pass.
  • Nothing grew in the broths unless the flasks were broken open, showing that the living organisms that grew in such broths came from outside, as spores on dust, rather than spontaneously generated within the broth.

• The Lytic and Lysogenic Cycles of Bacteriophages

  • Those phages able to undergo lysogeny are known as temperate phages.
  • Even though there are similarities between lysogeny and latency, the term lysogenic cycle is usually reserved to describe bacteriophages.

• Pure Culture

  • Another method of bacterial culture is liquid culture, in which the desired bacteria are suspended in liquid broth, a nutrient medium.
  • The experimenter would inoculate liquid broth with bacteria and let it grow overnight (they may use a shaker for uniform growth).

• Tissue Culture of Animal Viruses

  • Viruses cannot be grown in standard microbiological broths or on agar plates, instead they have be to cultured inside suitable host cells.

• Complex and Synthetic Media

  • Luria Broth as shown here is made with yeast extract, as yeast extract is not completely chemically defined Luria Broth is therefore an undefined media.By Lilly_M [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0-2.5-2.0-1.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

• Minimal Inhibitory Concentration (MIC)

  • MICs can be determined on plates of solid growth medium (called agar, shown in the "Kirby-Bauer Disk Susceptibility Test" atom) or broth dilution methods (in liquid growth media, shown in ) after a pure culture is isolated.
  • For example, to identify the MIC via broth dilution, identical doses of bacteria are cultured in wells of liquid media containing progressively lower concentrations of the drug.