FIG 9.

Hydroxycinnamate reductase activity in lactic acid bacteria. (A) PCR amplification of the HcrB gene. Chromosomal DNA from several lactic acid bacteria was used for PCR amplification with oligonucleotides 1655 and 1656 to amplify 1.4 kb of the hcrB gene. PCR products were subjected to gel electrophoresis and stained with Gel Red. Left lane, λ/EcoT14I (TaKaRa) molecular size marker. Numbers indicate some of the molecular sizes. (B) HPLC chromatograms of supernatants from lactic acid bacteria grown for 10 days at 30°C in MRS medium supplemented with 1.5 mM m-coumaric acid. The m-coumaric acid (mCA) and 3-(3-hydroxyphenyl)propionic acid (3-HPPA) detected are indicated. Chromatograms were recorded at 280 nm. The strains assayed were Enterococcus casseliflavus DSM 20680 (1), E. durans DSM 20633 (2), E. faecalis DSM 20478 (3), E. faecium CECT 4102 (4), E. gallinarum DSM 24841 (5), E. hirae DSM 20160 (6), Lactobacillus brevis CECT 5354 (7), L. fermentum CECT 4007 (8), L. fructivorans CECT 4785 (9), L. paraplantarum DSM 10641 (10), L. plantarum subsp. argentoratensis DSM 16365 (11), L. plantarum subsp. plantarum ATCC 14917 (CECT 748) (12), L. plantarum DSM 10492 (13), L. pentosus DSM 16366 (14), L. sakei subsp. carnosus DSM 15831 (15), Leuconostoc citreum CECT 4025 (16), and Streptococcus gallolyticus UCN34 (17).