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Viruses as partners in spring bloom microbial trophodynamics
G Bratbak1, M Heldal, S Norland
1Department of Microbiology and Plant Physiology, University of Bergen, Jahnebakken. 5, 5007 Bergen, Norway.
Applied and Environmental Microbiology
|May 1, 1990
Summary
During a 1989 spring diatom bloom, researchers observed a microbial food web. Viruses were found to be active participants, influencing bacterial populations and diverting production from other food chains.
Area of Science:
- Marine microbiology
- Aquatic ecology
- Food web dynamics
Background:
- Spring diatom blooms are crucial events in marine ecosystems, fueling microbial food webs.
- Understanding the roles of different microbial groups, including viruses, is essential for ecosystem function.
Purpose of the Study:
- To investigate population dynamics of algae, bacteria, flagellates, and viruses during a spring diatom bloom.
- To elucidate the role of viruses within the microbial food web.
Main Methods:
- Monitoring population sizes of algae, bacteria, heterotrophic flagellates, and viruses.
- Observing microbial succession in the mucous layer of senescent diatoms.
Main Results:
- A food chain pattern was observed: diatom bloom supported bacteria, which in turn supported flagellates.
- Virus concentrations peaked after the diatom bloom, with a significant portion attaching to senescent diatoms.
- Bacterial and viral succession occurred in the diatom mucous layer.
Conclusions:
- Viruses are active components of the microbial food web, not merely inactive particles.
- Viruses contribute to bacterial lysis, redirecting bacterial production away from the grazing food chain.
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