Bocioaga, D.1, Kozak, S.1, Mix, K.1, Morse, S.1, Sorensen, K.1, McGuire, C.1, Trabold, P.1, MacLeod, A.2 and Spizz, G.1, (1)Rheonix, Inc., Ithaca, NY, USA, (2)Hartwick College Center for Craft Food and Beverage, Oneonta, NY, USA
Poster
Despite the hostile environment beer presents to the growth of most bacteria, strains of lactic acid bacteria (LAB) have evolved mechanisms allowing survival and growth in beer that ultimately may lead to spoiled product. Identification of spoilage organisms in beer has typically been done using culture-based detection methods, taking as much as a week to obtain results. Furthermore, the current methods test only for the presence of the bacteria, but do not identify whether the detected strain would actually propagate in the beer in which it was found. This is relevant in the rapidly growing brewing industry distinguished by the development of beers that differ significantly in levels of international bitterness units (IBUs) determined by the concentration and types of hops used in the recipe. In contrast, nucleic acid-based detection methods enable more rapid determination of the presence of potential spoiler organisms. Similarly, if the appropriate sequences are analyzed, these methods also distinguish not only the presence of the organism, but whether it has the capability of growing in the presence of iso-alpha-acids derived from hops. The purpose of this study was to evaluate sensitivity, specificity, and adaptability of the Rheonix Beer SpoilerAlert™ assay, a fully automated sample-to-results multiplexing molecular detection kit. The assay targets four distinct sequences enabling rapid detection of potential spoilage LAB and four sequences informing the presence of hop-resistant genes. Furthermore, spoilage concerns for brewers are not limited to bacteria, but also extend to the presence of yeast. Therefore, the assay also targets three yeast sequences demonstrating the presence of Saccharomyces cerevisiae (brewer’s yeast), S. cerevisiae var. diastaticus and Brettanomyces bruxellensis. The presence of S. cerevisiae var. diastaticus is of particular concern due to its significantly close similarity to brewer’s yeast and, thus, could remain easily undetectable until it spoils beer in the marketplace. B. bruxellensis provides another problem in that it is sometimes used to make specific beers, and thus, the risk increases of cross-contamination in the same brewery between a B. bruxellensis containing and non-containing beer. Results of the study demonstrated sensitivity for all target organisms of approximately 104 cfu/mL and less than 10 cfu/sample before enrichment. Data will also be shown regarding the adaptability of the system for use with all types of matrices expected from the brewery, including, but not limited to, in-process samples, final product, individual colonies, and environmental samples. The specificity of the assay for the targets via exclusivity analysis will be presented. This rapid method for the multiplexed detection of 11 gene sequences from a single sample reduces processing time compared to culture and provides a genetic characterization of the bacterial genes that confer hop resistance. This provides brewers with better information regarding the presence of spoilage microorganisms in their products and brewery environment and allows them to make more rapid and informed decisions regarding safe delivery of product.
Peter Trabold received a B.A. degree in biology and philosophy, an MBA, and a Ph.D. degree in molecular and cellular biology from the University at Buffalo. He began working for ZeptoMetrix Corporation developing non-infectious molecular controls for the infectious disease marketplace. Currently, Peter is the director of business development at Rheonix, Inc., helping to develop fully automated, multiplexed, molecular assays for food, beverage, and clinical markets. In addition, Peter is a former president of the Western New York branch of the American Society for Microbiology.
View Presentation
