2015 Volume 64 Issue 5 Pages 527-533
To address the needs and problems of plate media for the identification of fermentative, nonfermentative, and pure cultures of Gram-negative bacilli, we have prepared an experimental medium. The medium was prepared by dissolving 11 g of agar, 5 g of NaCl, 8 g of Gelysate peptone, 0.5 g of heart infusion broth, and 0.5 g of liver broth in 970 mL of purified water while heating. Then, 2.1 mL of 41.7% dipotassium hydrogen phosphate solution and 10 mL of 0.2% phenol red solution were added, and the resultant mixture was autoclaved at 115ºC for 15 min. When the medium temperature reached approximately 50ºC, a sterile cysteine/sugar solution was added. The composition of the cysteine/sugar solution was as follows: 0.2 g of L-cysteine, 1.5 g of D-glucose, 0.5 g of sucrose, 0.5 g of D(−)-mannitol, 0.25 g of L(+)-arabinose, and 0.25 g of D(−)-sorbitol, in a total volume of 20 mL. After stirring well, 20 mL of the medium was dispensed in a petri dish for use. In the observation of acid production from growing colonies, a satisfactory test result was obtained for pure cultures and the identification of fermentative and nonfermentative bacteria.