The purification and activities of an alkaline protease of Aspergillus clavatus from Nigerian poultry feeds

✍ Scribed by Dr. V. W. Ogundero; S. O. Osunlaja

• Publisher: John Wiley and Sons
• Year: 1986
• Tongue: English
• Weight: 434 KB
• Volume: 26
• Category: Article
• ISSN: 0233-111X
• DOI: 10.1002/jobm.3620260415

✦ Synopsis

Optimal growth and extracellular protease production by Aspergillus clawatus Des. was recorded a t 30 O C and between days 5 and 7 of the %day incubation period. Purification of this enzyme was achieved by a combination of ultrafiltration, alcoholic precipitation and fractionation on DEAEcellulose and Sephadex-G.200. A single peak of an alkaline protease was subsequently obtained with a 9-fold increase in specific activity and a final recovery value of 26.2%.

The enzyme had optimal activity a t 37 "C and a pH of 7.8. The enzyme did not degrade leucine nmide, hippurylphenylalanine and hippurylarginine indicating lack of exo-protease activity. However, endo-protease activity led to a rapid hydrolysis of gelatin with optimal activity a t 40 "C and pH 7.8. The high incidence of A . clavatus on Nigerian poultry feeds vis-a-vis the potential health risks posed to farm animals is discussed.