ISSN:
1432-072X
Keywords:
Lignin biodegradation
;
Sporotrichum pulverulentum
;
White-rot fungus
;
Ammonia assimilation
;
Glutamate dehydrogenase
;
Glutamine synthetase
;
Glutamate synthase
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Levels of ammonia-assimilating enzymes (glutamate dehydrogenase, glutamine synthetase, glutamate synthase) were determined in extracts of Sporotrichum pulverulentum grown under different conditions with respect to both nitrogen source and concentration. Evolution of 14CO2 from 14C-synthetic lignin by fungal cultures grown under parallel conditions was also determined as a measure of lignin decomposition and the suppressive effect of nitrogen on ligninolysis confirmed. Under low nitrogen conditions, fungal extracts exhibited relatively high levels of NADP-dependent glutamate dehydrogenase and glutamine synthetase dehydrogenase. Conversely, in high nitrogen extracts, lower levels of NADP-dependent glutamate dehydrogenase and glutamine synthetase activity, and higher levels of NAD-dependent glutamate dehydrogenase, were recorded. Possible effects of enzyme activities on intracellular pool concentrations of glutamate/glutamine, and the implications for the regulation of lignin metabolism, are discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00414996
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