Induction and repression of alpha-amylase production in batch and continuous cultures of Aspergillus oryzae.
The intra- and extracellular concentrations of alpha-amylase in Aspergillus oryzae have been measured during batch culture of a wild-type strain and two recombinant strains. The mean intracellular level for the two recombinant strains was about four to five times the level of the wild-type strain. The recombinant strains also had a higher alpha-amylase productivity, whereas the residence time of the intracellular alpha-amylase pool was approximately the same for the three strains. At high glucose concentrations there was a low constitutive synthesis of alpha-amylase, whereas at low glucose concentrations derepression resulted in an increased production rate. Shifts from a glucose- to a maltose-limited chemostat showed that maltose induces both the production and secretion of alpha-amylase. Finally, from immunoblots, both a glycosylated and an unglycosylated alpha-amylase have been detected.
Mørkeberg
R
R
Department of Biotechnology, Technical University of Denmark, Lyngby, Denmark.
Carlsen
M
M
Nielsen
J
J
D000581:Amidohydrolases / Q000378:metabolism; D001236:Aspergillus oryzae / Q000201:enzymology* / Q000254:growth & development; D002455:Cell Division; D004790:Enzyme Induction; D004794:Enzyme Repression; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D005947:Glucose / Q000378:metabolism; D006031:Glycosylation; D008320:Maltose / Q000378:metabolism; D009172:Mycology / Q000379:methods; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase; D013213:Starch / Q000378:metabolism; D000516:alpha-Amylases / Q000096:biosynthesis*
D008320:Maltose; D013213:Starch; D000516:alpha-Amylases; D000581:Amidohydrolases; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase; D005947:Glucose