Viral infections as controlling factor of the deep biosphere

病毒可能是深层生物圈中的主要“捕食者”，并可能对土著微生物产生重大影响，为这一营养极度枯竭的栖息地提供不稳定的有机化合物。虽然病毒沿着不同ODP位点的深度分布的直接计数表明随着深度的增加病毒总体减少，但我们可以表明病毒与细胞的比率增加。从我们ODP Leg201培养物收集的13种代表性深生物圈细菌中的6种中诱导出丙酸杆菌，表现出不同的梅毒和肌病毒形态型。其中5个进行了全基因组测序。这些序列信息将用于设计特异性引物，用于对深层生物圈中的这些生物进行分子检测和定量。特别是数量和分布的根瘤菌感染辐射，这是非常丰富的地下沉积物，将被检查。我们将进一步关注以下问题：病毒分流在为深层生物圈种群提供必需营养方面有多重要？原生微生物的生理状态与病毒感染有何关系？

Viruses might be the main “predators” in the deep biosphere and possibly have a major impact on indigenous microorganisms in providing labile organic compounds for this extremly nutrient depleted habitat. While direct counting of viruses along depth profiles of various ODP sites indicated a general decrease with depth, we could show that the ratio of viruses vs. cells increased. Prophages were induced from six out of thirteen representative deep-biosphere bacteria of our ODP Leg 201 culture collection, exhibiting different morphotypes of sypho- and myoviruses. Five of them were subjected to whole genome sequencing. This sequence information will be used to design specific primers for a molecular detection and quantification of these phages in the deep biosphere. Especially the number and distribution of phages that infect Rhizobium radiobacter, which is highly abundant in subsurface sediments, will be examined. We will further focus on the following questions: How important is the viral shunt in providing essential nutrients for deep biosphere populations? How is the physiological state of indigenous microorganisms related to viral infections?