Scanning electron microscopy of immobilized Humicola lutea during semicontinuous production of acid proteinases

• Published in: World journal of microbiology & biotechnology Vol. 13; no. 1; pp. 57 - 61
• Main Authors: Michailova, L, Aleksieva, P
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 1997
• Subjects: Biological and medical sciences; Biological Sciences; Biotechnology; Fundamental and applied biological sciences. Psychology; Humicola lutea; Immobilization of organelles and whole cells; Immobilization techniques; Methods. Procedures. Technologies; plant anatomy; plant morphology; Scanning electron microscopy; Microorganism growth; Support; Enzyme; Immobilization; Acid proteinase; Fermentation; Fungi; Hydroxyethyl methacrylate polymer; Peptidases; Morphology; Hydrolases; Acrylamide polymer; Fungi Imperfecti; Entrapped microorganism; Mycelium; Semicontinuous; Thallophyta
• ISSN: 0959-3993; 1573-0972
• DOI: 10.1007/BF02770808

The morphology of the fungus Humicola lutea (strain 120-5), immobilized in polyacrylamide and polyhydroxyethylmethacrylate and used for the semicontinuous production of acid proteinases, was examined by scanning electron microscopy. The fungus developed a dense mycelium below the bead surface as well as in the bead interior after precultivation of entrapped spores. During maximal semicontinuous enzyme biosynthesis, formation of numerous large bulbous cells with a different shape was observed. Lysis of the cells was observed mainly in the centre of the gel beads after 13 successive fermentations with polyacrylamide-immobilized cells or after 21 re-uses of polyhydroxyethylmethacrylate-immobilized mycelia, respectively. Growth and changes in the cellular morphology of immobilized H. lutea, accompanying biosynthesis of acid proteinases, were comparable in both gel matrices but mycelia immobilized in polyhydroxyethylmethacrylate maintained their productivity twice as long.