title: Microbicidal action of photoirradiated aqueous extracts from wine lees.
abstract: Wine lees, a major waste product of winemaking, is a rich source of polyphenolic compounds. LED-light irradiation at 400-nm elicited microbicidal activity of aqueous extract from wine lees (WLE) againstStaphylococcus aureus,Pseudomonas aeruginosa, andCandida albicans, in addition to reactive oxygen species (ROS) formation, including hydroxyl radical (·OH) and hydrogen peroxide (H2O2). Although treatment for 20 min of photoirradiation alone exerted bactericidal activity with a 2- to 3-log reduction, photoirradiated WLE for 20 min achieved a 5-log or greater reduction in viableS. aureusandP. aeruginosacells. RegardingC. albicans, a 1-log reduction (90 % reduction) of viable cells was achieved by photoirradiated WLE for 40 min, whereas photoirradiation alone did not show any fungicidal effect. ROS analyses revealed that approximately 170 μM ·OH and 600 μM H2O2were generated in photoirradiated WLE for 20 min. Because the bactericidal activity of photoirradiated WLE was abolished by ·OH scavengers, ROS, especially highly oxidative ·OH, may be responsible for the microbicidal activity of photoirradiated WLE. In addition to its microbicidal activity, WLE may act as an antioxidant as it exerted radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl, a stable free radical.
authors.affiliation: Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 2-12-1-M6-7 Ookayama, Meguro-ku, Tokyo, 152-8250 Japan ; HABA Laboratories Inc., 1-24-11, Kanda Sudacho, Chiyoda-ku, Tokyo, 101-0041 Japan.
authors.forename: Mana
authors.initials: M
authors.lastname: Tsukada
authors.affiliation: Tohoku University Graduate School of Dentistry, 4-1 Seiryo, Aoba-ku, Sendai, 980-8575 Japan.
authors.forename: Hong
authors.initials: H
authors.lastname: Sheng
authors.affiliation: Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 2-12-1-M6-7 Ookayama, Meguro-ku, Tokyo, 152-8250 Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Kamachi
authors.affiliation: Tohoku University Graduate School of Dentistry, 4-1 Seiryo, Aoba-ku, Sendai, 980-8575 Japan.
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Niwano
keywords: Hydrogen peroxide; Hydroxyl radical; Microbicidal action; Wine lees