Brewing spoilage lactobacilli detected using monoclonal antibodies to bacterial surface antigens

A panel of thirteen monoclonal antibodies (Mabs) was assembled that reacts with surface antigens on eight of eleven Lactobacillus brewing spoilage organisms, including one or more of L. brevis, L. buchneri, L. caseialactosus, L. planatarum, or unspeciated isolate(s). Immunoblotting was done to identify the antigens involved in Mab binding. Antigen stability in situ was tested by protease treatment and by surface antigen extraction of washed bacteria. Protease susceptibility of extracted surface antigens was also examined. In most cases, Lactobacillus surface antigens detected by the Mabs appear to be noncovalently bound proteins readily altered or removed from the bacterium by various environmental conditions. This research identifies brewing conditions that need to be tested to ascertain whether bacterial surface antigen-reactive Mabs can be used for the rapid, sensitive, and specific detection of Lactobacillus brewing spoilage organisms.