AN ENZYME-LINKED-IMMUNOSORBENT-ASSAY (ELISA) FOR DETECTION OF CLOSTRIDIUM-ALDRICHII IN ANAEROBIODIGESTERS

Monoclonal antibodies (Mabs) against Clostridium aldrichii were prepar ed by in vivo and in vitro immunization with whole cells and produced after fusion as ascites in BALB/c mice, An enzyme-linked immunosorbent assay (ELISA) was used to test for specificity and sensitivity of the Mabs to detect CI. aldrichii. The lower limit for Cl. aldrichii detec tion in pure and mixed culture with ELISA was 10(5) cells ml(-1). Twen ty other species of bacteria, including 12 celluloytic species, were t ested for cross-reactivity with the ELISA, but none was detected. The ELISA was used for detection of Cl. aldrichii over a 16-month period i n five mesophilic continuously-stirred tank reactors (CSTR) with wood, glucose, sludge or sorghum as substrates. The population of Cl. aldri chii in the poplar wood anaerobic digester effluent was 10(6)-10(7) ce lls ml(-1) over that time. These numbers were confirmed by anaerobic m icrobiological methods. Results from the ELISA technique were obtained in 36 h vs 3 weeks for culture methods. It is concluded that the ELIS A is a useful, time-saving method for identification, detection and qu antification of Cl. aldrichii in axenic, mixed culture, and in complex undefined cultures such as those found in anaerobic digesters.