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Published on: September 1, 2020
Nucleic acids: indicators for dynamic processes of clogging in soil filter systems
1Institute for Water and River Basin Management, Division of Aquatic Environmental Engineering, Universität Karlsruhe, Adenauerring 20b, D-76128 Karlsruhe, Germany. schwarz@iwg.uka.de
Summary
Microbial biomass, measured by DNA concentration, causes soil filter clogging. RNA/DNA ratios indicate similar microbial growth rates in clogged and unclogged filters, suggesting adaptation.
Area of Science:
- Environmental microbiology
- Biogeochemistry
Background:
- Soil filters are crucial for wastewater treatment.
- Understanding microbial dynamics is key to filter efficiency.
Purpose of the Study:
- To quantify DNA, rRNA, and tRNA in a soil filter using HPLC.
- To correlate nucleic acid concentrations with microbial biomass and growth rates.
- To investigate the role of microbial biomass in soil filter clogging.
Main Methods:
- High-performance liquid chromatography (HPLC) for nucleic acid quantification.
- Sampling at various depths and sections of clogged and unclogged soil filters.
- Analysis of DNA as a microbial biomass indicator and RNA/DNA ratio for growth rate.
Main Results:
- Highest DNA concentrations (microbial biomass) were observed in the top 0-2 cm of the clogged filter.
- A three-month starvation period led to a twofold decrease in DNA and RNA concentrations in the top 0-8 cm.
- Higher nucleic acid concentrations at 10-40 cm in the unclogged filter suggested microbial shifts.
- Similar RNA/DNA ratios in both filter types indicated comparable microbial growth rates and metabolic activity.
Conclusions:
- Microbial biomass, quantified by DNA concentration, is the primary cause of soil filter clogging.
- The RNA/DNA ratio serves as a reliable indicator of microbial growth rates and metabolic activity in soil filters.
- Soil filter performance is directly linked to microbial community dynamics and biomass accumulation.
