Open AccessExpression of β‐galactosidase in Rhizobium japonicum
Author(s) -
Johnson D.A.
Publication year - 1985
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.1574-6968.1985.tb01629.x
Subject(s) - lac operon , rhizobium , lactose , operon , escherichia coli , plasmid , strain (injury) , rhizobiaceae , biology , beta galactosidase , microbiology and biotechnology , glycine , bacteria , biochemistry , chemistry , gene , genetics , symbiosis , amino acid , anatomy
The plasmid pGC91.14 was used to introduce via conjugation the Escherichia coli lac operon into fast‐growing and slow‐growing strains of Rhizobium japonicum . Exconjugants now expressed higher levels of β‐galactosidase activity which was still inducible by isopropyl‐β‐ d ‐thiogalactoside (IPTG). The presence of the lac operon allowed the slow‐growing strain 61A76 to grow on lactose as the sole carbon source; the fast‐growing strains grew poorly on lactose but growth was not inhibited by lactose as had been reported for Rhizobium meliloti . β‐galactosidase could be detected in nodule extracts and bacteroid preparations from soybean plants ( Glycine max L. Merrill) infected with the strain 61A76 (pGC91.14).