Virus decay and its causes in coastal waters
Virus decay and its causes in coastal waters
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DOI：
10.1128/aem.63.1.77-83.1997
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发表时间：
1997-01-01
影响因子：
4.4
通讯作者：
Fuhrman, JA
中科院分区：
文献类型：
--
作者：
Noble, RT;Fuhrman, JA
最近的证据表明，病毒在海洋微生物食物网中发挥着重要作用。为了了解这一作用，重要的是确定病毒去除和降解的速度和机制，我们使用空斑试验来检测播种到自然海水中的实验室培养病毒的传染性的衰变。测定了来自圣塔莫尼卡湾的本地病毒和来自北海的非本地病毒在圣莫尼卡湾沿岸海水中的传染性损失率。将病毒播种到经过各种处理的淡水中：用0.2亩微孔过滤器过滤以去除生物，加热至变性酶，并浓缩溶解的有机物以重建酶活性，然后将海水样品在全阳光下、黑暗中或玻璃下孵化，以分离病毒腐烂的病原体。太阳辐射总是会导致病毒感染性损失的速度增加，与从北海分离的非本地海洋噬菌体相比，来自圣莫尼卡湾的病毒分离株在未经处理的海水中在全日光下持续降解更慢(衰减率从4.1%到7.2%h(-1))。所有噬菌体都表现出对热不稳定物质降解的敏感性，因为在黑暗中热处理将衰减率降低到约0.5%~2.0%h(-1)，过滤使衰减率降低了不同程度，平均为20%。不耐热的高分子量溶解物质(>；30 kDa，可能是酶)约占最大衰减量的1/5，太阳辐射约占外来病毒最大衰减量的1/3~2/3，约占本地病毒最大衰减量的1/4~1/3，这表明进化上对局部光照水平的适应。我们的结果表明，阳光是病毒腐烂的一个重要因素，但也表明了海水中颗粒和溶解物质的重要性。
Recent evidence suggests that viruses play an influential role within the marine microbial food web. To understand this role, it is important to determine rates and mechanisms of virus removal and degradation, We used plaque assays to examine the decay of infectivity in lab-grown viruses seeded into natural seawater. The rates of loss of infectivity of native viruses from Santa Monica Bay and of nonnative viruses from the North Sea in the coastal seawater of Santa Monica Bay were determined. Viruses were seeded into fresh seawater that had been pretreated in various ways: filtration with a 0.2-mu m-pore-size filter to remove organisms, heat to denature enzymes, and dissolved organic matter enrichment to reconstitute enzyme activity, Seawater samples were then incubated in full sunlight, in the dark, or under glass to allow partitioning of causative agents of virus decay, Solar radiation always resulted in increased rates of loss of virus infectivity, Virus isolates which are native to Santa Monica Bay consistently degraded more slowly in full sunlight in untreated seawater (decay ranged from 4.1 to 7.2% h(-1)) than nonnative marine bacteriophages which were isolated from the North Sea (decay ranged from 6.6 to 11.1% h(-1)). All phages demonstrated susceptibility to degradation by heat-labile substances, as heat treatment reduced the decay rates to about 0.5 to 2.0% h(-1) in the dark, Filtration reduced decay rates by various amounts, averaging 20%. Heat-labile, high-molecular-weight dissolved material (>30 kDa, probably enzymes) appeared responsible for about 1/5 of the maximal decay, Solar radiation was responsible for about 1/3 to 2/3 of the maximal decay of nonnative viruses and about 1/4 to 1/3 of that of the native viruses, suggesting evolutionary adaptation to local light levels. Our results suggest that sunlight is an important contributing factor to virus decay but also point to the significance of particles and dissolved substances in seawater.