Spatio-Temporal Variations of High and Low Nucleic Acid Content Bacteria in an Exorheic River

PLoS One. 2016 Apr 15;11(4):e0153678. doi: 10.1371/journal.pone.0153678. eCollection 2016.

Abstract

Bacteria with high nucleic acid (HNA) and low nucleic acid (LNA) content are commonly observed in aquatic environments. To date, limited knowledge is available on their temporal and spatial variations in freshwater environments. Here an investigation of HNA and LNA bacterial abundance and their flow cytometric characteristics was conducted in an exorheic river (Haihe River, Northern China) over a one year period covering September (autumn) 2011, December (winter) 2011, April (spring) 2012, and July (summer) 2012. The results showed that LNA and HNA bacteria contributed similarly to the total bacterial abundance on both the spatial and temporal scale. The variability of HNA on abundance, fluorescence intensity (FL1) and side scatter (SSC) were more sensitive to environmental factors than that of LNA bacteria. Meanwhile, the relative distance of SSC between HNA and LNA was more variable than that of FL1. Multivariate analysis further demonstrated that the influence of geographical distance (reflected by the salinity gradient along river to ocean) and temporal changes (as temperature variation due to seasonal succession) on the patterns of LNA and HNA were stronger than the effects of nutrient conditions. Furthermore, the results demonstrated that the distribution of LNA and HNA bacteria, including the abundance, FL1 and SSC, was controlled by different variables. The results suggested that LNA and HNA bacteria might play different ecological roles in the exorheic river.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteria / isolation & purification*
  • China
  • DNA, Bacterial / analysis*
  • Environmental Monitoring / methods
  • Flow Cytometry
  • Fresh Water
  • Geography
  • Hydrogen-Ion Concentration
  • Multivariate Analysis
  • Nucleic Acids / analysis*
  • Rivers / microbiology*
  • Seasons
  • Spatio-Temporal Analysis
  • Temperature
  • Water Microbiology*

Substances

  • DNA, Bacterial
  • Nucleic Acids

Grants and funding

The authors are grateful to the financial support from National Key Basic Research Program of China (2015CB459000) and National Natural Science Foundation, China (31322012). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.