MBAA TQ https://doi.org/10.1094/TQ-57-3-1015-01 | 
VIEW ARTICLE
Florian Priller and Elias Rietzschel. BIOTECON Diagnostics GmbH, Potsdam, Germany
Abstract
Beer is generally not susceptible to microbial contamination; however, severe spoilage can be caused by a variety of yeast, such as
Saccharomyces cerevisiae var.
diastaticus and Brettanomyces, leading to brand image damage. Detecting yeasts detrimental to beer or beer mixed drinks is therefore essential when ensuring the quality of the brewing process and finished products. In particular, trace amounts of viable cells cannot be detected directly in a beverage but need to proliferate above a certain threshold to be detected. In the current study, the growth characteristics of the most important types of spoilage yeast were comprehensively analyzed under selective and non-selective enrichment conditions. The optimal duration of pre-enrichment for sensitive detection by real-time PCR was found to be significantly variable, ranging between 1 and 5 days, depending on species and enrichment conditions. The sample type (e.g., different styles of beer) and the way the enrichment culture was prepared additionally influenced the growth behavior of spoilers. This can necessitate a prolongation of the enrichment by a further 1–3 days. The current study provides a valuable basis for breweries to determine minimum pre-enrichment times for the safe detection of beer-spoiling yeast.
