Go to Top Go to Bottom
Animal Products
Asian-Australasian Journal of Animal Sciences 2010;23(10): 1369-1379.
DOI: https://doi.org/10.5713/ajas.2010.80694    Published online August 20, 2010.
Comparison of Milk-clotting Activity of Proteinase Produced by Bacillus Subtilis var, natto and Rhizopus oligosporus with Commercial Rennet
Ming Tsao Chen, Ying Yu Lu, Tien Man Weng
This study investigated purification and milk-clotting activity of the enzymes produced by Bacillus subtilis var, natto and Rhizopus oligosporus compared with that of commercial rennet. The clotting time, viscosity, tension and microstructure of the curd and electrophoretic patterns of milk proteins were determined. The milk-clotting activity/proteolytic activity ratios (MCA/PA ratio) of B. subtilis, R. oligosporus and commercial rennet were also compared. The results revealed that the curd formed by the commercial rennet had the highest viscosity and curd tension and the shortest clotting time among the three enzymes. However, curd produced by Rhizopus enzymes was ranked as second. From the MCA/PA ratio and electrophoretogram analyses it could be concluded that the enzyme produced by B. subtilis had the highest proteolytic activity, while the commercial rennet had the highest milk-clotting activity. Observations of microstructures of SEM showed that the three-dimensional network for curd formed by commercial rennet was denser, firmer and more smooth. The milk-clotting activity, specific activity, purification ratio and recovery of the purified enzymes produced by both the tested organisms were also determined with ion exchange chromatography and gel filtration.
Keywords: Microbial Rennet; Milk Clotting; Bacillus subtilis; Rhizopus oligosporus; Purification
METRICS Graph View
  • 5 Crossref
  • 5 Scopus
  • 2,369 View
  • 14 Download
Related articles

Editorial Office
Asian-Australasian Association of Animal Production Societies(AAAP)
Room 708 Sammo Sporex, 23, Sillim-ro 59-gil, Gwanak-gu, Seoul 08776, Korea   
TEL : +82-2-888-6558    FAX : +82-2-888-6559   
E-mail : jongkha@hotmail.com               

Copyright © 2020 by Asian-Australasian Journal of Animal Sciences. All rights reserved.

Close layer
prev next