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Published on: July 16, 2017
Effect of nutrient periodicity on microbial community dynamics
Militza Carrero-Colón1, Cindy H Nakatsu, Allan Konopka
1Department of Biological Sciences, Purdue University, West Lafayette, IN 47907-2054, USA.
Applied and Environmental Microbiology
|May 5, 2006
Summary
Microbial communities shift dynamically with nutrient availability. Irregular nutrient pulses alter bacterial growth rates and community structure, even with similar physiological traits within replicates.
Area of Science:
- Microbial Ecology
- Environmental Microbiology
- Bacterial Physiology
Background:
- Microbial communities are shaped by nutrient availability.
- Growth rate and substrate affinity influence competitive fitness in changing environments.
Purpose of the Study:
- To investigate how temporal nutrient changes affect bacterial community structure and function.
- To test the hypothesis that growth rate and substrate affinity drive competitive fitness under fluctuating nutrient conditions.
Main Methods:
- Planktonic bacterial communities were exposed to nutrient additions at varying intervals (1, 3, 7, 14 days).
- Community structure was monitored using 16S rRNA gene PCR-denaturing gradient gel electrophoresis.
- Bacterial isolates were cultivated to assess physiological characteristics like growth rate and enzyme activity.
Main Results:
- Bacterial growth rates decreased as nutrient pulse intervals increased.
- Community composition changed continuously over 130 days for pulse intervals longer than 1 day.
- Isolates from frequently pulsed systems exhibited higher growth rates and ectoaminopeptidase activity.
Conclusions:
- Regular environmental changes, even simple ones, create dynamic microbial communities.
- Bacterial physiological traits are consistent with observed community-level responses to nutrient fluctuations.
- The presence of diverse species capable of utilizing the limiting substrate contributes to community adaptability.
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