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Superoxide dismutase and catalase activities in purified Frankia vesicles
Author(s) -
Puppo Alain,
Dimitrijevic Lilliana,
Rigaud Jean
Publication year - 1989
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1989.tb05646.x
Subject(s) - frankia , superoxide dismutase , catalase , vesicle , biochemistry , biology , hypha , enzyme , chemistry , nitrogen fixation , microbiology and biotechnology , root nodule , bacteria , genetics , membrane
Superoxide dismutase (EC 1.15.1.1.) and catalase (EC 1.11.1.6.) activities of Frankia cells grown in the presence of ammonium were very high in comparison with those of other prokaryaotes and particularly Rhizobium . Furthermore, these activities were significantly enhanced under nitrogen‐fixing conditions where vesicles were produced. By using a single‐step sucrose gradient, Frankia vesicles were isolated and appeared intact and free of hyphal contamination. The contents of superoxide dismutase and catalase in the purified vesicles were similar to those in preparations containing both vesicles and hyphae. These results suggest an important role of superoxide dismutase and catalase in the protection of the overall nitrogen‐fixation process against O 2 in Frankia vesicles. Beside the protective role played by the thick walls of the vesicles, the presence of specialized enzymes is emphasized.