Metabolic heterogeneity (MH) occurs when isogenic microbial populations display cell-to-cell differences in metabolic traits, albeit exposed to homogeneous conditions. Despite the increasing focus on MH, its triggering factors remain largely unknown. In the present thesis, I used stable isotope probing and chemical imaging with nanoscale Secondary Ion Mass Spectrometry (nanoSIMS) to study MH at single-cell level, in model organisms, synthetic and natural communities, to understand i) how abiotic factors, biotic interactions and antibiotics exposure influence MH and ii) its potential ecological role. Moreover, I optimized sample preparation for chemical and high-resolution imaging and suggested two different indices as ‘unit measure’ of MH. As results, I have shown for the first time that MH is displayed by microorganisms under favorable growth conditions, although none of the tested abiotic factors prevailed as the main trigger of MH. I brought insights on how biotic interactions play a role in the functional heterogeneity using bacteria pseudo-fungi co-cultures. I found that antibiotics reduce Carbon and Nitrogen assimilation rates of targeted phylogenetic groups in river-water communities, while increasing their MH, pointing to its ecological importance in natural environments. To conclude, I provided novel insights on the phenomenon of MH and its dynamics at different ecological scales.:Abbreviation list
Summary
Introduction
Knowledge gaps
Results and discussion
- Optimization of sample preparation
- Validation of quantitation methods
- Abiotic factors shaping metabolic heterogeneity in bacterial populations
- Influence of biotic factors in shaping heterogeneity
- Metabolic Heterogeneity and ecophysiology of natural microbial populations
influenced by emerging contaminants
Conclusions
Outlook
Bibliography
Appendix
Acknowledgments
Curriculum Vitae
List of publications
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:76344 |
| Date | 04 November 2021 |
| Creators | Calabrese, Federica |
| Contributors | Schlömann, Michael, Harms, Hauke, Musat, Niculina, Technische Universität Bergakademie Freiberg, Helmholtz Centre for Environmental Research - UFZ |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | doc-type:doctoralThesis, info:eu-repo/semantics/doctoralThesis, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | 10.1111/1462-2920.15756, 10.1116/1.5143203, 10.3389/fmicb.2019.02814, 10.3389/fmicb.2018.02342 |
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