Department of Plant and Soil Sciences, Delaware Biotechnology Institute, University of Delaware, Newark, DE 19711, USA.
FEMS Microbiol Ecol. 2012 Feb;79(2):474-86. doi: 10.1111/j.1574-6941.2011.01238.x. Epub 2011 Nov 21.
Despite significant implications of viral activity in sediment ecosystems, there are limited data describing how sediment viral assemblages respond to broader ecosystem changes. To document this, the spatial and temporal dynamics of viral and bacterial abundance (BA) and changes in the morphological distribution of viruses were examined within three salinity regions over 2 years. Viral abundances (VA) ranged from 0.2 to 17 × 10(10) viruses mL(-1) sediment while direct bacterial counts ranged from 3.8 to 37 × 10(8) cells mL(-1) sediment. Peaks and valleys in the abundance of extracted viruses and bacteria from surface sediments occurred simultaneously, with lows in February 2004 and highs in April 2003. Across all samples, viral and BA were positively correlated (P < 0.001). Vertical profiles showed a decrease in viral and BA with depth in sediments. Based on transmission electron microscopy results, viruses with diminutive capsids (20-50 nm) and from the Myoviridae and Podoviridae viral family types were dominant within surface sediments. The most morphologically diverse viral assemblages occurred in autumn samples from the sandy, polyhaline station and spring samples from the mesohaline station. Seasonal changes showed an average 72% decrease in VA from spring to winter. These observations support the view that viriobenthos assemblages are responsive to seasonal environmental changes and that viral processes have significant implications for the biogeochemical processes mediated by bacterial communities within Bay sediments.
尽管病毒活动对沉积生态系统有重要影响，但描述沉积病毒组合如何响应更广泛的生态系统变化的数据有限。为了记录这一点，在两年内，在三个盐度区域内检查了病毒和细菌丰度（BA）的时空动态以及病毒形态分布的变化。病毒丰度（VA）范围从 0.2 到 17×10(10) 个病毒 mL(-1) 沉积物，而直接细菌计数范围从 3.8 到 37×10(8) 个细胞 mL(-1) 沉积物。表层沉积物中提取的病毒和细菌丰度的峰值和低谷同时出现，2004 年 2 月和 2003 年 4 月出现低值。在所有样本中，病毒和 BA 呈正相关（P < 0.001）。垂直剖面显示病毒和 BA 随沉积物深度的增加而减少。根据透射电子显微镜结果，具有微小衣壳（20-50nm）的病毒和来自肌尾病毒科和短尾病毒科的病毒科类型在表层沉积物中占主导地位。形态最多样化的病毒组合出现在多盐性沙质站的秋季样本和中盐性站的春季样本中。季节性变化显示 VA 从春季到冬季平均减少 72%。这些观察结果支持这样一种观点，即病毒组合对季节性环境变化有反应，并且病毒过程对海湾沉积物中细菌群落介导的生物地球化学过程有重要影响。
