Purification and Properties of Mucor pusillus Acid Protease

Abstract

The protease produced by Mucor pusillus was recovered from a wheat bran medium by treatment with ammonium sulfate, ethyl alcohol, gel filtration and ionexchange chromatography. The yield of the enzyme was 55 %. The overall increase in the specific activity of the protease was 34-fold. The purified protease was most active at pH 3.8 and 5.6 against hemoglobin and casein, respectively. Optimal hydrolysis of casein was observed at 55 C. The enzyme was stable from pH 3.0 to 6.0. Enzyme inactivated by metal ions was reactivated by ethylenediaminetetraacetate and o-phenanthroline. Reducing agents and thiol poisons had no effect on the protease, suggesting that free sulfhydryl groups were not required for enzyme activity. Diisopropyl fluorophosphate did not inhibit the protease, indicating the probable absence of serine in the active center. The Michaelis-Menten constant for casein was 0.357%. Electrophoretic analysis of active protein recovered by ion-exchange chromatography showed that the protease preparation was homogeneous.

Extracellular protease from Mucor pusillus: purification and characterization

“…Our result is in concordance with those observed by Somkuti and Babel (1968). Purification of crude enzyme yielded a preparation that, upon gel filtration, ion‐exchange chromatography and electrophoresis analysis, appeared to be homogeneous.…”

Hydrolysis of proteinaceous tannery solid waste for the production of extracellular acidic protease by Selenomonas ruminantium

“…Similarly, the pH stability of the enzyme determined by measurement of the relative activity after incubation at various pH revealed that the enzyme was also found to be stable in pH 4, which leads to the confirmation that the purified enzyme is an acid protease. Similar results were observed in protease production by Saccharomyces lipolytica and Mucor pusillus (Tetsuji and Ogrydziak, 1983;Somkuti and Babel, 1968), which had the optimum pH for protease activity to be around 4. The activity declined with further increase or decrease in the pH.…”

Purification and characterization of protease enzymes of Basidiobolus and Conidiobolus species

“…These two important characteristics of the proteases probably account partly for the wide ecological and geographical distribution of these fungi. The protease of Rhizomucorpusillus, was also optimally active at p H 5.4-5.6 when casein was used as substrate but much less so when acid-denatured haemoglobulin was used [ 3 ] . This result compares favourably with the present work, in which the optimum pH for protease activity of the Basidiobolus and Conidiobolus species was 5.5 when casein was used as substrate.…”

“…The dissolved protease obtained from each of the test isolates was purified further by chromatography using the modified methods of Somkuti & Babel [3] and Diamond & Denman [4]. Sephadex G-100 powder was allowed to swell in excess solvent (0.1 M sodium acetate buffer, pH 5.5) in a dark cupboard for 3 days.…”