Abstract The aim of this study was to identify yeast strains and hop-tolerant lactic acid bacteria from Bozo, a traditional Kyrgyz-fermented beverage that has been described as a predecessor of today’s beer. The isolated cultures were screened for their potential use in beer fermentation. A functional beer beverage made from an ancestor of beer could prove innovative for craft brewing. The cultures were isolated using a selective medium (VLB-S7S-Agar, 10 International Bittering Units), as beer includes hop acids that are lethal to many lactic acid bacteria. The application of polymerase chain reaction (PCR) techniques (real-time PCR, PCR sequencing of a partial fragment of the 16S rDNA) revealed the lactic acid bacteria Lactobacillus plantarum, Lactobacillus casei, and Pediococcus parvulus as well as three different strains of the yeast species S. To produce a beer similar to the traditional Kyrgyz beverage Bozo, all-malt wort was fermented using pure cultures of the isolated microorganisms. One strain of S. cerevisiae showed traits of domestication in that it utilized maltotriose and did not produce phenolic off-flavors. The sensory properties of the produced beers were evaluated at the end of the fermentation. Changes were observed in parameters such as alcohol content and attenuation. The results show that the production of beer with Bozo-descendant yeast and bacteria strains can be an innovative way to create new products with similar positive physiological effects as described for Bozo in the Introduction.

中文翻译：

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筛选 Bozo 发酵剂以在啤酒发酵中的潜在应用

摘要 本研究的目的是从 Bozo 中鉴定酵母菌株和啤酒花耐受性乳酸菌，Bozo 是一种传统的吉尔吉斯发酵饮料，被描述为当今啤酒的前身。对分离的培养物进行筛选，以确定它们在啤酒发酵中的潜在用途。由啤酒祖先制成的功能性啤酒饮料可以证明对精酿啤酒具有创新意义。使用选择性培养基 (VLB-S7S-Agar, 10 International Bittering Units) 分离培养物，因为啤酒中含有对许多乳酸菌致命的啤酒花酸。应用聚合酶链反应 (PCR) 技术（实时 PCR、16S rDNA 部分片段的 PCR 测序）揭示了乳酸菌植物乳杆菌、干酪乳杆菌和小片球菌以及三种不同的酵母菌株种 S。为了生产类似于传统吉尔吉斯饮料 Bozo 的啤酒，使用分离微生物的纯培养物发酵全麦芽麦芽汁。一种酿酒酵母菌株显示出驯化特性，因为它利用麦芽三糖并且不产生酚类异味。在发酵结束时评估所生产啤酒的感官特性。观察到酒精含量和衰减等参数的变化。结果表明，用 Bozo 后代酵母和细菌菌株生产啤酒是一种创新方式，可以创造具有与前言中对 Bozo 描述的类似积极生理效应的新产品。酿酒酵母显示出驯化特征，因为它利用麦芽三糖并且不产生酚类异味。在发酵结束时评估所生产啤酒的感官特性。观察到酒精含量和衰减等参数的变化。结果表明，使用 Bozo 后代酵母和细菌菌株生产啤酒是一种创新方式，可以创造具有与 Bozo 在引言中描述的类似积极生理效应的新产品。酿酒酵母显示出驯化特征，因为它利用麦芽三糖并且不产生酚类异味。在发酵结束时评估所生产啤酒的感官特性。观察到酒精含量和衰减等参数的变化。结果表明，使用 Bozo 后代酵母和细菌菌株生产啤酒是一种创新方式，可以创造具有与 Bozo 在引言中描述的类似积极生理效应的新产品。