Phages and biotechnologies

Phages, or bacteriophages, are viruses of prokaryotes. They are biological entities that need to hijack their hosts' cellular machinery in order to complete their replication cycle. Phages are intimately linked to the ecophysiological characteristics of their hosts. As a result, they have developed different strategies over the course of their evolution to maintain the dynamic host/virus equilibrium necessary for their survival. This adaptive potential has proved particularly inventive and interesting from a biotechnological point of view. From their earliest descriptions, phages have found biotechnological applications in key industrial sectors such as agronomy, agri-food and biomedical, in the form of alternative strategies to biocides for both biocontrol and curative purposes. They have also been exploited as platforms for bioprocesses (e.g. phage display) or as sources of innovative biomolecules (e.g. enzymes). However, after a century, the role of phages in biotechnology is still limited in relation to their real potential. There are many reasons for this. For example, when it comes to using phages as health tools (phage therapy or biocontrol), the "biological" nature of phages is both their great strength and their greatest weakness. An undeniable advantage over a chemical biocide is their self-replicating nature, which requires no dose/response effect. Nevertheless, the effectiveness of the approach requires perfect control of the propagation process, which is far more complex than in the context of using a purely chemical agent. This article begins by explaining the biotechnological potential of phages, focusing on their biological and ecological characteristics. This is followed by a look at concrete examples of biotechnological applications in various industrial sectors.