NUS Environmental Research Institute, National University of Singapore, Singapore, Singapore.
Department of Civil and Environmental Engineering, National University of Singapore, Singapore, Singapore.
Water Res. 2019 Feb 1;149:342-350. doi: 10.1016/j.watres.2018.11.022. Epub 2018 Nov 13.
This study aimed to examine the drivers in shaping the occurrence and distribution of total viruses and picoplankton in tropical freshwater ecosystems. Flow cytometry was used to quantify the concentrations of total viruses, picoheterotrophs, picophytoplankton, and picocyanobacteria. Three land use patterns (urban-, agriculture- and parkland-dominated) were evaluated using ArcGIS. Significant correlations were observed between water-borne microbial targets and water quality parameters (0.175 ≤ |r| ≤ 0.441), nutrients (0.250 ≤ r ≤ 0.570) and land use factors (0.200 ≤ |r| ≤ 0.460). In particular, the concentrations of total viruses and picoheterotrophic cells were higher in catchments whereas the abundances of picophytoplankton and picocyanobacteria were higher in reservoirs. Total viruses and picoplankton had higher concentrations in urban- and agriculture-dominated areas, probably due to anthropogenic inputs and agricultural inputs, respectively. Although surface water is a complex matrix influenced by niche-based (i.e., physicochemical properties, nutrients, land use impact etc.) and neutral-based factors (i.e., ecological drift, dispersal and species), land use patterns could help to elucidate the occurrence and distribution of the total microbial community at the macroscopic level. Meanwhile, inter-correlations among viruses, picoplankton and picoheterotrophs (0.715 ≤ r ≤ 0.990) also substantiates their mutual interactions in influencing the microbial community. Furthermore, the relationships between total microbial cells and bacterial and viral indicators were also investigated. Concentrations of total viruses, picoplankton and picoheterotrophs were positively correlated with bacterial indicators (0.427 ≤ r ≤ 0.590) and viral indicators (0.201 ≤ r ≤ 0.563). These results indicated that faecal and viral contamination could contribute to the numbers of total viruses and bacteria.
本研究旨在探讨驱动热带淡水生态系统中总病毒和微微型浮游生物发生和分布的因素。流式细胞术用于定量测定总病毒、微微型异养生物、微微型浮游植物和微微型蓝藻的浓度。使用 ArcGIS 评估了三种土地利用模式（城市、农业和公园主导）。观察到水传播微生物靶标与水质参数（0.175≤|r|≤0.441）、养分（0.250≤r≤0.570）和土地利用因素（0.200≤|r|≤0.460）之间存在显著相关性。特别是，总病毒和微微型异养细胞的浓度在集水区较高，而微微型浮游植物和微微型蓝藻的丰度在水库较高。总病毒和微微型浮游生物在城市和农业主导地区的浓度较高，可能分别是由于人为输入和农业输入。尽管地表水是一个复杂的基质，受到基于生态位的因素（即物理化学性质、养分、土地利用影响等）和基于中性的因素（即生态漂移、扩散和物种）的影响，但土地利用模式可以帮助阐明宏观水平上总微生物群落的发生和分布。同时，病毒、微微型浮游生物和微微型异养生物之间的相互关系（0.715≤r≤0.990）也证明了它们在影响微生物群落方面的相互作用。此外，还研究了总微生物细胞与细菌和病毒指标之间的关系。总病毒、微微型浮游生物和微微型异养生物的浓度与细菌指标（0.427≤r≤0.590）和病毒指标（0.201≤r≤0.563）呈正相关。这些结果表明，粪便和病毒污染可能导致总病毒和细菌数量增加。
