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Shift from growth to nutrient-limited maintenance kinetics during biofilter acclimation
1Idaho National Engineering and Environmental Laboratory, Idaho Falls, Idaho 83415-2203, USA. chy@inel.gov
Biotechnology and Bioengineering
|July 19, 2008
Summary
Biofilter activity decreases post-acclimation due to cells entering maintenance metabolism. Nutrient addition can restore high activity by enabling renewed growth and increasing biomass in the biofilter bed.
Area of Science:
- Environmental Biotechnology
- Biochemical Engineering
Background:
- Biofilters shift to low-rate maintenance metabolism after the acclimation phase due to nutrient depletion.
- This metabolic shift explains the observed decrease in biofilter activity over time.
Purpose of the Study:
- To model the metabolic shift in biofilters from active growth to maintenance metabolism.
- To explain the post-acclimation decrease in biofilter activity.
- To investigate the effect of nutrient addition on biofilter performance.
Main Methods:
- Developed a metabolic model incorporating acclimation and maintenance phases.
- Simulated biofilter performance, including biomass changes during acclimation.
- Experimentally validated simulations using a hexane biofilter.
- Proposed two methods to estimate biomass changes from substrate conversion data.
Main Results:
- Model simulations predicted approximately 4 logarithms of biomass growth during acclimation.
- Experimental results confirmed the predicted biomass growth.
- Nutrient addition primarily restores high substrate consumption rates by enabling growth, secondarily increasing biomass.
Conclusions:
- The shift to maintenance metabolism is a key factor in post-acclimation biofilter activity decline.
- Nutrient addition can effectively enhance biofilter performance by reactivating growth.
- Biomass changes during acclimation can be estimated using substrate conversion data.
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