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Created page with 'thumb|right|100px|Binary fission- copyright J W Schmidt Replication normally occurs by binary fission and ranges from every 20 mins (e.g. Staphylococ…'
[[Image:Binary fission.png|thumb|right|100px|Binary fission- copyright J W Schmidt]]
Replication normally occurs by binary fission and ranges from every 20 mins (e.g. Staphylococci) to 2 weeks (e.g. leprosy bacillus)
*Variation can occur either by mutations in their DNA, or by ''lateral gene transfer'':
**Transformation- small, naked pieces of DNA are directly transferred between bacteria, e.g. ''S pneumoniae''
**Transduction- viruses known as bacteriophages transfer the DNA, many genes encoding toxins are transferred this way[[Image:Conjugative plasmids.png|thumb|right|100px|Conjugative plasmids- copyright Magnus Manske]]
**Conjugation- DNA is transferred in the form of plasmids, genes encoding antibiotic resistance are typically transferred this way.
Typical requirements of bacteria
*Atmospheric requirements:
**Obligate aerobe- e.g. ''B. bronchoseptica''
**Facultative (optional) anaerobe-e.g. ''E. coli''
**Obligate anaerobe- e.g. ''F. necrophorum''
**Microaerophil- e.g. ''C. jejuni''
**Aerotolerant- e.g. ''S. dysgalactiae''
*pH- most pathogens require a neutral pH, although some need acidic/alkali environments:
**Acidophilic- Lactobacillus
**Alkophilic- Vibrio
Replication of ''E. coli'' [http://www.cellsalive.com/qtmovs/ecoli_mov.htm]
[[Category:Bacteria]]
Replication normally occurs by binary fission and ranges from every 20 mins (e.g. Staphylococci) to 2 weeks (e.g. leprosy bacillus)
*Variation can occur either by mutations in their DNA, or by ''lateral gene transfer'':
**Transformation- small, naked pieces of DNA are directly transferred between bacteria, e.g. ''S pneumoniae''
**Transduction- viruses known as bacteriophages transfer the DNA, many genes encoding toxins are transferred this way[[Image:Conjugative plasmids.png|thumb|right|100px|Conjugative plasmids- copyright Magnus Manske]]
**Conjugation- DNA is transferred in the form of plasmids, genes encoding antibiotic resistance are typically transferred this way.
Typical requirements of bacteria
*Atmospheric requirements:
**Obligate aerobe- e.g. ''B. bronchoseptica''
**Facultative (optional) anaerobe-e.g. ''E. coli''
**Obligate anaerobe- e.g. ''F. necrophorum''
**Microaerophil- e.g. ''C. jejuni''
**Aerotolerant- e.g. ''S. dysgalactiae''
*pH- most pathogens require a neutral pH, although some need acidic/alkali environments:
**Acidophilic- Lactobacillus
**Alkophilic- Vibrio
Replication of ''E. coli'' [http://www.cellsalive.com/qtmovs/ecoli_mov.htm]
[[Category:Bacteria]]