VTT Technical Research Centre of Finland, Espoo, Finland.
Yeast. 2022 Jan;39(1-2):141-155. doi: 10.1002/yea.3687. Epub 2022 Jan 12.
Breweries produce an increasing selection of beer and nonbeer beverages. Yeast and filamentous fungi may compromise quality and safety of these products in several ways. Recent studies on fungal communities in breweries are scarce and mostly conducted with culture-dependent methods. We explored fungal diversity in the production of alcoholic and nonalcoholic beverages in four breweries. Samples were taken for next generation sequencing (NGS) at the key contamination sites in 10 filling lines. Moreover, fungal isolates were identified in 68 quality control samples taken from raw materials, filling line surfaces, air, and products. NGS gave a comprehensive view of fungal diversity on filling line surfaces. The surface-attached communities mainly contained ascomycetous fungi. Depending on the site, the dominant genera included Candida, Saccharomyces, Torulaspora, Zygosaccharomyces, Alternaria, Didymella, and Exophiala. Sanger sequencing revealed 28 and 27 species of yeast and filamentous fungi, respectively, among 91 isolates. The most common species Saccharomyces cerevisiae, Zygosaccharomyces rouxii, and Wickerhamomuces anomalus were detected throughout production. Filling line surface and air samples showed the greatest diversity of yeast and filamentous fungi, respectively. The isolates of the most common yeast genera Candida, Pichia, Saccharomyces, and Wickerhamomyces showed low spoilage abilities in carbonated, chemically preserved drinks but could grow in products with reduced hurdles. Preservative resistant yeasts were rare, belonging to the species Dekkera bruxellensis, Pichia manschurica, and Zygosaccharomyces bailii. Penicillium spp. were dominant filamentous fungi. The results of this study help to evaluate spoilage risks caused by fungal contaminants detected in breweries.
啤酒厂生产越来越多的啤酒和非啤酒饮料。酵母和丝状真菌可能会以多种方式影响这些产品的质量和安全性。最近关于啤酒厂中真菌群落的研究很少，并且大多使用基于培养的方法进行。我们在四个啤酒厂的酒精和非酒精饮料生产中探索了真菌多样性。在 10 条灌装线的关键污染点采集样本进行下一代测序（NGS）。此外，从原材料、灌装线表面、空气和产品中采集了 68 份质量控制样本，鉴定真菌分离物。NGS 全面展示了灌装线表面的真菌多样性。表面附着的群落主要含有子囊菌。根据地点的不同，优势属包括假丝酵母属、酿酒酵母属、葡萄孢酵母属、德克酵母属、交链孢属、漆斑菌属和外瓶霉属。Sanger 测序在 91 个分离物中分别鉴定出 28 种和 27 种酵母和丝状真菌。在整个生产过程中，最常见的物种包括酿酒酵母、鲁氏德克酵母和异常威克汉姆酵母。灌装线表面和空气样本分别显示出酵母和丝状真菌的最大多样性。最常见的酵母属假丝酵母属、毕赤酵母属、酿酒酵母属和威克汉姆酵母属的分离物在碳酸、化学保存饮料中表现出较低的腐败能力，但可以在减少障碍的产品中生长。抗防腐剂酵母很少，属于德克酵母、曼氏假丝酵母和毕赤酵母。青霉属是优势丝状真菌。本研究的结果有助于评估啤酒厂检测到的真菌污染物引起的腐败风险。
