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Initial nitrogen enrichment conditions determines variations in nitrogen substrate utilization by heterotrophic
Suchismita Ghosh1, Paul A Ayayee2, Oscar J Valverde-Barrantes3
1Department of Biological Sciences, Kent State University, Kent, OH, 44242, USA.
BMC Microbiology
|April 6, 2017
Summary
Bacterial communities in nitrogen-rich streams show diverse nitrogen (N) substrate use, but taxonomic composition remains similar, indicating functional redundancy in the N cycle.
Area of Science:
- Microbiology
- Environmental Science
- Biogeochemistry
Background:
- The nitrogen (N) cycle involves complex microbe-mediated transformations influenced by N compound diversity and concentration.
- Heterotrophic bacteria play a crucial role in these N transformations within aquatic ecosystems.
Purpose of the Study:
- To investigate the taxonomic diversity of heterotrophic bacteria.
- To assess nitrogen (N) substrate utilization patterns in bacteria from streams with varying N enrichment.
Main Methods:
- Isolation of heterotrophic bacteria from streams subjected to simple and complex N-enrichment.
- Analysis of taxonomic diversity among bacterial isolates.
- Evaluation of N substrate utilization capabilities of the bacterial assemblages.
Main Results:
- Bacterial taxonomic composition did not significantly differ across enrichment types, suggesting functional redundancy.
- Nitrogen (N) substrate utilization patterns varied within and among enrichment types, not strictly between simple and complex conditions.
- Some N substrate use patterns differed between complex and simple N-enrichments, while others showed unexpected similarities.
Conclusions:
- Available nitrogen (N) pools influence bacterial physiology and select for diverse metabolic abilities.
- Taxonomic affiliation is not a reliable predictor of N utilization capabilities in these bacterial communities.
- Functional redundancy is a key characteristic of microbial communities in nitrogen-rich environments.
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