GENOME ANALYSIS OF 5 SOIL BACTERIAL ISOLATES NAMED FORMERLY ENTEROBACTER-AGGLOMERANS

The genomes of five nitrogen-fixing strains isolated from the vicinity of Bayreuth and named formerly Enterobacter agglomerans were studied and compared with the genomes of several Rahnella aquatilis strains as well as with one Pantoea agglomerans and one Ent. agglomerans referen ce strains, obtained from different world collections; they all were p reviously assumed to be related to this group of natural isolates. By using the infrequently cutting restriction endonuclease XbaI, highly c hracteristic fingerprints were obtained for each of the studied strain s except two Ent. agglomerans isolates which had identical fingerprint s. By hybridization of the resulting individual PFGE-fingerprints with a rDNA probe, containing the rrnB ribosomal RNA operon of Escherichia coli, the relationship between the analysed strains was studied. It w as shown that the natural isolates are very closely related to the typ e strain of R. aquatilis-ATCC 33071. The genome sizes of all studied s trains were estimated to be between 4.4 and 5.8 Mb on the basis of the lengths of their XbaI fragments. By a modification of the PFGE techni que it was shown that the analysed strains harbour one to three large and extra large plasmids with sizes in the range 90 to 608 kb.