Production and characterization of a milk-clotting protease in the crude enzymatic extract from the newly isolated Thermomucor indicae-seudaticae N31: (Milk-clotting protease from the newly isolated Thermomucor indicae-seudaticae N31)

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• 作者：Carolina Merheb-Dini ; Eleni Gomes ; Maurí ; cio Boscolo ; Roberto da Silva
• 关键词：Thermophilic fungi ; SSF ; Protease ; Milk-clotting ; Urea– ; PAGE ; RP-HPLC
• 刊名：Food Chemistry
• 出版年：2010
• 出版时间：1 May 2010
• 年：2010
• 卷：120
• 期：1
• 页码：87-93
• 全文大小：395 K

文摘

Microbial rennet-like milk-clotting enzymes are aspartic proteinases that catalyze milk coagulation, substituting calf rennet. Crude enzymatic extract produced by the thermophilic fungus, Thermomucor indicae-seudaticae N31, on solid state fermentation (SSF) using wheat bran, exhibited high milk-clotting activity and low proteolytic activity after 24 h of fermentation. Highest milk-clotting activity (MCA) was at pH 5.7, at 70 °C and in 0.04 M CaCl₂; it was stable in the pH range 3.5–4.5 for 24 h and up to 45 °C for 1 h. MCA was highly inhibited by pepstatin A. Hydrolytic activity profile of the crude enzymatic extract on whole bovine casein, analyzed by gel electrophoresis (Urea–PAGE) and RP-HPLC revealed low proteolytic action towards casein fractions and a peptide profile similar to the one obtained with commercial Rhizomucor miehei protease (Hannilase).