VIEW ARTICLE    DOI: 10.1094/ASBCJ-51-0158

Detection and Identification of Pectinatus cerevisiiphilus Using Surface-Reactive Monoclonal Antibodies in a Membrane Filter-Based Fluoroimmunoassay. Sheryl L. Gares and Michael S. Whiting, Department of Microbiology, W. M. Ingledew, Applied Microbiology and Food Science, and Barry Ziola, Department of Microbiology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 0W0. J. Am. Soc. Brew. Chem. 51:0158, 1993.

Pectinatus cerevisiiphilus causes spoilage of beer "in package" by producing end products with noxious off-flavors. Because this bacterium is strictly anaerobic, it is difficult to detect in beer. Isolation using selective media can take a week or longer, and more rapid direct or indirect detection methods have not been successfully applied. Believing that an immunoassay approach would facilitate detection and identification of contamination by P. cerevisiiphilus, we developed monoclonal antibodies (MAb) for use in such assays. Three of the five MAb described in this study react with surface antigens from P. cerevisiiphilus, whereas the other two react with the bacterial flagella. None of the MAb react with antigens from P. frisingensis or other brewing spoilage bacteria. A pool of the three bacterial surface-reactive MAb was used in a fluoroimmunoassay to detect P. cerevisiiphilus trapped on black membrane filters. As few as two to four bacteria were detectable in 10 ml of beer in less than 3 hr. This assay represents a substantial improvement in methodology for detection and identification of low levels of P. cerevisiiphilus.

Keywords: Bacterial contamination, Beer spoilage, Immunoassay, Monoclonal antibodies, Pectinatus cerevisiiphilus