Aspergillus niger mediated a-hydroxylation of cyclic ketones

Download

index.pdf

Date

2006

Author

Karabacak, Elife Özlem

Metadata

Show full item record

Item Usage Stats

230
views

102
downloads

Chiral a -hydroxy ketones are important structural units in many natural products, biologically active compounds and the hydroxyl group has frequently been used as a reagent directing group, such as for the selective elaboration of aldol products. In this work, enzymatic synthesis of both enantiomers of the a -hydroxy ketones (2-hydroxy indanone, 2-hydroxy tetralone) using Aspergillus niger by selective α-oxidation of ketones (1-indanone, 1-tetralone) was studied. The α-oxidation of ketones was carried out by using whole cells of Aspergillus niger in different growth media. A. niger whole cell catalyzed reactions afforded (S)-configurated 2- hydroxy-1-tetralone with %87 e.e. in DMSO at pH 5.0. In addition to this,while (S)-configurated 2-hydroxy-1-indanone with %33 e.e. in pH 8.0 (in DMSO) was synthesized, (R)-configurated-2-hyroxy-1-indanone with %32 e.e. in pH 7.0 ( in DMSO) was synthesized.

Subject Keywords

Biotechnology.

URI

http://etd.lib.metu.edu.tr/upload/3/12608088/index.pdf
https://hdl.handle.net/11511/16485

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Determination of metabolic bottlenecks using reaction engineering principles in serine alkaline protease production by recombinant bacillus sp. Telli, İlkin Ece; Çalık, Pınar; Department of Chemical Engineering (2004) In this study, firstly, bioprocess characteristics for Serine Alkaline Protease (SAP) production, using recombinant Bacillus subtilis carrying pHV1431::subC, were examined. The cell concentration, substrate concentration, SAP activity and SAP synthesis rate profiles demonstrated that the system reaches to a steady state in terms of cell growth and SAP synthesis between t=15-25 h, therefore, this time interval is appropriate to employ both metabolic flux analysis and metabolic control analysis, which apply s...
Influence of oxygen transfer on benzaldehyde lyase production by recombinant Escherichia coli BL21(DE3) pLySs Angardi, Vahideh; Çalık, Pınar; Department of Chemical Engineering (2007) In this study, the effects of oxygen transfer conditions on the synthesis of the enzyme benzaldehyde lyase as intracellular in recombinant E. coli BL21 (DE3) pLysS was investigated sistematically and a comprehensive model was developed to determine benzaldehyde lyase activity. For this purpose, the research program was carried out in mainly two parts. In the first part of study, the effects of oxygen transfer together with the mass transfer coefficient (KLa), enhancement factor E (=KLa/KLao), volumetric oxy...
Recombinant therapeutic protease production by Bacillus sp. Korkmaz, Nuriye; Çalık, Pınar; Department of Chemical Engineering (2007) The first aim of this study is the development of extracellular recombinant therapeutic protease streptokinase producing Bacillus sp., and the second aim is to determine fermentation characteristics for streptokinase production. In this context, the signal (pre-) DNA sequence of B.licheniformis (DSM1969) extracellular serine alkaline protease enzyme gene (subC: Acc. No. X03341) was ligated to 5’ end of the streptokinase gene (skc: Acc. No. S46536) by SOE (Gene Splicing by Overlap Extension) method through P...
Production of recombinant proteins by yeast cells Celik, Eda; Çalık, Pınar (Elsevier BV, 2012-09-01) Yeasts are widely used in production of recombinant proteins of medical or industrial interest. For each individual product, the most suitable expression system has to be identified and optimized, both on the genetic and fermentative level, by taking into account the properties of the product, the organism and the expression cassette. There is a wide range of important yeast expression hosts including the species Saccharomyces cerevisiae, Pichia pastoris, Hansenula polymorpha, Kluyveromyces lactis, Schizosa...
Recombinant pyrococcus furiosus extracellular α-amylase expression in pichia pastoris Boy, Erdem; Çalık, Pınar; Department of Chemical Engineering (2011) Pyrococcus furiosus extracellular α-amylase is a hyperthermostable glucosyl hydrolyzing enzyme which shows unique biochemical properties that may have impact on improving starch hydrolysis process; however, it is insignificantly expressed in its native archaeal host. In this study, it was aimed to express the P. furiosus extracellular alpha-amylase (PFA) in Pichia pastoris, which is a well-recognized overexpression host used in production of heterologous proteins. In this context, first, P. furiosus was gro...

Citation Formats

E. Ö. Karabacak, “Aspergillus niger mediated a-hydroxylation of cyclic ketones,” M.S. - Master of Science, Middle East Technical University, 2006.