Untersuchungen zur Regulation der Ammoniumassimilation von Candida maltosa

✍ Scribed by P. Casper; Doz. Dr. R. Bode; D. Birnbaum

• Publisher: John Wiley and Sons
• Year: 1985
• Tongue: English
• Weight: 453 KB
• Volume: 25
• Category: Article
• ISSN: 0233-111X
• DOI: 10.1002/jobm.3620250203

✦ Synopsis

Activities of umrnonia-metabolizing enzymes from Candida maltosa werc measured. The synthesis of glutamate and glutamine involves three primary enzymes: glutamate dehydrogenase (GDH), glutaminc synthetase (GS), and glutamate synthase (GOGAT). This yeast has two distinct GDH, the first responsible for glutamate catabolism, and the second solely biosynthetic. The GS is derepressed during growth on low ammonia or on a variety of alternative nitrogen murces, whereas the catabolic GDH (NAD) is repressed under this conditions. Ammonia limitation did not significantly affect GOGAT as well as biosynthetic GDH (NADP) levels. The relatively low &,-value for ammonia suggest that the GS is catalytically active during cell growth on low concentrations of ammonia. It seems that under N-limitation ammonia assimilation is uchieved viu GS/GOGAT and under N-excess via GDH/GS.

2-Oxoglutarat (2-OG) und Glutaminsaure sind fur viele Mikroorganisnien die Pri-