Scanning electron microscopic studies of lipase-catalysed esterification catalysis for the synthesis of stearoyl lactate and p-cresyl laurate.

Suresh Babu, C. V. and Kiran, K. R. and Divakar, S. (2001) Scanning electron microscopic studies of lipase-catalysed esterification catalysis for the synthesis of stearoyl lactate and p-cresyl laurate. World Journal of Microbiology and Biotechnology, 17 (7). 659-665, 19 ref..

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Abstract

The state of 3 immobilized lipases, 2 from Rhizomucor miehei and 1 from porcine pancreas, used in esterification reactions for production of food additive esters, was investigated by SEM. All 3 lipases, which were subjected to high temp. and non-polar solvents for a prolonged period of incubation of 72-120 h, showed decreases in 'compactness' when compared with the fresh enzymes. The presence of buffer preserved the activity and compactness, while its absence reduced the amount of enzyme/unit area on the support. R. miehei lipase samples incubated in the presence of 0.0004 ml of 0.1M buffer/mg enzyme at different pH values (4.0-9.0) showed a decrease in compactness on the surface, which correlated to an increase in esterification activity. An increase in buffer vol. (0.0002-0.003 ml/mg enzyme) in the reaction mixture at pH 7.0 decreased compactness and reduced activity. Results indicate that a compromise between pH and buffer vol. can lead to variations in the extent of adsorption, distribution and activity, enabling max. conversions in esterification reactions.

Item Type:	Article
Uncontrolled Keywords:	ELECTRON-MICROSCOPY; ESTERIFICATION-; IMMOBILIZED-ENZYMES; LIPASES-; PH-; RHIZOMUCOR-; CONFORMATION-; RHIZOMUCOR-MIEHEI; SEM-
Subjects:	500 Natural Sciences and Mathematics > 04 Chemistry and Allied Sciences > 07 Microscopic Analysis
Divisions:	Fermentation Technology and Bioengineering
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	30 Jun 2009 11:55
Last Modified:	28 Dec 2011 09:59
URI:	http://ir.cftri.res.in/id/eprint/7612

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