Open AccessFree‐living and symbiotic nitrogen fixing ability of Rhizobium japonicum is unaffected by rifampicin resistance mutations
Author(s) -
Regensburger Brigitte,
Hennecke Hauke
Publication year - 1984
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1984.tb00189.x
Subject(s) - mutant , biology , rhizobium , nitrogen fixation , rifampicin , enzyme , rhizobiaceae , rna polymerase , microbiology and biotechnology , symbiosis , polymerase , biochemistry , rna , genetics , gene , bacteria , antibiotics
The hypothesis that rifampicin resistance mutations (possibly leading to altered RNA polymerases) have a pleiotropic effect on symbiotic nitrogen fixation was tested using the Rhizobium japonicum ‐soybean symbiosis. A total of 20 spontaneous rifampicin‐resistant mutants of R. japonicum strain 110 were analyzed biochemically. RNA polymerase assays revealed that the enzyme from 15 mutants was indeed rifampicin‐insensitive. Two of these mutants were found to possess an enzyme with an electrophoretically altered β subunit. All rifampicin‐resistant mutants were able to form nodules on soybeans and fix nitrogen symbiotically; free‐living nitrogen fixation under microaerophilic culture conditions was also unaffected.