NADPH-dependent glutamate dehydrogenase in Penicillium chrysogenum is involved in regulation of β-lactam production

Abstract

The interactions between the ammonium assimilatory pathways and b-lactam production were investigated by disruption of the NADPH-dependent glutamate dehydrogenase gene (gdhA) in two industrial b-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 b-lactam production was detected in either of the DgdhA strains. Supplementation with glutamate restored growth but no b-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 b-lactam production for the reference strains whereas the DgdhA strains remained non-productive under all conditions. By overexpressing the NAD-dependent glutamate dehydrogenase, the specific growth rate could be restored, but still no b-lactam production was detected. The results indicate that the NADPH-dependent glutamate dehydrogenase may be directly or indirectly involved in the regulation of b-lactam production in industrial strains of P. chrysogenum.

The Penicillium Chrysogenum Extracellular Proteome. Conversion from a Food-rotting Strain to a Versatile Cell Factory for White Biotechnology

“…As it was observed during the comparison of the the wild-type strain versus the Wis 54 -1255 strain, some proteins overrepresented or only detected in the latter strain lack predicted secretion signal sequences. Examples are provided by an enolase (spots Wa13-Wa15), a probable mitochondrial (homo) aconitate hydratase Aco1 (spots Wa20-Wa22), a probable glucose-6-phosphate 1-dehydrogenase (spot Wa27), a probable ribose 5-phosphate isomerase RPI (spot Wa40), a probable transaldolase Tal1 (spots Wa48), and the glutamate dehydrogenase GDHA (spots Wa26, Wa30), the latter reported to be involved in regulation of ␤-lactam production (64). Several of these enzymes play roles related to the mitochondrial formation of the penicillin precursor ␣-aminoadipic acid and may be released by some type of vesicles.…”

Disruption of the NADPH-dependent glutamate dehydrogenase affects the morphology of two industrial strains of Penicillium chrysogenum

“…The two strains are isogenic except for the insertion of the Streptomyces clavuligerus expandase gene into the genome of PC-ceph. In these two strains, the NADPH-dependent glutamate dehydrogenase was deleted by replacing 0.8 kb of the cteminus of the gdhA gene with the Hygromyin B resistance marker, resulting in PC-pen-gdhA and PC-ceph-gdhA (Thykaer et al, 2008). Wild type Aspergillus nidulans strain (A187) and the corresponding gdhA strain (A699) obtained from FGSC were also applied.…”

“…During physiological characterisation of two industry related strains of P. chrysogenum, both carrying a disruption in the NADPH-dependent glutamate dehydrogenase (gdhA) gene (Thykaer et al, 2008), it was observed that this genetic modification had resulted in considerable changes in morphology. This apparent change was investigated in detail and the results are presented.…”

“…# Strains donated by DSM, anti-infectives, NL, * strains constructed in a previous study(Thykaer et al, 2008), ¤ strains obtained from Fungal Genetics Stock Center, University of Missouri, Kansas city, Missouri, USA.…”

Comprehensive Profiling of Proteome Changes Provide Insights of Industrial Penicillium chrysogenum During Pilot and Industrial Penicillin G Fermentation

“…Jami et al also demonstrated that the cysteine biosynthesis (a penicillin precursor) and enzymes of the PPP were increased dramatically in the high producer strains of P. chrysogenum [15]. The NADPH-dependent glutamate dehydrogenase might be directly or indirectly involved in the regulation of beta-lactam production in industrial strains of P. chrysogenum [16]. Several studies presented metabolic flux and metabolic network analysis in the glycolysis and PPPs of P. chrysogenum [17,18].…”