Abstract Microbial spoilage of alcohol-free and low-alcohol beers, beer-mixed beverages, and soft drinks is most commonly caused by yeast. Yeast-related biofilms are therefore a serious problem in the production of these beverages. Fast detection of developing biofilms is a key factor to prevent subsequent spoilage of the product. For fast yeast detection, a new specific medium was developed and combined with real-time polymerase chain reaction (PCR) detection of characteristic beverage spoiling yeast species. The medium is based on MYPG broth (malt extract, yeast extract, peptone, glucose broth) with resazurin as a redox indicator for cell activity. The growth and biofilm potential of representative strains of commonly present beverage spoilage yeast species was evaluated using the developed medium. A novel real-time PCR detection system for Rhodotorula mucilaginosa, an early biofilm colonizer, was designed and successfully validated. Two field tests of the medium in combination with real-time PCR were performed. One test showed a differentiated hygienic status on a filler, and the other test tracked the contamination source of Saccharomyces cerevisiae var. diastaticus. Biofilm relevance of the strain set was proven. The modified MYPG proved to be highly sensitive when detecting yeasts. The detection of the selected target species directly in the medium was compatible and can provide detailed hygienic profiles when combined with additional information on the target species. This provides a fast detection method for yeast-related biofilms in brewery environments, differentiated hygienic monitoring, and makes it possible to troubleshoot contamination incidents.

中文翻译：

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联合酵母生物膜筛选——在酿造环境中表征和验证酵母相关生物膜，结合培养和特定实时 PCR 筛选选定的指示物种

摘要 无酒精和低度酒精啤酒、啤酒混合饮料和软饮料的微生物腐败最常由酵母引起。因此，酵母相关生物膜是这些饮料生产中的一个严重问题。快速检测正在形成的生物膜是防止产品随后变质的关键因素。对于快速酵母检测，开发了一种新的特定培养基，并结合了对特征饮料变质酵母种类的实时聚合酶链反应 (PCR) 检测。该培养基基于 MYPG 肉汤（麦芽提取物、酵母提取物、蛋白胨、葡萄糖肉汤），刃天青作为细胞活性的氧化还原指示剂。使用开发的培养基评估了常见饮料腐败酵母种类的代表性菌株的生长和生物膜潜力。设计并成功验证了一种新的实时 PCR 检测系统，用于早期生物膜定植菌粘液红酵母。结合实时 PCR 对培养基进行了两次现场测试。一项测试显示了填料的不同卫生状态，而另一项测试则追踪了酿酒酵母变种的污染源。糖皮质激素。已证明菌株组的生物膜相关性。在检测酵母菌时，改进的 MYPG 被证明是高度敏感的。直接在培养基中检测选定的目标物种是兼容的，当与目标物种的其他信息结合时，可以提供详细的卫生概况。这为啤酒厂环境中酵母相关生物膜的快速检测、差异化卫生监测、