title: Asymmetric synthesis of (S)-ethyl-4-chloro-3-hydroxybutanoate using Candida parapsilosis ATCC 7330.
abstract: Asymmetric reduction of ethyl-4-chloro-3-oxobutanoate to (S)-ethyl-4-chloro-3-hydroxybutanoate in aqueous medium by resting cells of Candida parapsilosis ATCC 7330 was optimized. The influence of culture parameters (inoculum size, inoculum age and biocatalyst harvest time) and reaction parameters (co-substrate, resting cell, pH and substrate concentrations) on the asymmetric reduction were studied. It was found that these parameters significantly influenced the rate of the asymmetric reduction. Under the optimum conditions, the final concentration of (S)-ethyl-4-chloro-3-hydroxybutanoate, enantiomeric excess and the isolated yield of (S)-ethyl-4-chloro-3-hydroxybutanoate were 1.38 M (230 g/l), >99 and 95%, respectively. The space time yield was 115 mmol/lh, which is significantly higher than other whole cell biocatalysts reported so far.
authors.affiliation: Department of Biotechnology, Indian Institute of Technology-Madras, Chennai, India.
authors.forename: Tarjan
authors.initials: T
authors.lastname: Kaliaperumal
authors.forename: S
authors.initials: S
authors.lastname: Kumar
authors.forename: Sathyanarayana N
authors.initials: SN
authors.lastname: Gummadi
authors.forename: Anju
authors.initials: A
authors.lastname: Chadha
mesh_terms: D000090:Acetoacetates / Q000378:metabolism; D002087:Butyrates / Q000378:metabolism*; D002175:Candida / Q000235:genetics / Q000378:metabolism*; D003470:Culture Media; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology; D013696:Temperature
chemical_list: D000090:Acetoacetates; D002087:Butyrates; D003470:Culture Media; C121244:ethyl 4-chloro-3-hydroxybutanoate; C111982:ethyl 4-chloro-3-oxobutanoate; D005947:Glucose