Trichloroethylene degradation by methane-oxidizing cultures grown with various nitrogen sources
Methane-oxidizing microorganisms exhibit great potential for vadose zone bioremediation since they grow on a gaseous substrate, are capable of cometabolically degrading a wide range of common subsurface contaminants, and fix molecular nitrogen as a nitrogen source. This paper reports the effects of supplying nitrogen as nitrate, ammonia, and molecular nitrogen on the growth, trichloroethylene (TCE) degradation capacity, and energy storage capacity of a mixed methane-oxidizing culture. Cells inoculated from a nitrate-supplied methane-oxidizing culture grew fastest while fixing atmospheric nitrogen when oxygen partial pressures were kept less than 8%. Cell growth and methane oxidation were more rapid for ammonia-supplied cells than for nitrate-supplied or nitrogen-fixing cells. However, nitrogen-fixing cells were capable of oxidizing TCE as efficiently as nitrate- or ammonia-supplied cells, and they exhibited the highest TCE transformation capacity of all three cultures both with and without formate as an exogenous reducing energy source. The TCE product toxicity was not as pronounced for the nitrogen-fixing cells as for the nitrate- or ammonia-supplied cells after exposure to high (20 mg/L) or low (2 mg/L) TCE concentrations. Energy storage in the form of poly-β-hydroxybutyrate was 20% to 30% higher for nitrogen-fixing cells; increased energy storage may be responsible for the higher transformation capacity of nitrogen-fixing cells when no external reducing energy was available. However, because nitrogen-fixing cells also exhibited the highest transformation capacity in the presence of formate, their cometabolic activity was enhanced beyond that which can be explained by increased energy storage alone.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
Document Type: Research Article
Publication date: 1996-01-01
More about this publication?
- Water Environment Research (WER) is published monthly, including an annual Literature Review. A subscription to WER includes access to the latest content back to 1992, as well as access to fast track articles. An individual subscription is valid for 12 months from month of purchase.
Water Environment Research (WER) publishes peer-reviewed research papers, research notes, state-of-the-art and critical reviews on original, fundamental and applied research in all scientific and technical areas related to water quality, pollution control, and management. An annual Literature Review provides a review of published books and articles on water quality topics from the previous year. Published as: Sewage Works Journal, 1928 - 1949; Sewage and Industrial Wastes, 1950 - 1959; Journal Water Pollution Control Federation, 1959 - Oct 1989; Research Journal Water Pollution Control Federation, Nov 1989 - 1991; Water Environment Research, 1992 - present.
- Editorial Board
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Membership Information
- Information for Advertisers
- WEF Bookstore
- Ingenta Connect is not responsible for the content or availability of external websites