Peter Trabold (1), Daniela Bocioaga (1), I. Cristina McGuire (1), Stephanie Morse (1), Amanda Ruby (1), Gwendolyn Spizz (1); (1) Rheonix Corporation, Grand Island, NY, U.S.A.
Finishing and Stability
Despite the inhospitable environment of beer toward the growth of microorganisms, craft brews remain susceptible to various spoilage organisms that have developed mechanisms that enable growth in the presence of hops, alcohol, and acidic conditions. The standard detection strategy for these spoilage organisms has traditionally involved culturing, a process that may take up to a week to obtain results. This wait is problematic for brewers and may result in delayed release or release of untested and potentially spoiled product to market. In contrast to culture, molecular detection provides a rapid, sensitive, and specific method of identifying the presence of beer spoilage organisms. Available kits on the market identify many species of spoilers, regardless of whether the specific strain contains genes associated with spoilage, or focus on a limited number of beer spoilage genes, risking lack of detection of other relevant spoilers. Most available tests require pre-enrichment and other lengthy preparative steps, in addition to sophisticated molecular lab equipment that may not be present in a craft brewery. This study describes the development of the Beer SpoilerAlert assay, a robust sample-to-results molecular detection system for beer spoilage organisms, including various species of lactic acid bacteria (LAB), and four genes associated with beer spoilage in LAB. Concurrently, the assay detects the presence of the wild yeast Brettanmoymces bruxellenis and brewer’s yeast. Samples taken at any point during the brewing process are loaded into sample tubes and placed in the sample rack. The sample rack, cartridges, and reagent kit are placed in the Encompass Optimum workstation and all processes required for lysing organisms, extracting nucleic acids, amplifying and detecting target genes, and analyzing results, are automatically performed without user intervention on the Rheonix CARD (Chemistry and Reagent Device) cartridges in the workstation. Reagents are dispensed by an onboard robot and liquid is moved via microfluidic pumps and channels within the cartridge. Amplification occurs via the onboard thermocycler and endpoint detection occurs through hybridization to a low-density capture array. Captured targets are detected and analyzed by an onboard camera and imaging software, which provides the user with a report of which genes and/or organisms are present. Four individual samples are analyzed per cartridge, with six cartridges per run, resulting in twenty-four independent samples analyzed in 5 hr, with minimal hands-on time. Due to the sensitivity of the assay, a pre-enrichment step is not required in most instances. However, if the user prefers to do so, a pre-enrichment step is compatible with this assay with no further modifications. The results described demonstrate validation of the assay using beer samples spiked with known microbes and actual beer samples suspected or known to contain spoilage organisms. Results were verified through conventional culturing methods.
Peter Trabold received a B.A. degree in biology and philosophy and an MBA and a Ph.D. in molecular and cellular biology from the University at Buffalo. He began working for ZeptoMetrix Corporation in 2005 and established the Bacteriology Department in 2007. As the manager of this department, he was responsible for the initial development of four distinct product lines for the research and clinical diagnostics infectious disease markets. In 2012, Peter was promoted to director of business development at ZeptoMetrix. Currently, Peter is the director of business development at Rheonix Corporation. In addition, Peter is currently president of the Western New York branch of ASM.