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Water activity and substrate concentration effects on lipase activity.

Wehtje, Ernst LU and Adlercreutz, Patrick LU (1997) In Biotechnology and Bioengineering 55(5). p.798-806
Abstract
Catalytic activity of lipases (from Rhizopus arrhizus, Canadida rugosa, and Pseudomonas sp. was studied in organic media, mainly diisopropyl ether. The effect of water activity (a(w)) on V(max) showed that the enzyme activity in general increased with increasing amounts of water for the three enzymes. This was shown both for esterification and hydrolysis reactions catalyzed by R. arrhizus lipase. In the esterification reaction the K(m) for the acid substrate showed a slight increase with increasing water activities. On the other hand, the K(m) for the alcohol substrate increased 10-20-fold with increasing water activity. The relative changes in K(m) were shown to be independent of the enzyme studied and solvent used. The effect was... (More)
Catalytic activity of lipases (from Rhizopus arrhizus, Canadida rugosa, and Pseudomonas sp. was studied in organic media, mainly diisopropyl ether. The effect of water activity (a(w)) on V(max) showed that the enzyme activity in general increased with increasing amounts of water for the three enzymes. This was shown both for esterification and hydrolysis reactions catalyzed by R. arrhizus lipase. In the esterification reaction the K(m) for the acid substrate showed a slight increase with increasing water activities. On the other hand, the K(m) for the alcohol substrate increased 10-20-fold with increasing water activity. The relative changes in K(m) were shown to be independent of the enzyme studied and solvent used. The effect was attributed to the increasing competition of water as a nucleophile for the acyl-enzyme at higher water activities. In a hydrolysis reaction the K(m) for the ester was also shown to increase as the water activity increased. The effect of water in this case was due to the fact that increased concentration of one substrate (water), and thereby increased saturation of the enzyme, will increase the apparent K(m) of the substrate (ester) to be determined. This explained why the hydrolysis rate decreased with increasing water activity at a fixed, low ester concentration. The apparent V(max) for R. arrhizus lipase was similar in four of six different solvents that were tested; exceptions were toulene and trichloroethylene, which showed lower values. The apparent K(m) for the alcohol in the solvents correlated with the hydrophobicity of the solvent, hydrophobic solvents giving lower apparent K(m). (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 55: 798-806, 1997. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Biotechnology and Bioengineering
volume
55
issue
5
pages
798 - 806
publisher
John Wiley & Sons
external identifiers
  • pmid:18636590
  • scopus:0031554889
ISSN
1097-0290
DOI
10.1002/(SICI)1097-0290(19970905)55:5<798::AID-BIT10>3.0.CO;2-8
language
English
LU publication?
yes
id
832e8040-579e-40f6-ac86-b7c383749b4c (old id 1181046)
date added to LUP
2008-10-10 12:53:42
date last changed
2017-10-22 03:48:57
@article{832e8040-579e-40f6-ac86-b7c383749b4c,
  abstract     = {Catalytic activity of lipases (from Rhizopus arrhizus, Canadida rugosa, and Pseudomonas sp. was studied in organic media, mainly diisopropyl ether. The effect of water activity (a(w)) on V(max) showed that the enzyme activity in general increased with increasing amounts of water for the three enzymes. This was shown both for esterification and hydrolysis reactions catalyzed by R. arrhizus lipase. In the esterification reaction the K(m) for the acid substrate showed a slight increase with increasing water activities. On the other hand, the K(m) for the alcohol substrate increased 10-20-fold with increasing water activity. The relative changes in K(m) were shown to be independent of the enzyme studied and solvent used. The effect was attributed to the increasing competition of water as a nucleophile for the acyl-enzyme at higher water activities. In a hydrolysis reaction the K(m) for the ester was also shown to increase as the water activity increased. The effect of water in this case was due to the fact that increased concentration of one substrate (water), and thereby increased saturation of the enzyme, will increase the apparent K(m) of the substrate (ester) to be determined. This explained why the hydrolysis rate decreased with increasing water activity at a fixed, low ester concentration. The apparent V(max) for R. arrhizus lipase was similar in four of six different solvents that were tested; exceptions were toulene and trichloroethylene, which showed lower values. The apparent K(m) for the alcohol in the solvents correlated with the hydrophobicity of the solvent, hydrophobic solvents giving lower apparent K(m). (c) 1997 John Wiley &amp; Sons, Inc. Biotechnol Bioeng 55: 798-806, 1997.},
  author       = {Wehtje, Ernst and Adlercreutz, Patrick},
  issn         = {1097-0290},
  language     = {eng},
  number       = {5},
  pages        = {798--806},
  publisher    = {John Wiley & Sons},
  series       = {Biotechnology and Bioengineering},
  title        = {Water activity and substrate concentration effects on lipase activity.},
  url          = {http://dx.doi.org/10.1002/(SICI)1097-0290(19970905)55:5<798::AID-BIT10>3.0.CO;2-8},
  volume       = {55},
  year         = {1997},
}