Isolation and heavy metal resistance pattern of Frankia from Casuarina equisetifolia nodules

Six strains of Frankia were isolated from the root nodules of Casuarina equisetifolia using a newly standardized technique. The strains showed typical Frankia culture characteristics in liquid Q_mod as well as in nitrogen free defined propionate minimal medium (DPM). The vesicles were produced only in DPM medium. Visible nodule and typical root hair deformation was observed on Casuarina seedlings in reciprocal inoculation. Frankia strain CeSi1 was studied for sensitivity to nickel, copper, lead, cadmium and cobalt salts. It was found to be resistant to high concentration of cadmium and cobalt salts.