Assessment of Purified Bacterial Milk Clotting Enzyme from Bacillus subtilis K-26 for Cheddar Cheese Making

The influence of substitutions of amino acids involved in the formation of salt bridges on the cow chymosin technological properties has been studied. It was shown that point amino acid mutations Asp198→Lys, Asp156→Val and their combination decrease the sensitivity of coagulation activity of engineering recombinant chymosins to change in the concentration of calcium chloride in milk in the range of 1-5 mM. The found effect is a positive technological evidence in terms of cheese making, since it allows varying the content of calcium chloride added to the milk mixture without a threat of significant changes in the undesired proteolytic activity of used milk-clotting enzyme. recombinant chymosin, technological properties, amino acid substitutions, milk-clotting activity, concentration of calcium chloride. The work was performed within the framework of the state task of the Ministry of science and higher education of the Russian Federation (topic number fzmw-2020-0002, "Development of recombinant enzyme producers for cheese making").

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Optimization of the production and characterization of milk-clotting enzyme from Bacillus subtilis isolated from marine sponge

Egyptian Pharmaceutical Journal ◽

10.4103/1687-4315.197584 ◽

2016 ◽

Vol 15 (3) ◽

pp. 158 ◽

Cited By ~ 2

Author(s):

HalaR Wehaidy ◽

MohamedA Abdel-Naby ◽

WafaaG Shousha ◽

MohammedI.Y. El Mallah ◽

MichaelM Shawky

Keyword(s):

Bacillus Subtilis ◽

Marine Sponge ◽

Milk Clotting ◽

Milk Clotting Enzyme

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Assessment of swine, bovine and chicken pepsins as rennet substitutes for Cheddar cheese-making

Journal of Dairy Research ◽

10.1017/s0022029900014096 ◽

1972 ◽

Vol 39 (2) ◽

pp. 261-273 ◽

Cited By ~ 29

Author(s):

Margaret L. Green

Keyword(s):

Cheddar Cheese ◽

Cheese Making ◽

Stomach Mucosa ◽

Milk Clotting ◽

Cheese Ripening ◽

Cheese Flavour ◽

The Cost ◽

Substrate Ph ◽

Milk Clotting Activity

SummaryThree enzymes were assessed as rennet substitutes for cheese-making. The bovine and chicken pepsins used were relatively crude extracts of bovine stomach mucosa and chicken proventriculae respectively; the swine pepsin was a partially purified commercial product. The ratios of milk-clotting activity to general proteolytic activity were high for rennet and bovine pepsin and low for swine and chicken pepsins. Both bovine mucosa and chicken stomach gave low milk-clotting activities compared with calf stomach. For all the enzymes the chemical reactions causing milk clotting appeared to be the same. The milk-clotting activity showed a decrease with increase in substrate pH for all the enzymes, although they were all still active at pH 6·81.Duplicate cheeses were made from each of the swine, bovine and chicken pepsins, with rennet as a standard in each trial. The cheese-making process was similar with each enzyme, but differences appeared during ripening. The chicken-pepsin cheeses had poor body and weak Cheddar-cheese flavour, with many and intense off-flavours. The cheeses made with bovine and swine pepsins were only slightly inferior in quality and intensity of Cheddar-cheese flavour to the rennet cheeses. From a simulated cheese-making experiment it was concluded that 30–40 % of the added rennet, bovine pepsin and chicken pepsin was probably inactivated during the cheese-making process and that most or all of the swine pepsin was lost. These results provide an explanation for the variations observed in cheese ripening.It was concluded that chicken pepsin would not prove a suitable rennet substitute for making Cheddar cheese because of the quality of the cheese produced, and that bovine pepsin would not prove suitable because of the cost of preparing a suitable extract. Swine pepsin would appear to be suitable if the ripening time were to be lengthened or if another enzyme were to be added to assist ripening; it is cheaper than rennet and other rennet substitutes.

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