Methods for detection and identification of beer-spoilage microbes

Abstract

It is critical that breweries of all sizes routinely monitor the microbiome of their process to limit financial losses due to microbial contamination. Contamination by beer-spoiling microbes (BSMs) at any point during the brewing process may lead to significant losses for breweries if gone undetected and allowed to spread. Testing and detection of BSMs must be routine and rapid, and because even small breweries need the capability of BSM detection and identification, the method also needs to be affordable. Lactic acid bacteria (LAB) are responsible for most spoilage incidents, many of which have been shown to enter the viable but nonculturable (VBNC) state under conditions present in beer such as cold or oxidative stress. These bacteria are invisible to traditional methods of detection using selective media. This article describes several methods of BSM detection and identification that may be useful in the majority of craft breweries. While there are several genomic methods that meet some or many qualifications of being useful in craft breweries, real-time quantitative polymerase chain reaction (qPCR) currently best meets the desired method characteristics and holds the most utility in this industry, specifically SYBR Green qPCR. qPCR is a targeted method of detection and identification of microbes that is affordable, rapid, specific, sensitive, quantitative, and reliable, and when paired with valid DNA extraction techniques can be used to detect BSMs, including those in the VBNC state.

Autochthonous Ingredients for Craft Beer Production

“…In this study, the main difference between recipes A and B and recipes C and D is the hops used for the aroma. Contrary to previous observations by other authors [64], the highest population differences between the plating and qPCR analyses were observed for recipes C and D, which presented the lowest αacids content (Table 3). In this case, they cannot be directly related to the differences in cell enumeration.…”

“…Most investigations using the qPCR application in beer had been directed at the detection of spoilage microorganisms during beer elaboration [62][63][64]. In the current work, this qPCR technique was used to monitor inoculated S. cerevisiae strains in beer fermentation in comparison with a culture-dependent method.…”

Characterize Type of Splicing Languages via Directed Splicing Graph

“…Thus, with comparison made to Yusof [14], 𝑠 1 and 𝑠 2 are transient language but not active persistent language. Meanwhile, 𝑠 3 and 𝑠 4 which are the inert persistent language, can be classified as adult language as there is no restriction enzyme exist from the New England Biolabs (NEB) catalogue [21], to further cut the strings.…”

Depiction of the In Vitro and Genomic Basis of Resistance to Hop and High Hydrostatic Pressure of Lactiplantibacillus plantarum Isolated from Spoiled Beer

“…Some microorganisms tolerate beer parameters and lead to changes in beers, like turbidity, sedimentation, acidity, sometimes with a diacetyl flavor [ 1 , 2 ], and unpleasant odor caused by compounds such as butyric acid, caproic acid, and hydrogen sulfide [ 13 ]. In a recent review, the methods for detecting and identifying beer-spoiling microorganisms were summarized by Oldham and Held, 2023 [ 14 ]. Beer spoilage microorganisms range from Gram-positive and Gram-negative bacteria to fungi, including wild yeasts and molds.…”