3 results on '"Maria Grazia Farbo"'
Search Results
2. Effect of yeast volatile organic compounds on ochratoxin A-producing Aspergillus carbonarius and A. ochraceus
- Author
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Pietro Paolo Urgeghe, Stefania Oggiano, Zahoor Ul Hassan, Quirico Migheli, Maria Grazia Farbo, Angela Marcello, Samir Jaoua, Virgilio Balmas, and Stefano Fiori
- Subjects
0301 basic medicine ,Ochratoxin A ,Post-harvest ,030106 microbiology ,Microbiology ,Food safety ,Mixed Function Oxygenases ,03 medical and health sciences ,chemistry.chemical_compound ,Polyketide synthase ,Gene Expression Regulation, Fungal ,Humans ,Vitis ,Food science ,Peptide Synthases ,Mycotoxin ,Volatile Organic Compounds ,biology ,Antifungal compounds ,Chemistry ,food and beverages ,General Medicine ,Contamination ,Mycotoxins ,Phenylethyl Alcohol ,Spores, Fungal ,biology.organism_classification ,Ochratoxins ,Yeast ,Spore ,030104 developmental biology ,Aspergillus ,Biological Control Agents ,Biological control ,Fruit ,biology.protein ,2-Phenylethanol ,Microbial Interactions ,Fermentation ,Gene expression ,Aspergillus ochraceus ,Polyketide Synthases ,Food Science - Abstract
Many foods and beverages in temperate and tropical regions are prone to contamination by ochratoxin A (OTA), one of the most harmful mycotoxins for human and animal health. Aspergillus ochraceus and Aspergillus carbonarius are considered among the main responsible for OTA contamination. We have previously demonstrated that four low or non- fermenting yeasts are able to control the growth and sporulation of OTA-producing Aspergilli both in vitro and on detached grape berries: the biocontrol effect was partly due to the release of volatile organic compounds (VOCs). Aiming to further characterise the effect of VOCs produced by biocontrol yeast strains, we observed that, beside vegetative growth and sporulation, the volatile compounds significantly reduced the production of OTA by two A. carbonarius and A. ochraceus isolates. Exposure to yeast VOCs also affected gene expression in both species, as confirmed by downregulation of polyketide synthase, non-ribosomal peptide synthase, monooxygenase, and the regulatory genes laeA and veA. The main compound of yeast VOCs was 2-phenylethanol, as detected by Headspace-Solid Phase Microextraction-Gas Chromatography-Tandem Mass Spectrometry (HS-SPME-GC?MS) analysis. Yeast VOCs represent a promising tool for the containment of growth and development of mycotoxigenic fungi, and a valuable aid to guarantee food safety and quality. This publication was made possible by NPRP grant # 8-392-4-003 from the Qatar National Research Fund (a member of Qatar Foundation). The findings achieved herein are solely the responsibility of the authors. We acknowledge constructive comments provided by anonymous reviewers. Scopus
- Published
- 2017
3. Adsorption of ochratoxin A from grape juice by yeast cells immobilised in calcium alginate beads
- Author
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Samir Jaoua, Quirico Migheli, Maria Grazia Farbo, Salvatore Marceddu, Stefano Fiori, and Pietro Paolo Urgeghe
- Subjects
0106 biological sciences ,0301 basic medicine ,Ochratoxin A ,Mycotoxin contaminants ,Calcium alginate ,Alginates ,Beverage industry ,Food Contamination ,Aspergillus carbonarius ,01 natural sciences ,Microbiology ,Food safety ,Beverages ,03 medical and health sciences ,chemistry.chemical_compound ,Bioreactors ,Glucuronic Acid ,010608 biotechnology ,Bioreactor ,Vitis ,Magnetite Nanoparticles ,Mycotoxin ,Bioreactor systems ,Decontamination ,Candida ,Chromatography ,Hexuronic Acids ,Biological decontamination ,Biosorption ,food and beverages ,General Medicine ,Human decontamination ,Mycotoxins ,Ochratoxins ,Yeast ,Candida intermedia ,030104 developmental biology ,chemistry ,Food Microbiology ,Adsorption ,Cell immobilisation ,Food Science - Abstract
Grape juice can be easily contaminated with ochratoxin A (OTA), one of the known mycotoxins with the greatest public health significance. Among the different approaches to decontaminate juice from this mycotoxin, microbiological methods proved efficient, inexpensive and safe, particularly the use of yeast or yeast products. To ascertain whether immobilisation of the yeast biomass would lead to successful decontamination, alginate beads encapsulating Candida intermedia yeast cells were used in our experiments to evaluate their OTA-biosorption efficacy. Magnetic calcium alginate beads were also prepared by adding magnetite in the formulation to allow fast removal from the aqueous solution with a magnet. Calcium alginate beads were added to commercial grape juice spiked with 20μg/kg OTA and after 48h of incubation a significant reduction (>80%), of the total OTA content was achieved, while in the subsequent phases (72–120h) OTA was slowly released into the grape juice by alginate beads. Biosorption properties of alginate-yeast beads were tested in a prototype bioreactor consisting in a glass chromatography column packed with beads, where juice amended with OTA was slowly flowed downstream. The adoption of an interconnected scaled-up bioreactor as an efficient and safe tool to remove traces of OTA from liquid matrices is discussed. This publication was made possible by NPRP grants # NPRP 4-259-2-083 and # NPRP 8-392-4- 003 from the Qatar National Research Fund (a member of Qatar Foundation).
- Published
- 2015
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