Middelboe M
Marine Biological Laboratory, University of Copenhagen, Strandpromenaden 5, DK-3000 Helsingør, Denmark
Microb Ecol. 2000 Aug;40(2):114-124. doi: 10.1007/s002480000050.
The dynamics of a marine virus-host system were investigated at different steady state growth rates in chemostat cultures and the data were analyzed using a simple model. The virus-host interactions showed strong dependence on host cell growth rate. The duration of the infection cycle and the virus burst size were found to depend on bacterial growth rate, and the rate of cell lysis and virus production were positively correlated with steady state growth rate in the cultures (r(2) > 0.96, p < 0.05). At bacterial growth rates of 0.02 to 0.10 h(-1) in the chemostats the virus burst size increased from 12 +/- 4 to 56 +/- 4, and the latent period decreased from 2.0 to 1.7 h. Resistant clones of the host strain were present in the cultures from the beginning of the experiment and replaced the sensitive host cells following viral lysis in the cultures. Regrowth of resistant cells correlated significantly (r(2) = 1.000, p < 0.02) with the lysis rate of sensitive cells, indicating that release of viral lysates stimulated growth of the non-infected, resistant cells. The constructed model was suitable for simulating the observed dynamics of the sensitive host cells, viruses and resistant clones in the cultures. The model was therefore used in an attempt to predict the dynamics of this virus-host interaction in a natural marine environment during a certain set of growth conditions. The simulation indicated that a steady state relationship between the specific viruses and sensitive and resistant bacterial clones may occur at densities that are reasonable to assume for natural environments. The study demonstrates that basic characterization and modeling of specific virus-host interactions may improve our understanding of the behavior of bacteria and viruses in natural systems.
在恒化器培养中，研究了海洋病毒 - 宿主系统在不同稳态生长速率下的动态变化，并使用一个简单模型对数据进行了分析。病毒与宿主的相互作用表现出对宿主细胞生长速率的强烈依赖性。发现感染周期的持续时间和病毒爆发量取决于细菌生长速率，并且细胞裂解速率和病毒产生速率与培养物中的稳态生长速率呈正相关（r² > 0.96，p < 0.05）。在恒化器中细菌生长速率为0.02至0.10 h⁻¹时，病毒爆发量从12 ± 4增加到56 ± 4，潜伏期从2.0小时减少到1.7小时。从实验开始，宿主菌株的抗性克隆就存在于培养物中，并在培养物中病毒裂解后取代了敏感宿主细胞。抗性细胞的再生长与敏感细胞的裂解速率显著相关（r² = 1.000，p < 0.02），表明病毒裂解物的释放刺激了未感染的抗性细胞的生长。构建的模型适用于模拟培养物中敏感宿主细胞、病毒和抗性克隆的观察到的动态变化。因此，该模型被用于尝试预测在特定一组生长条件下自然海洋环境中这种病毒 - 宿主相互作用 的动态变化。模拟表明，在自然环境中合理假设的密度下，特定病毒与敏感和抗性细菌克隆之间可能会出现稳态关系。该研究表明，特定病毒 - 宿主相互作用的基本特征描述和建模可能会提高我们对自然系统中细菌和病毒行为的理解。
