Viral lysis and bacterivory as prokaryotic loss factors along a salinity gradient
Viral lysis and bacterivory as prokaryotic loss factors along a salinity gradient
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DOI：
10.3354/ame011215
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发表时间：
1996-12-31
影响因子：
1.4
通讯作者：
PedrosAlio, C
中科院分区：
文献类型：
--
作者：
GuixaBoixareu, N;CalderonPaz, JI;PedrosAlio, C
我们估计原核死亡率，由于病毒和噬菌动物通过盐度梯度在2个太阳盐。在每个盐场系统中，连续的池塘提供了稳定状态的环境，盐度范围从千分之37到372。蛋白质和病毒丰度随盐度增加而增加，在盐度高于250 ppm时达到约10（8）个原核细胞ml（-1）和10（9）个病毒样颗粒（VLP）ml（-1）。在盐度为250 ‰以上时，直到梯度结束，蛋白质的倍增时间都超过2天。在较低盐度下，噬菌性占所有产量，但在最高盐度下为零。可见感染细胞的百分比在可以检测到感染细胞的池塘之间没有差异，并且总是低于4%。根据感染细胞的百分比并使用文献中的转换因子，我们估计了由于病毒裂解导致的原核死亡率：每天约有0.6至2 × 10（6）个原核生物ml（-1）被盐藻中的Te病毒裂解。与食细菌动物造成的原核生物损失（0.2至4 x 10（7）个细菌ml（-1）d（-1））相比，该数字代表了低百分比的原核丰度和产量。然而，由于在原核生物的特定形态型中发现的大爆发大小（200个病毒细胞（-1）），方形古细菌，病毒产量在250份/千盐度以上达到高于10（8）VLP ml（-1）d（-1）的值。这些古生菌代表了25%以上的原核生物组合高于250份每千盐度。在这一点上，它们成为原核形态型，感染细胞的百分比最大（1至10%的方形古细菌内部有可见的细菌）。发现一种柠檬形病毒（类似于其他一些古细菌的描述）感染方形古细菌，其丰度在最咸的池塘中与方形古细菌一起增加。在该系统中，病毒对原核丰度和生长速率没有强有力的控制。
We estimated prokaryotic mortality due to viruses and bacterivores through salinity gradients in 2 solar salterns. In each saltern system, successive ponds provided steady state environments with a range of salinities from 37 to 372 parts per thousand. Prokaryotic and viral abundance increased with salinity, reaching about 10(8) prokaryotic cells ml(-1)and 10(9) virus-like particles (VLP) ml(-1) at salinities higher than 250 parts per thousand. Prokaryotic doubling times became longer than 2 d above 250 parts per thousand salinity until the end of the gradient. Bacterivory accounted for all the production at lower salinities but it was found to be zero at the highest salinities. The percentage of visibly infected cells was not different among the ponds where infected cells could be detected and it was always lower than 4%. From the percentage of infected cells and using conversion factors from the literature we estimated rates of prokaryotic mortality due to viral lysis: about 0.6 to 2 x 10(6) prokaryotes ml(-1) were lysed daily by Te viruses in the salterns. This number represented a low percentage of prokaryotic abundance and production compared to the prokaryotic losses due to bacterivores (0.2 to 4 x 10(7) bacteria ml(-1) d(-1)). However, viral production reached values higher than 10(8) VLP ml(-1) d(-1) above 250 parts per thousand salinity, due to the large burst size (200 viruses cell(-1)) found in a particular morphotype of prokaryotes, the square archaea. These archaea represented more than 25% of the prokaryotic assemblage above 250 parts per thousand salinity. At this point they became the prokaryotic morphotype with the largest percentage of infected cells (1 to 10% of square archaea with visible phages inside) A lemon-shaped virus (similar to one described for some other groups of archaea) was found infecting square archaea, its abundance increased in the saltiest ponds together with that of the square archaea. In this system viruses did not exert a strong control over the prokaryotic abundance and growth rate.