i) inoculating P. carotovorum strain into a medium composition consisting of water, pectin, cellobiose, inositol, bile salt, bromocresol green, agar, yeast extract, and sodium chloride (NaCl) for selective detection of the P. carotovorum and then culturing the strain;

ii) checking a pattern or circles of color development of colonies formed in the selective medium composition after inoculation or culture in step i); and

iii) selectively isolating the colonies having a light yellow-colored center with a cyan-colored periphery surrounding the light yellow-colored center which indicate the P. carotovorum only.