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HASSAN, R., HAUKA, F., ISMAIL, I., SHADY, T. (1999). FAT HYDROLYSIS BY BACILLUS SUBTILIS LIPASE AND SOME PROPERTIES OF THIS ENZYME. Egyptian Journal of Agricultural Research, 77(1), 15-25. doi: 10.21608/ejar.1999.326134
RAMADAN A. HASSAN; FATHY A. HAUKA; ISMAIL I. ISMAIL; TAWFIK S.M. SHADY. "FAT HYDROLYSIS BY BACILLUS SUBTILIS LIPASE AND SOME PROPERTIES OF THIS ENZYME". Egyptian Journal of Agricultural Research, 77, 1, 1999, 15-25. doi: 10.21608/ejar.1999.326134
HASSAN, R., HAUKA, F., ISMAIL, I., SHADY, T. (1999). 'FAT HYDROLYSIS BY BACILLUS SUBTILIS LIPASE AND SOME PROPERTIES OF THIS ENZYME', Egyptian Journal of Agricultural Research, 77(1), pp. 15-25. doi: 10.21608/ejar.1999.326134
HASSAN, R., HAUKA, F., ISMAIL, I., SHADY, T. FAT HYDROLYSIS BY BACILLUS SUBTILIS LIPASE AND SOME PROPERTIES OF THIS ENZYME. Egyptian Journal of Agricultural Research, 1999; 77(1): 15-25. doi: 10.21608/ejar.1999.326134

FAT HYDROLYSIS BY BACILLUS SUBTILIS LIPASE AND SOME PROPERTIES OF THIS ENZYME

Article 2, Volume 77, Issue 1, March 1999, Page 15-25  XML PDF (2.55 MB)
Document Type: Original Article
DOI: 10.21608/ejar.1999.326134
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Authors
RAMADAN A. HASSAN1; FATHY A. HAUKA1; ISMAIL I. ISMAIL1; TAWFIK S.M. SHADY2
1Department of Microbiology, and Agriculture Chemistry, Faculty of Agriculture, Mansoura University, Mansou‌ra, Egypt
2Agricultural Microbiology Research Department, Soils, Water and Environment Institute, Agricultural Research Center, Giza, Egypt
Abstract
The best saturation for lipase precipitation by ammonium sul­phate was found to be 0.8, which gave the highest yield, being 90.9% with specific activity and degree of purification of 70.1 p.mol FFA/mg protein/min. and 8.75 folds, respectively. By using 0.8 saturation of am­monium sulphate, pH 6.0 was found as the best pH value for enzyme precipitation. The yield of lipase at such pH value was 76.36%. The ef­fects of pH and temperature on lipase activity varied with the substrate. The optimum pH was in the range of pH 7.9; the optimum temperature was in the range 40-50°C in case of olive oil which was the best tested substrate. The pH stability curve at 4oC showed no discontinuities and had a maximum between pH 6.0 and 8.0 at 1, 24 and 48 hrs. Also at 21-50°C, the residual activity reached 88.1% and 47.6%, respectively. Moreover after 48 hrs, the residual activity showed 71.4 and 35.7%. re­spectively. The enzyme lost very little activity between 30-50°C and was also quite stable at 60°C, but it lost activity very rapidly at 80°C. The hydrolysis of oils by Bacillus subtilis lipase was also studied and the degree of hydrolysis at 40°C reached after 24 hrs 92.11, 84.62 and 79.79%, for olive, palm and coconut oils, respectively.
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