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A Lipid Extraction and Analysis Method for Characterizing Soil Microbes in Experiments with Many Samples
Published on: July 16, 2017
Link between microbial composition and carbon substrate-uptake preferences in a PHA-storing community.
Maria G E Albuquerque1, Gilda Carvalho, Caroline Kragelund
1REQUIMTE/CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Lisboa, Portugal.
The ISME Journal
|July 20, 2012
Summary
Microbial communities in a sequencing batch reactor (SBR) efficiently produced polyhydroxyalkanoates (PHAs) from fermented molasses. Different bacterial populations specialized in consuming specific volatile fatty acids, ensuring stable PHA production.
Area of Science:
- Microbiology
- Environmental Biotechnology
- Biochemical Engineering
Background:
- Polyhydroxyalkanoates (PHAs) are biodegradable polymers with diverse applications.
- Optimizing microbial communities in sequencing batch reactors (SBRs) is crucial for efficient PHA production.
- Understanding substrate utilization by microbial consortia is key to enhancing bioprocess performance.
Purpose of the Study:
- To identify and quantify the microbial community structure in a molasses-fed SBR for PHA production.
- To investigate the substrate preferences and utilization capabilities of dominant microbial populations.
- To correlate microbial community composition and function with reactor performance.
Main Methods:
- 16S rRNA gene clone library analysis for microbial identification and quantification.
- Fluorescence in situ hybridization (FISH) for in situ visualization and enumeration of microbial populations.
- Microautoradiography-FISH (MAR-FISH) to determine substrate uptake specificities.
- Analysis of volatile fatty acid (VFA) composition in fermented molasses.
Main Results:
- The microbial enrichment was dominated (84%) by PHA-storing bacteria, including genera Azoarcus, Thauera, and Paracoccus.
- High PHA-storage efficiency (up to 60% PHA content) was achieved, indicating functional stability.
- Microbial populations exhibited substrate specialization: Azoarcus consumed acetate, Thauera consumed butyrate, and Paracoccus utilized a broader range of substrates.
- Differences in substrate uptake capabilities correlated with species composition and influenced VFA removal rates.
Conclusions:
- The SBR microbial community structure, dominated by specialized PHA-accumulating bacteria, ensures high and stable PHA production.
- Microbial niche differentiation based on substrate specialization allows for the co-existence of different populations in the SBR.
- Targeted manipulation of microbial communities and substrate availability can further optimize PHA bioproduction processes.
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