An extracellular—Pepstatin insensitive acid protease produced by Thermoplasma volcanium

• Published in: Bioresource technology Vol. 98; no. 1; pp. 112 - 117
• Main Authors: KOCABIYIK, Semra, ÖZEL, Hatice
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 2007; Elsevier Science
• Subjects: Acid protease; Animals; Bacterial Proteins - metabolism; Biological and medical sciences; Biotechnology; Cattle; Enzyme engineering; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration; Metals; Methods. Procedures. Technologies; Milk - chemistry; Milk - metabolism; Pepstatin-insensitive acid protease; Production of selected enzymes; Serine Endopeptidases - metabolism; Temperature; Thermoplasma - enzymology; Thermoplasma volcanium; Thermostable; Acid protease; Thermostable; Thermoplasma volcanium; Pepstatin-insensitive acid protease; Archaeobacteria; Enzyme; Acid proteinase; Extracellular; Peptidases; Pepstatin; Enzyme production; Bacteria; Hydrolases; Thermoplasma
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2005.11.016

In this study, some parameters for the production and caseinolytic activity of an extracellular thermostable acid protease from a thermoacidophilic
archaeon Thermoplasma volcanium were determined. The highest level of growth and enzyme production were detected at pH 3.0 over an incubation period of 192
h at 60
°C. The pH optimum for the acid protease activity was 3.0 and the enzyme was fairly stable over a broad pH range (pH 3.0–8.0). The temperature for maximum activity of the enzyme was 55
°C and activity remained stable between 50
°C and 70
°C. These features could be of relevance for various biotechnological applications of this enzyme. Serine-(PMSF), cysteine-(DTT), metallo-(EDTA) and aspartate-(pepstatin) protease inhibitors did not inhibit the caseinolytic activity of the enzyme. Therefore,
Tp. volcanium acid protease could be a member of the pepstatin-insensitive carboxyl proteinases.