“The iron requirements of the opportunistic pathogenic yea

“The iron requirements of the opportunistic pathogenic yeast, Candida albicans, and the related

nonpathogenic spoilage yeast Candida vini were investigated along with their responses to various exogenous iron chelators. The influence of iron as well as the exogenous chelating agents lactoferrin, EDTA, deferiprone, desferrioxamine, bathophenanthroline sulphonate and a novel carried chelator with a hydroxypyridinone-like Fe-ligand functionality, DIBI, on fungal growth was studied in a chemically defined medium deferrated to trace iron levels (<1.2 μg L−1 or 0.02 μM of Fe). Candida albicans competed better at low iron levels compared with C. vini, which was also more susceptible to most added chelators. Candida albicans was resistant to lactoferrin at physiologically relevant concentrations, but was inhibited by low find more concentrations of DIBI. Candida vini was sensitive to lactoferrin as well as to DIBI, whose inhibitory activity was shown to be Fe reversible. The pathogenic potential of C. albicans and the nonpathogenic nature of C. vini were consistent with their differing abilities to grow under iron-limiting conditions

and in the presence of exogenous iron chelators. Both yeasts could be controlled by appropriately strong chelators. This work provides the first evidence of the iron requirements of the spoilage organism C. vini and its response to exogenous chelators. Efficient iron withdrawal has the potential to provide the learn more basis for ROCK inhibitor new fungal growth control strategies. Microbial spoilage of foods, beverages and other aqueous consumer products, such as personal care cosmetics or ophthalmic solutions, presents significant challenges for product preservation and may lead to health implications. Traditional techniques involving chemical preservatives to suppress microorganisms can have the limitation of the development of microbial resistances (Russell, 1991; Chapman, 2003) and may not generally be compatible with product formulations

or may lead to undesirable reactions among sensitive consumers (Jong et al., 2007). Fungal spoilage is particularly important, given their propensity for growth at low pH values, as often used to inhibit bacterial growth. Combinations of chemical agents within a so-called hurdle approach to preservation have yielded some improvements (Leistner, 2000). For example, EDTA, which is known to chelate Fe, Ca and various other essential cations (Ueno et al., 1992), has been shown to increase the sensitivities of preservative-tolerant isolates, such as Pseudomonas (Chapman et al., 1998). The underlying iron requirement of microbial growth could provide the basis for a general approach to increasing microbial stability of products.

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