Date of Award


Document Type

Master Thesis

Degree Name

Masters of Science (Research)


Biological Sciences

First Advisor

Prof. Aidan Coffey


Bacteriophage (phage) are the most abundant biological entities on earth and were first discovered by d’Herelle in 1917. They are found wherever their hosts live and, like all viruses they do not have the ability to make their own protein. Therefore, in order to reproduce, phage must invade and infect bacterial cells. This project focused on the optimisation of Ion Exchange Chromatography purification protocols for a staphylococcal peptidoglycan degrading hydrolase enzyme (CHAPk). The project objective was to obtain the greatest yield of enzyme from the growth of the E.coU XL 1-Blue expression system into which the vector pQE60 was previously cloned. It details the many trials of the various parameters entailed in ion exchange chromatography. The quantification of the enzyme produced (CHAPk) was investigated, following this, the activity of the enzyme produced was tested against Gram positive staphylococcal bacteria. Optimisation trials using various parameters covering all aspects of purification were conducted during this project. The result of the investigation yielded 2 ml of enzyme stock with a concentration of 4.4 mg/ml. The activity of the purified enzyme was tested against a Gram positive DSM 9385 strain oiStaphylococcus aureus.

Access Level