Dynamics of Bacterial and Fungal Communities during the Outbreak and Decline of an Algal Bloom in a Drinking Water Reservoir

Abstract

The microbial communities associated with algal blooms play a pivotal role in organic carbon, nitrogen and phosphorus cycling in freshwater ecosystems. However, there have been few studies focused on unveiling the dynamics of bacterial and fungal communities during the outbreak and decline of algal blooms in drinking water reservoirs. To address this issue, the compositions of bacterial and fungal communities were assessed in the Zhoucun drinking water reservoir using 16S rRNA and internal transcribed spacer (ITS) gene Illumina MiSeq sequencing techniques. The results showed the algal bloom was dominated by Synechococcus, Microcystis, and Prochlorothrix. The bloom was characterized by a steady decrease of total phosphorus (TP) from the outbreak to the decline period (p < 0.05) while Fe concentration increased sharply during the decline period (p < 0.05). The highest algal biomass and cell concentrations observed during the bloom were 51.7 mg/L and 1.9×108 cell/L, respectively. The cell concentration was positively correlated with CODMn (r = 0.89, p = 0.02). Illumina Miseq sequencing showed that algal bloom altered the water bacterial and fungal community structure. During the bloom, the dominant bacterial genus were Acinetobacter sp., Limnobacter sp., Synechococcus sp., and Roseomonas sp. The relative size of the fungal community also changed with algal bloom and its composition mainly contained Ascomycota, Basidiomycota and Chytridiomycota. Heat map profiling indicated that algal bloom had a more consistent effect upon fungal communities at genus level. Redundancy analysis (RDA) also demonstrated that the structure of water bacterial communities was significantly correlated to conductivity and ammonia nitrogen. Meanwhile, water temperature, Fe and ammonia nitrogen drive the dynamics of water fungal communities. The results from this work suggested that water bacterial and fungal communities changed significantly during the outbreak and decline of algal bloom in Zhoucun drinking water reservoir. Our study highlights the potential role of microbial diversity as a driving force for the algal bloom and biogeochemical cycling of reservoir ecology.

Temperature-controlled thermophilic bacterial communities in hot springs of western Sichuan, China

“…These approaches include direct 16S rRNA gene amplification and cloning, differentiation using amplified fragment length polymorphism (AFLP) [ 19 ], amplified ribosomal DNA restriction analysis (ARDRA) [ 20 ], denaturing gradient gel electrophoresis (DGGE) [ 21 ], and random amplified polymorphic DNA (RAPD) [ 22 ]. Numerous combined approaches have been also developed for the study of microbial communities, including scanning electron microscopy (SEM) combined with community level physiological profiles (CLPPs) [ 23 ] and other PCR/sequencing-based techniques [ 24 , 25 ].…”

Hidden diversity of micro-eukaryotes in Lake Baikal: a metagenomic approach

“…2A). Fungi contribute significantly to the organic matter decomposition and food web; they affect water quality and taxonomic composition of communities (Zhang et al, 2015;2018). Fungi from Irinda Bay were more abundant.…”

Community Compositions of Phytoplankton and Eukaryotes during the Mixing Periods of a Drinking Water Reservoir: Dynamics and Interactions

“…Water eukaryotic microorganism community sequence reads were filtered by the QIIME pipeline, and trimmed when they were shorter than 50 bp [15]. After assembling and quality filtering, sequences with ≥97% similarity were assigned to the same operational taxonomic units (OTUs) that were used to compute the Chao richness estimator (Chao1), Shannon diversity (H'), and Simpson diversity (D) index using the MOTHUR package (version 1.22.2, http://www.mothur.org) [1,15]. The most representative sequences for each OTU were selected, and we then used the Ribosomal Database Project (RDP) classifier (RDP Release 11.5, https://rdp.cme.msu.edu/) to annotate taxonomic information for each representative sequence [1].…”

“…A previous study conducted by Landa et al [48] indicated that a higher water iron concentration could contribute to the proliferation of algal blooms in oceans. However, recently, Zhang et al [1] have found that the concentration of Fe was at its lowest before the algal blooms, and that it increased markedly during the decline periods (p < 0.001). Compared with DOC and conductivity, concentrations of TN, NH 4 + -N and TP exhibited inverse trends, with the highest concentrations (as well as the highest concentrations of algal density) mainly observed in October.…”

“…The concentrations of dissolved organic carbon (DOC) were measured with a TOC analyzer (TOC-L CPN, Japan). Concentrations of iron (Fe) and manganese (Mn) were examined using flame atomic absorption spectrometry (FAAS, AA 6800, and Shimadzu, Japan) [1,2,42]. All the physicochemical analyses were performed within 48 h, and all parameters of this study were the averages of duplicate sample measurements.…”