Journal article
NADPH-dependent glutamate dehydrogenase in Penicillium chrysogenum is involved in regulation of beta-lactam production
The interactions between the ammonium assimilatory pathways and beta-lactam production were investigated by disruption of the NADPH-dependent glutamate dehydrogenase gene (gdhA) in two industrial beta-lactam-producing strains of Penicillium chrysogenum. The strains used were an adipoyl-7-ADCA- and a penicillin-producing strain.
The gdhA gene disruption caused a decrease in maximum specific growth rate of 26 % and 35 % for the adipoyl-7-ADCA-producing strain and the penicillin-producing strain, respectively, compared to the corresponding reference strains. Interestingly, no beta-lactam production was detected in either of the Delta gdhA strains.
Supplementation with glutamate restored growth but no beta-lactam production was detected for the constructed strains. Cultures with high ammonium concentrations (repressing conditions) and with proline as nitrogen source (de-repressed conditions) showed continued beta-lactam production for the reference strains whereas the Delta gdhA strains remained non-productive under all conditions.
By overexpressing the NAD-dependent glutamate dehydrogenase, the specific growth rate could be restored, but still no beta-lactam production was detected. The results indicate that the NADPH-dependent glutamate dehydrogenase may be directly or indirectly involved in the regulation of beta-lactann production in industrial strains of P. chrysogenum.
Language: | English |
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Year: | 2008 |
Pages: | 1242-1250 |
ISSN: | 14652080 and 13500872 |
Types: | Journal article |
DOI: | 10.1099/mic.0.2007/010017-0 |
ORCIDs: | Kildegaard, Kanchana Rueksomtawin |