Laboratory of Microbiology and Biotechnology of Foods, Department of Food Science and Human Nutrition, School of Food and Nutritional Sciences, Agricultural University of Athens, Iera Odos 75, 11855, Greece.
Laboratory of Microbiology and Biotechnology of Foods, Department of Food Science and Human Nutrition, School of Food and Nutritional Sciences, Agricultural University of Athens, Iera Odos 75, 11855, Greece.
Int J Food Microbiol. 2021 Apr 16;344:109111. doi: 10.1016/j.ijfoodmicro.2021.109111. Epub 2021 Feb 23.
Currants are prone to contamination by ochratoxin during cultivation, processing and storage conditions. Saccharomyces cerevisiae is considered to be among the main species of grape yeast flora able to control antagonistic fungi. In this study, the potential of S. cerevisiae Y was investigated to inhibit the growth of several fungal species indigenous to the microbiota of grapes. Moreover, the efficacy of this yeast species was investigated to inhibit OTA by toxin producing fungi both in vitro and in situ. For this purpose thirty-five different fungal species, belonging to the genera Aspergillus, Penicillium, Cladosporium, Fusarium and Alternaria interacted in vitro with S. cerevisiae on Malt Extract agar plates, stored at 25 °C for 14 days. Results showed that the highest OTA producer A. carbonarius F was inhibited more than 99% from day 7, in contrast to A. niger strains that presented enhanced OTA production at day 14 due to interaction with S. cerevisiae Y. Additionally, the antifungal potential of the selected yeast was also studied in situ on currants subjected to different treatments and stored at 25 °C for 28 days. Microbiological analysis was undertaken for the enumeration of the bacterial and fungal flora, together with OTA determination at 7 and 21 days. To quantify A. carbonarius on all treated currant samples, molecular analysis with Real Time PCR was employed. A standard curve was prepared with A. carbonarius DNA. The efficiency of the curve was estimated to 10.416, the slope to -3.312 and the range of haploid genome that could be estimated was from 1.05 to 105∙10. The amount of A. carbonarius DNA in all treated currants samples, where the fungus was positively detected, ranged from as low as 0.08 to 562 ng DNA/g currants. The antifungal activity of S. cerevisiae Y was observed in all studied cases, causing inhibition of fungal growth and OTA production.
在种植、加工和储存过程中，醋栗容易受到赭曲霉毒素的污染。酿酒酵母被认为是能够控制拮抗真菌的主要葡萄酵母菌群之一。在这项研究中，研究了酿酒酵母 Y 抑制几种真菌的生长的潜力，这些真菌是葡萄微生物区系的固有真菌。此外，还研究了该酵母种在体外和体内抑制产毒真菌产生 OTA 的功效。为此，在麦芽提取物琼脂平板上，将属于曲霉属、青霉属、枝孢属、镰刀菌属和交链孢属的 35 种不同真菌与酿酒酵母 Y 相互作用，在 25°C 下储存 14 天。结果表明，OTA 产量最高的真菌 A. carbonarius F 在第 7 天就被抑制了 99%以上，而 A. niger 菌株由于与 S. cerevisiae Y 的相互作用，在第 14 天产生了更多的 OTA。此外，还研究了所选酵母的抗真菌潜力在不同处理的醋栗上的原位情况，并在 25°C 下储存 28 天。在第 7 天和第 21 天进行微生物分析，以计数细菌和真菌菌群，并测定 OTA。为了定量所有处理过的醋栗样本中的 A. carbonarius，采用实时 PCR 分子分析。用 A. carbonarius DNA 制备标准曲线。该曲线的效率估计为 10.416，斜率为-3.312，估计的单倍体基因组范围为 1.05 至 105∙10。在所有检测到真菌的处理过的醋栗样本中，A. carbonarius DNA 的量从低至 0.08 到 562 ng DNA/g 醋栗不等。在所有研究案例中都观察到了 S. cerevisiae Y 的抗真菌活性，导致真菌生长和 OTA 产生受到抑制。
