Abstract
Rhizobacter dauci from gall tissue formed on carrot roots was successfully isolated with the preparation of a bacterial suspension using thin sections of gall tissue, immediately followed by dilution plating method in 10-fold dilution of potato-peptoneglucose (DPPG) agar medium. It could not be isolated by macerating gall tissue in a mortar, partly because of the overgrowth of other microorganisms. R. dauci colonies showed continuous growth for more than 7 days at a low culture density on a DPPGA plate. R. dauci cells in distilled water died 30 minutes after beeing suspended in water, whereas they lived for at least 3 hr when suspended in DPPG broth. Pit formation around R. dauci colonies was constantly observed under a microscope at low magnifi cation at the early stage of culture on the DPPGA plate. This phenomenon was sup posed to reflect the feasible use of agar as a carbon source.
