Diverse endophytic bacteria isolated from a leguminous tree Conzattia multiflora grown in Mexico

Conzattia multiflora is a leguminous tree present only in Mexico and Guatemala. There is no record about its symbiotic or pathogenic microbes. In this study, we found that numerous bacteria with 10⁴-10⁶ individuals per gram of fresh epidermis were distributed in the tissue of this plant. All the bacteria isolated from the Conzattia epidermis were Gram-negative, facultative anaerobic rods and formed yellow or colorless colonies. They were identified as endophytes by inoculation tests. Some of the bacteria could significantly promote the growth of Conzattia seedlings. Nine different groups were defined by PCR-based RFLP, which were classified as Pantoea, Erwinia, Salmonella, Enterobacter, Citrobacter and Klebsiella by the phylogenetic analysis of 16S rRNA genes. The existence of plant-borne lineages of Salmonella indicates that the unexplored plants may harbor some unknown microbes.