Lactoperoxidase is a member of the family of the mammalian heme peroxidases which have a broad spectrum of activity. Their best known effect is their antimicrobial activity that arouses much interest in in vivo and in vitro applications. In this context, the proper use of lactoperoxidase needs a good understanding of its mode of action, of the factors that favor or limit its activity, and of the features and properties of the active molecules. The first part of this review describes briefly the classification of mammalian peroxidases and their role in the human immune system and in host cell damage. The second part summarizes present knowledge on the mode of action of lactoperoxidase, with special focus on the characteristics to be taken into account for in vitro or in vivo antimicrobial use. The last part looks upon the characteristics of the active molecule produced by lactoperoxidase in the presence of thiocyanate and/or iodide with implication(s) on its antimicrobial activity.

This study documented the reliability of oral swabbing when investigating yeast carriage in healthy denture wearers. Moreover, just a diagnostic tool, sampling upper dentures for Candida could be the opportunity to verify the patient's compliance to hygiene advice.

Controlling pests in pre-and postharvest crops using natural and lowimpact products is a major challenge. The lactoperoxidase system is an enzymatic system that exists in all external secretions in mammals and is part of the non-immune system. We tested its efficacy in in vitro microplates on Phytophthora infestans, Penicillium digitatum, Penicillium italicum, Penicillium expansum and Botrytis cinerea to determine the most suitable concentrations for use. Then, we verified its efficacy in planta under controlled conditions. Solutions prepared with 5.4 mM iodide and 1.2 mM thiocyanate and diluted threefold inhibited pathogen growth in vitro by 63-100%. Twofold-diluted solutions protected potato plants against P. infestans by 60-74% under controlled conditions. Undiluted solution inhibited orange's and apple's postharvest pathogens in curative application with efficacy levels ranging between 84 and 95% in orange and between 63 and 74% in apple. 1.5-fold concentrated solutions inhibited postharvest pathogens of apple in curative application with efficacy levels ranging between 84 and 92%. Our results also show that the oxidative stress response of fruit following wounding could interfere with ion efficiency. Our tests demonstrate for the first time that this biochemical method is as efficient as a conventional synthetic chemical method under controlled conditions. 2011). Then, sexual reproduction spread across northern Europe, leading to higher genetic diversity (Cooke et al. 2011;Yuen and Andersson 2013;Wiik 2014). This also increased the capacity of the pathogen to J Phytopathol 165 (2017) 22-34 Ó 2016 Blackwell Verlag GmbH 22 J Phytopathol Penicillium expansum, Penicillium digitatum, Penicillium italicum and Botrytis cinerea cultures Penicillium expansum (CBS 484.75), P. digitatum (MUCL 39704), P. italicum ( MUCL 15608) and B. cinerea strain V (isolated from decayed fruit in our laboratory) were grown on potato dextrose agar at 25°C in a culture chamber. After 10 days (for the Penicillium strains) and 3 weeks (for B. cinerea) of incubation, conidia were collected by adding 9 ml of sterile 0.05% Tween water on the plate. Conidia were scraped off with a sterile inoculating loop and filtered through a sterilized double-layer fine cloth. The

The potential of ions produced in water by the lactoperoxidase system against plant pests has shown promising results. We tested the bioactivity of ions produced by the lactoperoxidase oxidation of I and SCN in several buffers or in tap water and characterized the ions produced. In vitro biological activity was tested against Penicillium expansum, the causal agent of mold in fruits, and the major cause of patulin contamination of fruit juices and compotes. In buffers, the ionic concentration was increased 3-fold, and pathogen inhibition was obtained down to the 1:15 dilution. In tap water, the ionic concentration was weaker, and pathogen inhibition was obtained only down to the 1:3 dilution. Acidic buffer increased ion concentrations as compared to less acidic (pH 5.6 or 6.2) or neutral buffers, as do increased ionic strength. C-labelled SCN and MS showed that different ions were produced in water and in buffers. In specific conditions the ion solution turned yellow and a product was formed, probably diiodothiocyanate (I SCN ), giving an intense signal at 49.7 ppm in C-NMR. The formation of the signal was unambiguously favored in acidic media and disadvantaged or inhibited in neutral or basic conditions. It was enhanced at a specific SCN : I ratio of 1:4.5, but decreased when the ratio was 1:2, and was inhibited at ratio SCN >I . We demonstrated that the formation of the signal required the interaction between I and SCN , and MS showed the presence of I SCN .

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