Detection of Pediococcus spp. in brewing yeast by a rapid immunoassay.
A membrane immunofluorescent-antibody test was developed to detect diacetyl-producing Pediococcus contaminants in brewery pitching yeast (yeast [Saccharomyces cerevisiae] slurry collected for reinoculation). Centrifugations at 11 and 5,100 x g separate yeast cells from bacteria and concentrate the bacteria, respectively. Pelleted bacteria resuspended and trapped on a black membrane filter are reacted with monoclonal antibodies specific for cell surface antigens and then with fluorescein-conjugated indicator antibodies. Whether pitching yeast is contaminated with pediococci at 0.001% is determined in less than 4 h. The sensitivity of the assay is 2 orders of magnitude below the Pediococcus detection limit of direct microscopy.
Whiting
M
M
Department of Microbiology, College of Medicine, University of Saskatchewan, Saskatoon, Canada.
Crichlow
M
M
Ingledew
W M
WM
Ziola
B
B
D005455:Fluorescent Antibody Technique; D010376:Pediococcus / Q000254:growth & development / Q000302:isolation & purification*; D012441:Saccharomyces cerevisiae / Q000254:growth & development* / Q000302:isolation & purification