VIRAL MORTALITY OF MARINE-BACTERIA AND CYANOBACTERIA
VIRAL MORTALITY OF MARINE-BACTERIA AND CYANOBACTERIA
复制标题
DOI：
10.1038/343060a0
复制
发表时间：
1990-01-04
期刊：
影响因子：
64.8
通讯作者：
FUHRMAN, JA
中科院分区：
文献类型：
--
作者：
PROCTOR, LM;FUHRMAN, JA
尽管蓝藻在全球初级生产力中发挥着重要作用，异养细菌在海洋有机物的消耗中也发挥着重要作用，但人们对它们（尤其是蓝藻）死亡的原因却知之甚少。通常认为死亡是由于原生动物放牧3,4而不是病毒感染造成的，这可能是因为自然界中噬菌体和宿主的丰度被认为很低5。此前，要么通过噬菌斑测定发现极少数海洋噬菌体6-9，要么通过透射电子显微镜简单地观察10-12或计数13,14病毒，假设“噬菌体外观”形式是局部活跃的噬菌体。在这里，我们不仅报告了海洋中的高病毒丰度，还报告了溶解感染最后不可逆阶段的细菌和蓝细菌的数量。后者的计数对于评估死亡率是必要的，因为观察到的游离病毒的来源、宿主、活力和年龄尚不清楚；即使发现病毒附着在细胞上也不能证明感染成功。来自不同海洋地点的高达 7% 的异养细菌和 5% 的蓝藻含有成熟噬菌体；通过培养数据的解释表明，高达 70% 的原核生物可能被感染。这些数据表明海洋食物网中存在重要的碳和氮循环新途径，并对海洋生物之间的基因转移具有进一步的影响。
DESPITE the importance of cyanobacteria in global primary productivity1and of heterotrophic bacteria in the consumption of organic matter in the sea2, the causes of their mortality, particularly the cyanobacteria, are poorly understood. It is usually assumed that mortality is due to protozoan grazing3,4rather than to viral infection, probably because abundances of phage and host in nature are presumed to be low5. Previously, either very few marine bacteriophages have been found by plaque assays6–9, or viruses have been simply observed10–12or counted13,14by transmission electron microscopy, with the assumption that 'phage-looking' forms are locally active bacteriophages. Here we report not only high viral abundance in the ocean but also counts of bacteria and cyanobacteria in the final irreversible stage of lytic infection. The latter counts are necessary to evaluate mortality, because the sources, hosts, viability and ages of observed free viruses are unknown; even finding viruses attached to cells does not prove successful infection. Up to 7% of the heterotrophic bacteria and 5% of the cyanobacteria from diverse marine locations contained mature phage; interpretation via culture data indicates that up to 70% of the prokaryotes could be infected. These data demonstrate the existence of a significant new pathway of carbon and nitrogen cycling in marine food webs and have further implications for gene transfer between marine organisms.