title: A novel enzyme-based antimicrobial system comprising iodide and a multicopper oxidase isolated from Alphaproteobacterium strain Q-1.
abstract: Alphaproteobacterium strain Q-1 produces an extracellular multicopper oxidase (IOX), which catalyzes iodide (I-) oxidation to form molecular iodine (I2). In this study, the antimicrobial activity of the IOX/iodide system was determined. Both Gram-positive and Gram-negative bacteria tested were killed completely within 5 min by 50 mU mL(-1) of IOX and 10 mM iodide. The sporicidal activity of the system was also tested and compared with a common iodophor, povidone-iodine (PVP-I). IOX (300 mU mL(-1)) killed Bacillus cereus, B. subtilis, and Geobacillus stearothermophilus spores with decimal reduction times of 2.58, 7.62, and 40.9 min, respectively. However, 0.1% PVP-I killed these spores with much longer decimal reduction times of 5.46, 38.0, and 260 min, respectively. To evaluate the more superior sporicidal activity of the IOX system over PVP-I, the amount of free iodine (non-complexed I2) was determined by an equilibrium dialysis technique. The IOX system included more than 40 mg L(-1) of free iodine, while PVP-I included at most 25 mg L(-1) free iodine. Our results suggest that the new enzyme-based antimicrobial system is effective against a wide variety of microorganisms and bacterial spores, and that its strong biocidal activity is due to its high free iodine content, which is probably maintained by re-oxidation of iodide released after oxidation of cell components by I2.
authors.affiliation: Graduate School of Horticulture, Chiba University, 648 Matsudo, Matsudo City, Chiba, 271-8510, Japan.|Food Technology Department, Padjadjaran University, Jalan Raya Bandung Sumedang KM21, Bandung, 45363, Indonesia.
authors.forename: Tri
authors.initials: T
authors.lastname: Yuliana
authors.affiliation: Graduate School of Horticulture, Chiba University, 648 Matsudo, Matsudo City, Chiba, 271-8510, Japan.
authors.forename: Kyota
authors.initials: K
authors.lastname: Ebihara
authors.affiliation: Graduate School of Horticulture, Chiba University, 648 Matsudo, Matsudo City, Chiba, 271-8510, Japan.
authors.forename: Mio
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Graduate School of Horticulture, Chiba University, 648 Matsudo, Matsudo City, Chiba, 271-8510, Japan.
authors.forename: Chie
authors.initials: C
authors.lastname: Shimonaka
authors.affiliation: Graduate School of Horticulture, Chiba University, 648 Matsudo, Matsudo City, Chiba, 271-8510, Japan. amachi@faculty.chiba-u.jp.
authors.forename: Seigo
authors.initials: S
authors.lastname: Amachi
mesh_terms: D020561:Alphaproteobacteria / Q000201:enzymology / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000502:physiology; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000502:physiology; D007454:Iodides / Q000494:pharmacology*; D050296:Microbial Viability / Q000187:drug effects; D010088:Oxidoreductases / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D013171:Spores, Bacterial / Q000187:drug effects; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D007454:Iodides; D010088:Oxidoreductases
keywords: Antimicrobial system; Iodide; Multicopper oxidase; Povidone-iodine; Sporicidal activity