Question

Describe a technique used to increase the concentration of a TOL plasmid.

Answer 1

TOL plasmids were a major group of catabolic plasmids among the bacterial strains isolated from the oil-contaminated rhizosphere of Galega orientalis. TOL plasmid encodes the genes for the enzymes for the conversion of the aromatic hydrocarbons to their corresponding carboxylic acids.

The concentration of the TOL plasmid can be increased by several methods in a bacterial cell:

• Through the conjugation method between two adjacent bacterial cells: TOL plasmids were recovered from the Pseudomonas putida which is a bacterial strain which contains the enzymes involved in toluene degradation. The in vitro conjugation process is made to happen in between Pseudomonas and Rhizobium as an example when they are in a close proximity. Bacterial conjugation is a way by which a bacterial cell transfers genetic material to another bacterial cell. The genetic material that is transferred through bacterial conjugation is a small plasmid and here is the transfered plasmid is TOL plasmid.
• Through prokaryotic Transcriptional Factors: The prokaryotic transcriptional factor (TFs) gets binded with the target sequence and increases the transcriptional output. Transcriptional factors are proteins that regulate the transcription of genes—that is, their copying into RNA, on the way to making a protein. Many TFs are known to facilitate transcription at hundreds of different promoters. Signal molecules can influence activation by TFs by covalently binding or modifying their functional domains. It is even possible for a TF to respond to a physical signal, such as red or far-red light.

By using these techniques, the concentration of the TOL plasmid can be increased insie the bacterial cell.