Abstract Beer is a hostile environment for microorganisms to survive. However, some strains of lactic acid bacteria (LAB) have chosen this harsh environment for their ecological niche and evolved by incrementally acquiring various genetic elements to overcome a range of growth hurdles posed by beer. In fact, over 100 genes appear to be involved for one beer spoilage LAB strain to grow in and spoil beer. Although many of them are chromosomally encoded genes, an increasing number of brewery-specific genetic clusters have been also identified on plasmids, which are often horizontally shared by a variety of beer spoilage LAB species/strains. These plasmid-localized genetic factors were once represented by hop tolerance genes, such as horA, horC, and hitA, that were uncovered in the early days of hop tolerance research. But the recent evidence increasingly indicates that beer spoilage potential of LAB is conferred by multifactorial and complex adaptive responses that are related to a large number of defense mechanisms, including divalent cation homeostasis, cell envelope modification, oxidative stress response, and pH homeostasis. Many of these defense systems have been shown to be encoded on plasmids that are carried by beer spoilage LAB. In the past decade, new plasmid-encoded diagnostic marker genes (DMGs), such as gtfD15 and fabZ, have been additionally reported for the discrimination of beer spoilage potential of LAB strains. This review summarizes the recent progress in this area of research and provides some insights into the microbiological quality control (QC) tests adopted in brewery laboratories.

中文翻译：

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质粒在啤酒腐败乳酸菌中的作用：综述

摘要 啤酒是微生物赖以生存的恶劣环境。然而，一些乳酸菌 (LAB) 菌株选择了这种恶劣的环境作为其生态位，并通过逐步获取各种遗传元素来克服啤酒带来的一系列生长障碍。事实上，似乎有 100 多个基因与一种啤酒腐败 LAB 菌株的生长和啤酒腐败有关。尽管其中许多是染色体编码的基因，但在质粒上也发现了越来越多的啤酒厂特异性基因簇，这些基因簇通常由各种啤酒腐败 LAB 物种/菌株水平共享。这些质粒定位的遗传因子曾经以耐啤酒花基因为代表，如 horA、horC 和 hitA，这些基因在啤酒花耐受性研究的早期就被发现了。但最近越来越多的证据表明，LAB 的啤酒腐败潜力是由多因素和复杂的适应性反应赋予的，这些反应与大量防御机制有关，包括二价阳离子稳态、细胞包膜修饰、氧化应激反应和 pH 稳态。许多这些防御系统已被证明是由啤酒腐败 LAB 携带的质粒编码的。在过去的十年中，新的质粒编码诊断标记基因 (DMG)，例如 gtfD15 和 fabZ，已被另外报道用于区分 LAB 菌株的啤酒腐败潜力。本综述总结了该研究领域的最新进展，并对啤酒厂实验室采用的微生物质量控制 (QC) 测试提供了一些见解。