Esterification reactions catalyzed by lipases in microemulsions: The role of enzyme localization in relation to its selectivity

Stamatis, H; Xenakis, A; Provelegiou, M; Kolisis, FN

dc.contributor.author	Stamatis, H	en
dc.contributor.author	Xenakis, A	en
dc.contributor.author	Provelegiou, M	en
dc.contributor.author	Kolisis, FN	en
dc.date.accessioned	2014-03-01T01:09:24Z
dc.date.available	2014-03-01T01:09:24Z
dc.date.issued	1993	en
dc.identifier.issn	0006-3592	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/10955
dc.subject	esterifications	en
dc.subject	lipases	en
dc.subject	microemulsions	en
dc.subject	reverse micelles	en
dc.subject	selectivity	en
dc.subject.classification	Biotechnology & Applied Microbiology	en
dc.subject.other	Catalysis	en
dc.subject.other	Catalyst selectivity	en
dc.subject.other	Emulsions	en
dc.subject.other	Esterification	en
dc.subject.other	Fatty acids	en
dc.subject.other	Fluorescence	en
dc.subject.other	Micelles	en
dc.subject.other	Spectroscopic analysis	en
dc.subject.other	Structure (composition)	en
dc.subject.other	Enzyme localization	en
dc.subject.other	Lipases	en
dc.subject.other	Penicillium simplicissimum	en
dc.subject.other	Reverse micelles	en
dc.subject.other	Rhizopus arrhizus	en
dc.subject.other	Rhizopus delemar	en
dc.subject.other	Enzymes	en
dc.subject.other	triacylglycerol lipase	en
dc.subject.other	article	en
dc.subject.other	emulsion	en
dc.subject.other	enzyme localization	en
dc.subject.other	esterification	en
dc.subject.other	micelle	en
dc.subject.other	nonhuman	en
dc.subject.other	Penicillium simplicissimum	en
dc.subject.other	Rhizopus oryzae	en
dc.title	Esterification reactions catalyzed by lipases in microemulsions: The role of enzyme localization in relation to its selectivity	en
heal.type	journalArticle	en
heal.identifier.primary	10.1002/bit.260420114	en
heal.identifier.secondary	http://dx.doi.org/10.1002/bit.260420114	en
heal.language	English	en
heal.publicationDate	1993	en
heal.abstract	The activity of lipases from Rhizopus delemar, Rhizopus arrhizus, and Penicillium simplicissimum entrapped in microemulsions formulated by bis-(2-ethylhexyl)sulfosuccinate sodium salt (AOT) in isooctane has been studied in esterification reactions of various aliphatic alcohols with fatty acids. The effect of the nature of the fatty acids (chain length) and of the alcohols (primary, secondary, or tertiary; chain length; cyclic structures) on the lipase activities was investigated in relation to the reverse micellar structure. The lipases tested showed a selectivity regarding the structure of the substrates used when hosted in the AOT/isooctane microemulsion systems. Penicillium simplicissimum lipase showed higher reaction rates in the esterification of long chain alcohols as well as secondary alcohols. Primary alcohols had a low reaction rate and tertiary a very slow rate of esterification. Long chain fatty acids were better catalyzed as compared to the shorter ones. Rhizopus delemar and R. arrhizus lipases showed a preference for the esterification of short chain primary alcohols, while the secondary alcohols had a low rate of esterification and the tertiary ones could not be converted. The reaction of medium chain length fatty acids was also better catalyzed than in the case of the long ones. The observed lipase selectivity appeared to be related to the localization of the enzyme molecule within the micellar microstructure due to the hydrophobic/hydrophilic character of the protein. The reverse micellar structural characteristics, as well as the localization of the enzyme, were examined by fluorescence quenching measurements and spectroscopical studies.The activity of lipases from Rhizopus delemar, Rhizopus arrhizus, and Penicillium simplicissimum entrapped in microemulsions formulated by bis-(2-ethylhexyl)sulfosuccinate sodium salt (AOT) in isooctane has been studied in esterification reactions of various aliphatic alcohols with fatty acids. The effect of the nature of the fatty acids (chain length) and of the alcohols (primary, secondary, or tertiary; chain length; cyclic structures) on the lipase activities was investigated in relation to the reverse micellar structure. The lipases tested showed a selectivity regarding the structure of the substrates used when hosted in the AOT/isooctane microemulsion systems. Penicillium simplicissimum lipase showed higher reaction rates in the esterification of long chain alcohols as well as secondary alcohols. Primary alcohols had a low reaction rate and tertiary a very slow rate of esterification. Long chain fatty acids were better catalyzed as compared to the shorter ones. Rhizopus delemar and R. arrhizus lipases showed a preference for the esterification of short chain primary alcohols, while the secondary alcohols had a low rate of esterification and the tertiary ones could not be converted. The reaction of medium chain length fatty acids was also better catalyzed than in the case of the long ones. The observed lipase selectivity appeared to be related to the localization of the enzyme molecule within the micellar microstructure due to the hydrophobic/hydrophilic character of the protein. The reverse micellar structural characteristics, as well as the localization of the enzyme, were examined by fluorescence quenching measurements and spectroscopical studies.	en
heal.publisher	JOHN WILEY & SONS INC	en
heal.journalName	Biotechnology and Bioengineering	en
dc.identifier.doi	10.1002/bit.260420114	en
dc.identifier.isi	ISI:A1993LD31200013	en
dc.identifier.volume	42	en
dc.identifier.issue	1	en
dc.identifier.spage	103	en
dc.identifier.epage	110	en