Beckett Stephen J, Weitz Joshua S
School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States.
School of Physics, Georgia Institute of Technology, Atlanta, GA, United States.
Front Microbiol. 2018 Sep 3;9:1850. doi: 10.3389/fmicb.2018.01850. eCollection 2018.
Infection and lysis of phytoplankton by viruses affects population dynamics and nutrient cycles within oceanic microbial communities. However, estimating the quantitative rates of viral-induced lysis remains challenging . The modified dilution method is the most commonly utilized empirical approach to estimate virus-induced killing rates of phytoplankton. The lysis rate estimates of the modified dilution method are based on models which assume virus-host interactions can be represented by a single virus and a single host population with homogeneous life-history traits. Here, using modeling approaches, we examine the robustness of the modified dilution method in multi-strain, complex communities. We assume that strains differ in their life history traits, including growth rates (of hosts) and lysis rates (by viruses). We show that trait differences affect resulting experimental dynamics such that lysis rates measured using the modified dilution method may be driven by the fastest replicating strains; which are not necessarily the most abundant . We discuss the implications of using the modified dilution method and alternative dilution-based approaches for estimating viral-induced lysis rates in marine microbial communities.
病毒对浮游植物的感染和裂解会影响海洋微生物群落中的种群动态和营养循环。然而，估算病毒诱导裂解的定量速率仍然具有挑战性。改良稀释法是估算病毒诱导浮游植物杀灭率最常用的经验方法。改良稀释法的裂解率估算基于一些模型，这些模型假设病毒-宿主相互作用可以由具有均匀生活史特征的单一病毒和单一宿主种群来表示。在此，我们使用建模方法研究改良稀释法在多菌株复杂群落中的稳健性。我们假设菌株在其生活史特征上存在差异，包括（宿主的）生长速率和（被病毒感染后的）裂解速率。我们表明，特征差异会影响实验结果动态，使得使用改良稀释法测得的裂解速率可能由复制最快的菌株驱动；而这些菌株不一定是数量最多的。我们讨论了使用改良稀释法以及其他基于稀释的方法来估算海洋微生物群落中病毒诱导裂解率的意义。
