ENTEROBACTER-PYRINUS SP-NOV, AN ORGANISM ASSOCIATED WITH BROWN LEAF-SPOT DISEASE OF PEAR TREES

A new species, Enterobacter pyrinus, which was isolated from brown leaf spot lesions on pear trees, is described on the basis of the characteristics of seven strains. These bacteria are gram-negative, facultatively anaerobic, straight rods (0.6 to 1.0 by 1.6 to 2.3 mum) that are motile and peritrichous. As determined by DNA hybridization (hydroxyapatite method), these seven strains were 97.5% related in both 60 and 75-degrees-C reactions, with no evidence of sequence divergence, indicating that they are members of a single species. E. pyrinus is most closely related to Enterobacter gergoviae (46%) and to Enterobacter agglomerans hybridization group XI (37%). E. pyrinus is differentiated from E. gergoviae by its growth in KCN broth, acid production from myo-inositol, and lack of acid production from raffinose. The type strain of E. pyrinus is strain KCTC 2520 (= CDC G6570 = ATCC 49851).