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Bioconversion of a L-carnitin precursor in a one- or two-phase system
G Bare1, P Jacques, J B Hubert
1Centre Wallon de Biologie Industrielle, Université de Liège, Belgium.
Applied Biochemistry and Biotechnology
|January 1, 1991
Summary
Saccharomyces cerevisiae efficiently bioconverts octyl-4-chloroacetoacetate (OCA) into a precursor for L-carnitine. Free yeast cells in a monophasic system achieved over 90% conversion, highlighting its potential in chiral alcohol synthesis.
Area of Science:
- Biotechnology
- Enzymatic Bioconversion
- Organic Synthesis
Background:
- L-carnitine is a vital physiological agent.
- Chiral alcohols are crucial precursors in pharmaceutical synthesis.
- Stereoselective bioconversion offers a sustainable route to chiral compounds.
Purpose of the Study:
- To investigate the stereoselective bioconversion of octyl-4-chloroacetoacetate (OCA) using Saccharomyces cerevisiae.
- To evaluate the efficiency of free and immobilized yeast cells in different reaction systems.
- To identify factors limiting bioconversion efficiency.
Main Methods:
- Utilized Saccharomyces cerevisiae for the bioconversion of octyl-4-chloroacetoacetate (OCA).
- Compared bioconversion efficiency in monophasic and two-phase systems.
- Assessed the performance of free cells versus immobilized cells in alginate beads.
- Investigated the impact of substrate concentration on conversion rates.
Main Results:
- Free Saccharomyces cerevisiae cells achieved over 90% bioconversion of 0.018 M OCA in a monophasic system within 6 hours, with high enantiomeric excess (eeR:97%).
- Immobilized cells showed lower efficiency compared to free cells in both monophasic and two-phase systems.
- In a two-phase system, free cells converted 85% of 0.018 M OCA in 48 hours, and 41% of a higher concentration (0.270 M) in the same period.
- Cofactor regeneration was identified as a limiting factor in two-phase reactors with immobilized cells.
Conclusions:
- Saccharomyces cerevisiae is a highly effective biocatalyst for the stereoselective production of chiral alcohols from OCA.
- Monophasic systems with free cells offer superior efficiency for OCA bioconversion.
- Further optimization is needed to enhance the performance of immobilized cells and two-phase systems, particularly concerning cofactor regeneration.