Effect of bacterial growth rate on bacteriophage population growth rate

Abstract

It is important to understand how physiological state of the host influence propagation of bacteriophages (phages), due to the potential higher phage production needs in the future. In our study, we tried to elucidate the effect of bacterial growth rate on adsorption constant (δ), latent period (L), burst size (b), and bacteriophage population growth rate (λ). As a model system, a well‐studied phage T4 and Escherichia coli K‐12 as a host was used. Bacteria were grown in a continuous culture operating at dilution rates in the range between 0.06 and 0.98 hr−1. It was found that the burst size increases linearly from 8 PFU·cell−1 to 89 PFU·cell−1 with increase in bacteria growth rate. On the other hand, adsorption constant and latent period were both decreasing from 2.6∙10‐9 ml·min−1 and 80 min to reach limiting values of 0.5 × 10‐9 ml·min−1 and 27 min at higher growth rates, respectively. Both trends were mathematically described with Michaelis–Menten based type of equation and reasons for such form are discussed. By applying selected equations, a mathematical equation for prediction of bacteriophage population growth rate as a function of dilution rate was derived, reaching values around 8 hr−1 at highest dilution rate. Interestingly, almost identical description can be obtained using much simpler Monod type equation and possible reasons for this finding are discussed.

Identification and Characterization of New Bacteriophages to Control Multidrug-Resistant Pseudomonas aeruginosa Biofilm on Endotracheal Tubes

“…Nonetheless, comparing burst sizes with bacteriophages with a similar genome, we noticed that all bacteriophages produced lower burst sizes ( Guo et al, 2019 ; Yuan et al, 2019 ). The reduction observed here could be explained by differences in bacterial growth rates since the burst size increases linearly with bacterial growth rate ( Nabergoj et al, 2018 ). Adsorption and latent period also vary with bacterial growth rate, decreasing at higher growth rates.…”

High Throughput Manufacturing of Bacteriophages Using Continuous Stirred Tank Bioreactors Connected in Series to Ensure Optimum Host Bacteria Physiology for Phage Production

“…In this study, we used a completely synthetic medium with glucose as the only sugar source as the limiting substrate. Previous studies using chemostats to investigate the effect of host physiology have used complex ill-defined media where it was unclear which limiting factor affected the host organism growth rate, and therefore influenced the parameters affecting phage amplification [ 39 ]. Using the value of the maximum specific growth rate (µ m = 1 hr −1 ) results in a doubling time of ~42 min.…”

Nitrogen sourcing during viral infection of marine cyanobacteria

“…In addition to their influence on population dynamics and host evolution, they also play important roles in the biogeochemistry of microbial ecosystems, particularly with regard to nutrient cycling (1)(2)(3). Viruses essentially compete with microbial cells for the nutrients that limit biological production, and viral productivity has been found to correlate with environmental nutrient availability in a variety of settings (4,5). There are 2 basic sources for the nutrients, such as N and phosphorus (P), that viruses need for replication: (1) breakdown and recycling of host cell biomass, and (2) de novo biosynthesis using host metabolic machinery and nutrients derived from the extracellular environment.…”