The Nitrogenase in a Methanogenic Archaebacterium and Its Regulation
Abstract
The objectives of this project are to gain an understanding of nitrogen fixation in the archaebacterium Methanosacina barkeri strain 227, and to compare the process with that in eubacteria. Nitrogen fixation is energetically costly to strain 227, as it is to eubacteria. Diazotrophic growth was stimulated by Molybdenum and inhibited by tungsten, suggesting that the nitrogenase is a molybdoenzyme. We have purified the nitrogenase 30-40-fold, and have found that it is a two-component enzyme, as in eubacteria. Crude extracts and purified enzyme preparations show very low acetylene reducing activity and nitrogen is used preferentially to acetylene, similar to certain alternative nitrogenases in eubacteria. The component 2 analogue in strain 227 is absent in Western blots from ammonia-grown cells, consistent with ammonia repression of nitrogenase. Archaebacteria, Nitrogen fixation, Nutrition, Enzymes, Bacteriology, Microbiology, Diazotrophic growth.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 02, 1990
- Accession Number
- ADA218346
Entities
People
- Stephan H. Zinder