Those bacterial endophytes that also provide some benefit to plants may be considered to be plant growthpromoting
bacteria (PGPB) and can facilitate plant growth by a number of different mechanisms. In the
work that is reported here, soil samples from several locales around the world were used as a starting
point for the isolation of new endophytes. Subsequently, those newly isolated endophytes that were able
to utilize the plant compound 1-aminocyclopropane-1-carboxylate (ACC) as a sole source of nitrogen,
as a consequence of possessing the enzyme ACC deaminase, were selected for additional characterization.
More specifically, ACC deaminase-expressing strains were tested for IAA synthesis, siderophore
production, phosphate solubilization activity, optimal growth temperature, salt tolerance, and antibiotic
sensitivity. In addition, the partial DNA sequences of the16S rRNA genes of the characterized strains were
determined so that the taxonomic identity of each strain could be assessed, and the ability of some of
these strains to facilitate the growth of canola plant roots under controlled gnotobiotic conditions was
measured.