Milk-clotting and proteolytic activities of rennet, and of bovine pepsin and porcine pepsin

1969 ◽  
Vol 36 (3) ◽  
pp. 427-433 ◽  
Author(s):  
P. F. Fox
Keyword(s):  
Porcine Pepsin ◽  
Milk Clotting ◽  
Proteolytic Activities ◽  
Ph Dependent ◽  
Rapid Drop ◽  
Milk Clotting Activity

SummaryThe milk-clotting and proteolytic activities of rennet, bovine pepsin and porcine pepsin were compared. The milk-clotting activity of porcine pepsin was extremely pH-dependent around pH 6·6 and coagulation did not occur above pH 6·68. The clotting activity of bovine pepsin was slightly more dependent on pH than that of rennet but no rapid drop-off in activity occurred as with porcine pepsin. Temperature influenced the clotting activity of rennet and bovine pepsin similarly but the behaviour of porcine pepsin was markedly different.For equal milk-clotting activity, the proteolytic activities of rennet and bovine pepsin were approximately equal and substantially lower than that of porcine pepsin. Electrophoretic examination showed that the proteolysis products of rennet and bovine pepsin were similar and quite different from those produced by porcine pepsin.The suitability of bovine pepsin as a rennet substitute is discussed.

A novel milk-clotting enzyme from Aspergillus oryzae and A. luchuensis is an aspartic endopeptidase PepE presumed to be a vacuolar enzyme

2022 ◽  
Author(s):  
Yoko Takyu ◽  
Taro Asamura ◽  
Ayako Okamoto ◽  
Hiroshi Maeda ◽  
Michio Takeuchi ◽  
...  
Keyword(s):  
Aspergillus Oryzae ◽  
Milk Clotting ◽  
Milk Clotting Enzyme ◽  
Proteolytic Activities ◽  
Homologous Enzyme ◽  
Traditional Fermentation ◽  
Enzyme Source ◽  
Cheese Production ◽  
Milk Clotting Activity ◽  
Aspartic Endopeptidase

Abstract Aspergillus oryzae RIB40 has 11 aspartic endopeptidase genes. We searched for milk-clotting enzymes based on the homology of the deduced amino acid sequence with chymosins. As a result, we identified a milk-clotting enzyme in A. oryzae. We expected other Aspergillus species to have a homologous enzyme with milk-clotting activity, and we found the most homologous aspartic endopeptidase from A. luchuensis had milk-clotting activity. Surprisingly, two enzymes were considered as vacuole enzymes according to a study on A. niger proteases. The two enzymes from A. oryzae and A. luchuensis cleaved a peptide between the 105Phe-106Met bond in κ-casein, similar to chymosin. Although both enzymes showed proteolytic activity using casein as a substrate, the optimum pH values for milk-clotting and proteolytic activities were different. Furthermore, the substrate specificities were highly restricted. Therefore, we expected that the Japanese traditional fermentation agent, koji, could be used as an enzyme source for cheese production.

Milk clotting activity and production of bioactive peptides from whey using Maclura pomifera proteases

LWT ◽  
2012 ◽  
Vol 47 (1) ◽  
pp. 103-109 ◽  
Author(s):  
Maria Alicia Corrons ◽  
Juan Ignacio Bertucci ◽  
Constanza Silvina Liggieri ◽  
Laura María Isabel López ◽  
Mariela Anahí Bruno
Keyword(s):  
Bioactive Peptides ◽  
Maclura Pomifera ◽  
Milk Clotting ◽  
Milk Clotting Activity
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