Bacterial recombination is characterized by DNA transfer from one “donor” organism to a “recipient” organism, which allows the bacteria to express new proteins. This may give the bacteria additional functionality such as antibiotic resistance which in turn can be of selective advantage!

The 3 main ways of bacterial recombination include transformation, conjugation and transduction.

Conjugation is when genetic material is transferred from one bacterium to another by direct contact. During conjugation, one bacterium acts as a donor of the genetic material, and the other serves as the recipient. One could even say that this is a form of bacterial sex as it involves the exchange of genetic material. Without any resulting babies of course!

Conjugation is carried out in 4 main steps.

1. The process is initiated by the donor cell producing a pilus, which is a thin, tubelike structure, that the donor uses to contact the recipient.
2. The pilus attaches to the recipient and draws the 2 bacteria together. Typically, the genetic material is in the form of a plasmid which is a small circular piece of DNA.
3. The mobile plasmid is nicked and a single strand of DNA is then transferred to the recipient cell.
4. Finally, both cells synthesize a complementary strand to produce a double stranded circular plasmid and also reproduce pili; both cells are now viable donors for the F-factor.

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