Specific growth rate and multiplicity of infection affect high-cell-density fermentation with bacteriophage M13 for ssDNA production

The bacteriophage M13 has found frequent applications in nanobiotechnology due to its chemically and genetically tunable protein surface and its ability to self-assemble into colloidal membranes. Additionally, its single-stranded (ss) genome is commonly used as scaffold for DNA origami. Despite the manifold uses of M13, upstream production methods for phage and scaffold ssDNA are underexamined with respect to future industrial usage. Here, the high-cell-density phage production with Escherichia coli as host organism was studied in respect of medium composition, infection time, multiplicity of infection, and specific growth rate. The specific growth rate and the multiplicity of infection were identified as the crucial state variables that influence phage amplification rate on one hand and the concentration of produced ssDNA on the other hand. Using a growth rate of 0.15 h⁻¹ and a multiplicity of infection of 0.05 pfu cfu⁻¹ in the fed-batch production process, the concentration of pure isolated M13 ssDNA usable for scaffolded DNA origami could be enhanced by 54% to 590 mg L⁻¹. Thus, our results help enabling M13 production for industrial uses in nanobiotechnology. Biotechnol. Bioeng. 2017;114: 777–784.