A1 Journal article (refereed)
Top-down effects of a lytic bacteriophage and protozoa on bacteria in aqueous and biofilm phases (2014)

Zhang, J., Örmälä, A.-M., Mappes, J., & Laakso, J. (2014). Top-down effects of a lytic bacteriophage and protozoa on bacteria in aqueous and biofilm phases. Ecology and Evolution, 4(23), 4444–4453. https://doi.org/10.1002/ece3.1302

JYU authors or editors

Publication details

All authors or editors: Zhang, Ji; Örmälä, Anni-Maria; Mappes, Johanna; Laakso, Jouni

Journal or series: Ecology and Evolution

ISSN: 2045-7758

eISSN: 2045-7758

Publication year: 2014

Volume: 4

Issue number: 23

Pages range: 4444–4453

Publisher: John Wiley & Sons Ltd.

Publication country: United Kingdom

Publication language: English

DOI: https://doi.org/10.1002/ece3.1302

Research data link: https://doi.org/10.5061/dryad.mr0n8

Publication open access: Openly available

Publication channel open access: Open Access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/47974


Lytic bacteriophages and protozoan predators are the major causes of bacterial mortality in natural microbial communities, which also makes them potential candidates for biological control of bacterial pathogens. However, little is known about the relative impact of bacteriophages and protozoa on the dynamics of bacterial biomass in aqueous and biofilm phases. Here, we studied the temporal and spatial dynamics of bacterial biomass in a microcosm experiment where opportunistic pathogenic bacteria Serratia marcescens was exposed to particle‐feeding ciliates, surface‐feeding amoebas, and lytic bacteriophages for 8 weeks, ca. 1300 generations. We found that ciliates were the most efficient enemy type in reducing bacterial biomass in the open water, but least efficient in reducing the biofilm biomass. Biofilm was rather resistant against bacterivores, but amoebae had a significant long‐term negative effect on bacterial biomass both in the open‐water phase and biofilm. Bacteriophages had only a minor long‐term effect on bacterial biomass in open‐water and biofilm phases. However, separate short‐term experiments with the ancestral bacteriophages and bacteria revealed that bacteriophages crash the bacterial biomass dramatically in the open‐water phase within the first 24 h. Thereafter, the bacteria evolve phage‐resistance that largely prevents top‐down effects. The combination of all three enemy types was most effective in reducing biofilm biomass, whereas in the open‐water phase the ciliates dominated the trophic effects. Our results highlight the importance of enemy feeding mode on determining the spatial distribution and abundance of bacterial biomass. Moreover, the enemy type can be crucially important predictor of whether the rapid defense evolution can significantly affect top‐down regulation of bacteria.

Free keywords: Tetrahymena thermophila; Acanthamoeba castellanii; Aquatic bacteria; Defense evolution; Lytic bacteriophage; Microcosm; Semad11; Serratia marcescens db11; Top-down regulation

Contributing organizations

Other organizations:

Ministry reporting: Yes

Reporting Year: 2014

JUFO rating: 1

Last updated on 2021-09-08 at 13:50