Scale-Up and Bioprocessing of Phages

Abstract

A profusion of new applications for phage technologies has been developed within the last few years, stimulating investigations into the large-scale production of different phages. Applications such as antibiotic replacement, phages as gene therapy vectors, phages as vaccines, diagnostics using filamentous phages and novel optical applications such as the phage laser may need grams to kilogrammes of phage in the future. However, many of the techniques that are used for the growth and purification of bacteriophage at small scale are not transferable to large-scale production facilities of phage in industrial processes. In this chapter, the stages of production that need to be carried out at scale are examined for the efficient large-scale fermentation of the filamentous phage M13 and the Siphoviridae phage lambda (λ). A number of parameters are discussed: the multiplicity of infection (MOI) of phage to host cells, the impact of agitation on the initial infection stages, the co-growth with phage rather than static attachment, the use of engineered host cells expressing nuclease, the optimisation of both the quantity and the physiology of the E. coli inoculum and phage precipitation methods.

Optimization of Escherichia coli Bacteriophages Production

“…With the increment in incubation time resulting in a corresponding increase in phage production, probably due to a characteristic physiological state of the cells growing [40,42].Agitation is a crucial aspect of phage production. Agitation plays a role in the aeration dynamics and oxygen availability, increases the probability of contact between the phage particles and the host cells, leading to an irreversible attachment and beginning the infection process [43,44]. However, if the agitation is too intense, the phage tails can be broken while the absorption process inhibits the infectious process [45].Temperature is less important individually but shows good interactions with other factors, so it should be taken in an optimized condition.…”

Medical Device-Associated Healthcare Infections: Sterilization and the Potential of Novel Biological Approaches to Ensure Patient Safety

“…The bacterial expression system may become resistant to phage infection, or the phage structure may change from the desired structure [ 110 ]. The bacterial nucleic acid and protein content post-cell lysis impacts the downstream processing of phages and peptides from bioreactors and large-scale production [ 111 ]. The presence of bacterial nucleic acids, proteins, enzymes, and LPS toxins in the final product impacts biocompatibility [ 111 ].…”

“…The bacterial nucleic acid and protein content post-cell lysis impacts the downstream processing of phages and peptides from bioreactors and large-scale production [ 111 ]. The presence of bacterial nucleic acids, proteins, enzymes, and LPS toxins in the final product impacts biocompatibility [ 111 ]. For IV phage formulation, such impurities are not acceptable, particularly LPS toxin, which is associated with fever, leukopenia, leukocytosis, and fatal sepsis [ 107 ].…”