Candida galli strain PGO6 isolated from oil-contaminated water is the first isolated yeast strain which is capable to form vanillin and vanillic acid during isoeugenol biotransformation. The products were confirmed by thin-layer chromatography (TLC), changes in the UV absorption pattern and high-performance liquid chromatography (HPLC). The phenotypic and physiochemical characteristics as well as molecular phylogenetic analysis based on amplification the ITS1–5.8S–ITS2 rDNA regions indicated the isolated strain PGO6 was identified as C. galli (GenBank accession number HM641231). Resting cells of C. galli PGO6 from the late-exponential of growth phase were used as biocatalysts for the biotransformation of isoeugenol. The optimal molar conversion of vanillin (48%) and vanillic acid (19%) was obtained after a 30 h incubation using 0.1% (v/v) of isoeugenol and 6 mg of dry weight of cells per ml without further optimization. Under these conditions, the total amount of vanillin and vanillic acid was 583 mg l−1. Further biotransformation was carried out using 0.5% (v/v) of isoeugenol under the resting cells conditions, yielding a vanillin concentration of 1.12 g l−1 (molar yield 25.7%) after 60 h incubation. This study brings the first evidence for biotransformation of isoeugenol to vanillin and vanillic acid by a yeast strain.
کلید واژگان :Biotransformation , Candida galli strain PGO6, Isoeugenol ,Vanillic acid , Vanillin
ارزش ریالی : 600000 ریال
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