Type C feruloyl esterase from Aspergillus ochraceus: a butanol specific biocatalyst for the synthesis of hydroxycinnamates in a ternary solvent system
Electron. j. biotechnol
;
35: 1-9, sept. 2018. graf, tab
Article
in English
| LILACS
| ID: biblio-1047456
ABSTRACT
Background:
Aspergillus ochraceus was isolated from coffee pulp and selected as an interesting hydroxycinnamoyl esterase strain producer, using an activity microplate high-throughput screening method. In this work, we purified and characterized a new type C A. ochraceus feruloyl esterase (AocFaeC), which synthesized specifically butyl hydroxycinnamates in a ternary solvent system.Results:
AocFaeC was produced by solid state fermentation, reaching its maximal activity (1.1 U/g) after 48 h of culture. After purification, the monomeric protein (34 kDa) showed a specific activity of 57.9 U/mg towards methyl ferulate. AocFaeC biochemical characterization confirmed its identity as a type C feruloyl esterase and suggested the presence of a catalytic serine in the active site. Its maximum hydrolytic activity was achieved at 40°C and pH 6.5 and increased by 109 and 77% with Ca2+ and Mg2+, but decreased by 90 and 45% with Hg2+ and Cu2+, respectively. The initial butyl ferulate synthesis rate increased from 0.8 to 23.7 nmol/min after transesterification condition improvement, using an isooctanebutanolwater ternary solvent system, surprisingly the synthesis activity using other alcohols was negligible. At these conditions, the synthesis specific activities for butyl p-coumarate, sinapinate, ferulate, and caffeate were 87.3, 97.6, 168.2, and 234 U/µmol, respectively. Remarkably, AocFaeC showed 5 folds higher butyl caffeate synthesis rate compared to type B Aspergillus niger feruloyl esterase, a well-known enzyme for its elevated activity towards caffeic acid esters.Conclusions:
Type C feruloyl esterase from A. ochraceus is a butanol specific biocatalyst for the synthesis of hydroxycinnamates in a ternary solvent system
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LILACS (Americas)
Main subject:
Aspergillus ochraceus
/
Carboxylic Ester Hydrolases
/
Coumaric Acids
Language:
English
Journal:
Electron. j. biotechnol
Journal subject:
Biotechnology
Year:
2018
Type:
Article
Affiliation country:
Mexico
Institution/Affiliation country:
Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, A.C/MX
/
Instituto Tecnológico de Sonora/MX
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