Linked Life Data

11064332

Source:http://linkedlifedata.com/resource/pubmed/id/11064332

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2000-12-11
pubmed:abstractText
Microemulsions provide an interesting alternative to classical methods for the conversion of less water-soluble substrates by alcohol dehydrogenase, but until now stability and activity were too low for economically useful processes. The activity and stability of the enzymes are dependent on the microemulsion composition, mostly the water and the surfactant concentration. Therefore, it is necessary to know the exact phase behavior of a given microemulsion reaction system and the corresponding enzyme behavior therein. Because of their economic and ecologic suitability polyethoxylated fatty alcohols were investigated concerning their phase behavior and their compatibility with enzymes in ternary mixtures. The phase behavior of Marlipal O13-60 (C13EO6 in industrial quality)/cyclohexane/water and its effect on the activity and stability of alcohol dehydrogenase from Yeast (YADH) and horse liver (HLADH) and the carbonyl reductase from Candida parapsilosis (CPCR) is presented in this study. Beside the macroscopic phase behavior of the reaction system, the viscosity of the system indicates structural changes of aggregates in the microemulsion. The changes of the enzyme activities with the composition are discussed on the basis of transitions from reverse micelles to swollen reverse micelles and finally, the transition to the phase separation. The formate dehydrogenase from Candida boidinii was used for the NADH-regeneration during reduction reactions. While the formate dehydrogenase did not show any kinetic effect on the microemulsion composition, the other enzymes show significant changes of activity and stability varying the water or surfactant concentration of the microemulsion. Under certain conditions, stability could be maintained with HLADH for several weeks. Successful experiments with semi-batch processes including cofactor regeneration and product separation were performed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-3592
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
70
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
638-46
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Stability and activity of alcohol dehydrogenases in W/O-microemulsions: enantioselective reduction including cofactor regeneration.
pubmed:affiliation
Institut für Technische Chemie, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Federal Republic of Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't