Potential of Two Metschnikowia pulcherrima (Yeast) Strains for In Vitro Biodegradation of Patulin

Agroinnova, Centre of Competence for the Innovation in the Agro-Environmental Sector, Universita degli Studi di Torino, via L. da Vinci 44, 10095 Grugliasco, Torino, Italy.
Journal of food protection (Impact Factor: 1.85). 01/2011; 74(1):154-6. DOI: 10.4315/0362-028X.JFP-10-331
Source: PubMed


Patulin contamination of apple and other fruit-based foods and beverages is an important food safety issue, as consumption of these commodities throughout the world is great. Studies are therefore necessary to reduce patulin levels to acceptable limits or undetectable levels to minimize toxicity. This study was undertaken to investigate the efficacy of two Metschnikowia pulcherrima strains (MACH1 and GS9) on biodegradation of patulin under in vitro conditions. These yeast strains were tested for their abilities to degrade patulin in liquid medium amended with 5, 7.5, 10, and 15 μg/ml patulin and a yeast cell concentration of 1 × 10(8) cells per ml at 25°C. Of the two strains tested, MACH1 completely (100%) reduced patulin levels within 48 h, and GS9 within 72 h, at all concentrations of patulin. MACH1 effectively degraded the patulin within 24 h by 83 to 87.4%, and GS9 by 73 to 75.6% at 48 h, regardless of concentration. Patulin was not detected in yeast cell walls. This indicates that yeast cell walls did not absorb patulin, and that they completely degraded the toxin. Patulin had no influence on yeast cell concentration during growth. Therefore, these yeast strains could potentially be used for the reduction of patulin in naturally contaminated fruit juices. To our knowledge, this is the first report regarding the potential of M. pulcherrima strains for patulin biodegradation.

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    • "Some components of the microbial community present on the surface of fruit and vegetables, such as bacteria and yeasts, have been shown to have significant antagonistic activity against P. expansum (Usall et al., 2001; Janisiewicz and Korsten, 2002). Different yeasts are also able to reduce the patulin level in vitro (Coelho et al., 2008; Reddy et al., 2011). Fermentative yeasts reduce patulin contamination during production of cider from apple juice (Harwig et al., 1973). "
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