Competition and protist predation are important regulators of riverine bacterial community composition and size distribution
| Autor: | Gabriela Martínez de la Escalera, Giampiero Batani, Claudia Piccini, Stefano Fazi, Germán Sánchez Pérez |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
river ecology media_common.quotation_subject Heterotroph nanoflagellates Aquatic Science medicine.disease_cause Competition (biology) Bacterial cell structure Predation 03 medical and health sciences Abundance (ecology) Grazing medicine filaments Ecology Evolution Behavior and Systematics media_common biology Bacteria Ecology Protist biology.organism_classification functional diversity 030104 developmental biology aggregates |
| Zdroj: | Journal of freshwater ecology 31 (2016): 609–623. doi:10.1080/02705060.2016.1209443 info:cnr-pdr/source/autori:Batani, Giampiero; Perez, German; Martinez de la Escalera, Gabriela; Piccini, Claudia; Fazi, Stefano/titolo:Competition and protist predation are important regulators of riverine bacterial community composition and size distribution/doi:10.1080%2F02705060.2016.1209443/rivista:Journal of freshwater ecology/anno:2016/pagina_da:609/pagina_a:623/intervallo_pagine:609–623/volume:31 |
| DOI: | 10.1080/02705060.2016.1209443 |
| Popis: | Among the bacterivorous protists, heterotrophic nanoflagellates (HNFs) are considered to be the main grazers of bacteria in freshwaters due to their size-selective grazing. In this work, we assessed the change of a riverine bacterial community in controlled incubations, where HNFs' predation pressure was initially released through filtration. Filtration did not prevent the passage of cysts, which grew in the enrichments afterwards. Data on the composition of the bacterial community were gathered by Catalyzed Reporter Deposition Fluorescent In situ Hybridization (CARD-FISH) using 16S probes targeting phylogenetic groups. Bacterial cell size was also examined using image analysis. Overall, the initial filtration directly (through release of predation pressure) or indirectly (through competition among bacterial groups) affected the bacterial community composition. When nanoflagellate abundance rose, a reduction of bacterial abundance and changes in cell size distribution were observed. Gamma-Proteobacteria and Actinobacteria were the groups showing the greatest reduction in abundance. Beta-Proteobacteria showed a reduction of cell size and were found in aggregates. Alpha-Proteobacteria and Actinobacteria developed two distinct filamentous morphotypes: short, segmented rods and long chains of rods. Our results showed that the release of the predation pressure and the successive rise of the nanoflagellates changed the bacterial community in terms of composition at large phylogenetic scale. HNF grazing is highly group-specific and seems to reconstruct the community based on cell size, and thus, not only drastically changing the bacterial community composition, but also increasing its functional diversity. |
| Databáze: | OpenAIRE |
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