IRD, UMR 5119 ECOLAG, Montpellier, France.
FEMS Microbiol Lett. 2010 Oct;311(2):113-8. doi: 10.1111/j.1574-6968.2010.02074.x. Epub 2010 Aug 23.
Little is known about the ability of phages to successfully colonize contrasting aquatic niches. We conducted experimental cross-infections between viruses and prokaryotes from three tropical sites of West Africa, with distinct salinities: a freshwater reservoir, a marine coastal station and a hypersaline lake. A cellular poison-based method (potassium cyanide) revealed that the addition of native viruses (regardless of the water type) consistently stimulated viral production. Conversely, in all incubations conducted with allochtonous (non-native) viruses, their overall production was not promoted, which suggests a lytic failure. Prokaryotic heterotrophic production increased in fresh and marine water supplemented with native viruses, but not in the hypersaline water. These results point to the role of the viral shunt in low-salinity environments, where the release of bioavailable lysis products might be of high nutritional value for the noninfected prokaryotes. In contrast, in hypersaline water where glycerol is a major carbon and energy source for the heterotrophic community, dissolved organic matter (DOM) of lytic origin may represent a less important DOM source for prokaryotes. Finally, our results suggest that cosmopolitan phages capable of moving between biomes are probably rare in aquatic habitats, supporting the common idea that most wild phages are relatively limited in their host range.
关于噬菌体成功定殖于不同水生小生境的能力，人们知之甚少。我们在西非三个具有不同盐度的热带地点（一个淡水水库、一个海洋沿海站和一个高盐湖泊）进行了病毒和原核生物的交叉感染实验。基于细胞毒素的方法（氰化钾）表明，添加本地病毒（无论水类型如何）都能持续刺激病毒的产生。相反，在所有用异源（非本地）病毒进行的孵育中，它们的总体产量都没有增加，这表明裂解失败。在添加了本地病毒的淡水和海水中，异养原核生物的产量增加，但在高盐水中则没有增加。这些结果表明了病毒短路在低盐环境中的作用，在这种环境中，释放出的生物可利用的裂解产物对未感染的原核生物可能具有很高的营养价值。相比之下，在高盐水中，甘油是异养群落的主要碳源和能源，而裂解来源的溶解有机物质（DOM）可能对原核生物来说是一个不太重要的 DOM 来源。最后，我们的结果表明，能够在生物群落之间移动的世界性噬菌体在水生栖息地中可能很少见，这支持了一个普遍的观点，即大多数野生噬菌体的宿主范围相对有限。
