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Coliform Bacteria and Nitrogen Fixation in Pulp and Paper Mill Effluent Treatment Systems
- Source :
- Applied and Environmental Microbiology. 66:5155-5160
- Publication Year :
- 2000
- Publisher :
- American Society for Microbiology, 2000.
-
Abstract
- The majority of pulp and paper mills now biotreat their combined effluents using activated sludge. On the assumption that their wood-based effluents have negligible fixed N, and that activated-sludge microorganisms will not fix significant N, these mills routinely spend large amounts adding ammonia or urea to their aeration tanks (bioreactors) to permit normal biomass growth. N 2 fixation in seven Eastern Canadian pulp and paper mill effluent treatment systems was analyzed using acetylene reduction assays, quantitative nitrogenase ( nifH ) gene probing, and bacterial isolations. In situ N 2 fixation was undetectable in all seven bioreactors but was present in six associated primary clarifiers. One primary clarifier was studied in greater detail. Approximately 50% of all culturable cells in the clarifier contained nifH , of which >90% were Klebsiella strains. All primary-clarifier coliform bacteria growing on MacConkey agar were identified as klebsiellas, and all those probed contained nifH . In contrast, analysis of 48 random coliform isolates from other mill water system locations showed that only 24 (50%) possessed the nifH gene, and only 13 (27%) showed inducible N 2 -fixing activity. Thus, all the pulp and paper mill primary clarifiers tested appeared to be sites of active N 2 fixation (0.87 to 4.90 mg of N liter −1 day −1 ) and a microbial community strongly biased toward this activity. This may also explain why coliform bacteria, especially klebsiellas, are indigenous in pulp and paper mill water systems.
- Subjects :
- Paper
Microorganism
engineering.material
Biology
complex mixtures
Waste Disposal, Fluid
Applied Microbiology and Biotechnology
Microbial Ecology
Microbiology
Bioreactors
Enterobacteriaceae
Klebsiella
Nitrogen Fixation
Effluent
Ecosystem
DNA Primers
Base Sequence
Ecology
business.industry
Pulp (paper)
technology, industry, and agriculture
food and beverages
Paper mill
Pulp and paper industry
Coliform bacteria
Biodegradation, Environmental
Activated sludge
Genes, Bacterial
Nitrogen fixation
engineering
Water Microbiology
business
Food Science
Biotechnology
Waste disposal
Subjects
Details
- ISSN :
- 10985336 and 00992240
- Volume :
- 66
- Database :
- OpenAIRE
- Journal :
- Applied and Environmental Microbiology
- Accession number :
- edsair.doi.dedup.....1643c0316d8d32ef3d808a7efb12b75f
- Full Text :
- https://doi.org/10.1128/aem.66.12.5155-5160.2000