morphological and physiological evolution of Aspergillus terreus mycelium in the submerged culture and its relation to the formation of secondary metabolites

• Published in: World journal of microbiology & biotechnology 2010, Vol.26 (1), p.41-54
• Main Authors: Bizukojc, M, Ledakowicz, S
• Format: Article
• Language: English
• Subjects: Applied Microbiology; Aspergillus terreus; Bacteria; Batch processes; Biochemistry; Biological and medical sciences; Biomedical and Life Sciences; Biosynthesis; Biotechnology; Drugs; Environmental Engineering/Biotechnology; Evolution; Experiments; Fundamental and applied biological sciences. Psychology; Fungi; Investigations; Life Sciences; Metabolites; Microbiology; Morphology; Original Paper; Penicillin; Pharmaceutical industry; Physiology; Secondary metabolites; Studies
• ISSN: 0959-3993; 1573-0972
• DOI: 10.1007/s11274-009-0140-1

The influence of the morphology and differentiation of Aspergillus terreus hyphae on the formation of mevinolinic acid (lovastatin) and (+)-geodin was tested. Lovastatin titre was the highest (above 60 mg l⁻¹) in the system with smaller pellets (diameter below 1.5 mm) and high biomass concentration (above 10 g l⁻¹ in the idiophase). These biomass features were induced by the higher initial number of spores in the preculture (above 2 × 10¹⁰ l⁻¹). At the initial number of spores below 2 × 10⁹ l⁻¹ (+)-geodin biosynthesis was the most efficient but it was rather connected with the elevated C/N ratio than with the pellet size. In order to quantify the hyphal differentiation in fungal pellets a special approach was used. The sectioning of the stained pellets together with the image analysis and calculation procedures were applied. The analysis of hyphal differentiation indicated that lovastatin formation was correlated with the fraction of the active, growing hyphae.