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A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities
Published on: December 25, 2015
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Understanding structure/function relationships in nitrifying microbial communities after cross-transfer between
Blanca M Gonzalez-Silva1,2, Kjell Rune Jonassen3,4, Ingrid Bakke3
1Department of Biotechnology and Food Science, Faculty of Natural Sciences and Technology, NTNU-Norwegian University of Science and Technology, Sem Saelands v. 6/8, N-7491, Trondheim, Norway. blanca.g.silva@ntnu.no.
Scientific Reports
|February 4, 2021
Summary
Nitrifying bacteria in moving bed biofilm reactors adapted to freshwater (FR) showed poor recovery in seawater, while seawater-adapted cultures (SR) demonstrated high resilience. Physiological plasticity and succession enable long-term adaptation to salinity changes.
Area of Science:
- Environmental microbiology
- Wastewater treatment
- Biofilm engineering
Background:
- Nitrification is crucial for removing ammonia from aquatic environments.
- Salinity fluctuations pose significant challenges to nitrifying microbial communities.
- Understanding microbial adaptation mechanisms is vital for optimizing wastewater treatment systems.
Purpose of the Study:
- To investigate the impact of abrupt salinity changes on nitrification in moving bed biofilm reactors (MBBRs).
- To compare the resilience and adaptation of freshwater- (FR) and seawater- (SR) adapted nitrifying communities.
- To elucidate the microbial community structure and functional responses to salinity stress.
Main Methods:
- Utilized two MBBRs inoculated with FR and SR nitrifying cultures.
- Exposed reactors to short- and long-term salinity cross-transfer.
- Quantified ammonia and nitrite oxidation rates.
- Analyzed microbial community structure using 16S rRNA gene deep sequencing.
Main Results:
- FR cultures showed limited recovery at seawater salinity.
- SR cultures exhibited high resistance to low-salt stress.
- Succession and physiological plasticity were key adaptation mechanisms.
- Some nitrifying bacteria demonstrated broad salinity tolerance.
Conclusions:
- Seawater-adapted (SR) nitrifying cultures are robust for ammonium removal in systems with variable salinity.
- Findings challenge the prevailing view on salinity's impact on nitrifying community structure.
- Physiological plasticity is a critical factor for microbial adaptation to environmental changes.
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