English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The faecal indicator  Escherichia coli  plays a central role in water quality assessment and monitoring. It is therefore essential to understand its fate under various environmental constraints such as predation by bacterivorous zooplankton. Whereas most studies have examined how protozooplankton communities (heterotrophic nanoflagellates and ciliates) affect the fate of  E .  coli  in water, the capacity of metazooplankton to control the faecal indicator remains poorly understood. In this study, we investigated how the common filter-feeding cladoceran,  Daphnia pulex , affects the fate of  E .  coli  under different experimental conditions.  Daphnia  ingested  E .  coli  and increased its loss rates in water, but the latter rates decreased from 1.65 d -1  to 0.62 d -1  after a 1,000-fold reduction in  E .  coli  initial concentrations, due to lower probability of encounter between  Daphnia  and  E .  coli . The combined use of culture and PMA qPCR (viability-qPCR) demonstrated that exposure to  Daphnia  did not result into the formation of viable but non-culturable  E .  coli  cells. In lake water, a significant part of  E .  coli  population loss was associated with matrix-related factors, most likely due to predation by other bacterivorous biota and/or bacterial competition. However, when exposing  E .  coli  to a  D .  pulex  gradient (from 0 to 65 ind.L -1 ), we observed an increasing impact of  Daphnia  on  E .  coli  loss rates, which reached 0.47 d -1  in presence of 65 ind.L -1 . Our results suggest that the filter-feeder can exert a non-negligible predation pressure on  E .  coli , especially during seasonal  Daphnia  population peaks. Similar trials using other  Daphnia  species as well as stressed  E .  coli  cells will increase our knowledge on the capacity of this widespread zooplankter to control  E .  coli  in freshwater resources. Based on our results, we strongly advocate the use of natural matrices to study these biotic interactions in order to avoid overestimation of  Daphnia  impact.

How does the cladoceran Daphnia pulex affect the fate of Escherichia coli in water?