Cellulase isoenzyme profiles in Frankia strains belonging to different cross-inoculation groups

Carboxymethyl cellulase activities were evaluated in eight strains of Frank ia from diverse host specificity groups and geographical origins. Cellulase activity was detected in culture supernatants of all strains in the absenc e of CMC (Carboxymethylcellulose) as an inducer using both double-layer pla te and reducing sugar assays, indicating a constitutive production of CM-ce llulases by Frankia. CM-cellulase isoenzyme profiles were visualized using activity gel electrophoresis of concentrated culture supernatants. Differen t electrophoretic profiles were observed among the eight strains tested, wh ich correlate with the host specificity and taxonomic grouping of Frankia.