The use of phage display as an innovative approach in environmental science.

摘要

This PhD-study investigated, the potential of phage display in environmental research. Phages are viruses that use their host bacterial cells as factories for their own replication and have the ability to display peptides or proteins on their surfaces. This technology is called phage display. Phage display can be used as a powerful tool to screen for peptides and proteins with affinity for all kinds of targets, ranging from small molecules to proteins and even cells. This selection can be performed by using phage libraries consisting of a high number of different phages (106--109 ), each displaying a different peptide or protein on its surface. Among the huge number of phages in these phage libraries, the ones with high affinity and specificity for a target can be isolated via an affinity selection procedure. Although phage display had already shown its potential in many research areas, its use in environmental research was scarce. During this PhD-study, the potential of phage display in environmental research is investigated, for two applications. The first application is as a screening tool for cellular targets of chemical compounds, which will provide a better insight into the mechanism of action of chemical compounds. This application was demonstrated in this PhD-study by determining the cellular targets of a metal (Nickel), Estradiol and Bisphenol A. The second application is the use of specific binding phages as innovative biorecognition elements in biosensors for environmental monitoring. The excellent characteristics of phages, such as their high affinity and specificity, the fast, cheap and animal-friendly manufacturing process with low batch-to-batch variations and their high stability, makes them very interesting alternatives to antibodies, which are the traditionally used recognition elements in biosensors. In this PhD-study, phages were specifically selected for targets such as polychlorinated biphenyl (PCB) and chloramphenicol acetyl transferase (CAT), which can be used to develop biosensors for these targets. Thus, this PhD-study has brought to light the immense potential of the phage display approach in environmental research.