Ammonia assimilation and glutamate incorporation in coenzyme F420 derivatives of Methanosarcina barkeri.
Methanosarcina barkeri was able to grow on L-alanine and L-glutamate as sole nitrogen sources. Cell yields were 0.5 g/l and 0.7 g/l (wet wt), respectively. The mechanism of ammonia assimilation in Methanosarcina barkeri strain MS was studied by analysis of enzyme activities. Activity levels of nitrogen-assimilating enzymes in extracts of cells grown on different nitrogen sources (ammonia, 0.05-100 mM; L-alanine, 10 mM; L-glutamate, 10 mM) were compared. Activities of glutamate dehydrogenase, glutamate synthase, glutamine synthetase, glutamate oxaloacetate transaminase and glutamate pyruvate transaminase could be measured in cells grown on these three nitrogen sources. Alanine dehydrogenase was not detected under the growth conditions used. None of the measured enzyme activities varied significantly in response to the NH4+ concentration. The length of the poly-gamma-glutamyl side chain of F420 derivatives turned out to be independent of the concentration of ammonia in the culture medium.
Department of Microbiology, Faculty of Science, University of Nijmegen, Toernooiveld, The Netherlands.
P C
PC
Raemakers-Franken
R J
RJ
Brand
A J
AJ
Kortstee
C
C
Van der Drift
G D
GD
Vogels
D000409:Alanine / Q000378:metabolism*; D000410:Alanine Transaminase / Q000378:metabolism; D000641:Ammonia / Q000378:metabolism*; D001219:Aspartate Aminotransferases / Q000378:metabolism; D002455:Cell Division; D002851:Chromatography, High Pressure Liquid; D003470:Culture Media; D019605:Euryarchaeota / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D005969:Glutamate Dehydrogenase / Q000378:metabolism; D005970:Glutamate Synthase / Q000378:metabolism; D005974:Glutamate-Ammonia Ligase / Q000378:metabolism; D005971:Glutamates / Q000378:metabolism*; D018698:Glutamic Acid; D009584:Nitrogen; D012256:Riboflavin / Q000031:analogs & derivatives* / Q000378:metabolism
D003470:Culture Media; D005971:Glutamates; D018698:Glutamic Acid; C015084:coenzyme F420; D000641:Ammonia; D005970:Glutamate Synthase; D005969:Glutamate Dehydrogenase; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D005974:Glutamate-Ammonia Ligase; D009584:Nitrogen; D000409:Alanine; D012256:Riboflavin