... data-base NCBInr using mascot (Matrix Science, Boston, MA,USA).Cloning, expression, and purification of FdxFdx (TTC1809) was amplified by PCR using genomic DNAas a template and two oligonucleotide ... condi-tions was determined by gel filtration on a Superdex-200HR column, which was calibrated using molecularmass standards and equilibrated with buffer A containing150 mm KCl. Gel filtration ... theoptimal reaction conditions, we assessed the effects of pH(4.0–7.4), Fdx (30–960 nm) and Tween 20 (0.1–1.6%) on b-carotene hydroxylation activity. The b-carotene hydrox-ylation reactions were carried...