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Bacterial tracking of motile algae
Greg M Barbara1, James G Mitchell
1School of Biological Sciences, Flinders University of South Australia, G.P.O. Box 2100, Adelaide 5001, Australia.
FEMS Microbiology Ecology
|September 2, 2009
Summary
Marine bacteria can track moving nutrient sources like algae using a run and reverse chemotaxis strategy. This bacterial motility allows them to form temporary associations, enhancing nutrient uptake in ocean ecosystems.
Area of Science:
- Marine microbiology
- Planktonic ecology
- Bacterial chemotaxis
Background:
- Ocean turbulence and run-and-tumble chemotaxis were thought to prevent marine bacteria clustering around micro-scale nutrient sources.
- Recent findings indicate marine bacteria employ a run-and-reverse strategy.
Purpose of the Study:
- To investigate if marine bacteria using run-and-reverse chemotaxis can track moving micro-scale nutrient sources.
- To determine if marine bacteria can form transient associations with motile phytoplankton.
Main Methods:
- Observing interactions between marine bacteria (Pseudoalteromonas haloplanktis, Shewanella putrefaciens) and motile algae (Pavlova lutheri).
- Measuring bacterial swimming speeds during tracking and non-tracking behaviors.
- Analyzing bacterial turning responses and proximity to algae.
Main Results:
- Marine bacteria successfully tracked individual, motile algae, maintaining close proximity.
- Bacteria exhibited high speeds (up to 445 µm/s) while tracking and demonstrated directed turning behaviors.
- Tracking behavior was linked to increased nutrient uptake due to proximity and advection.
Conclusions:
- Marine bacteria can effectively track moving micro-scale nutrient sources using run-and-reverse chemotaxis.
- These bacteria form transient phyto-bacterial associations, enhancing nutrient acquisition.
- This highlights a significant link between primary and secondary producers in planktonic ecosystems.
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