염색공단 주변의 토양과 하수로부터 아조염료 분해 탈색능이 우수한 MB2균을 분리하여 Citrobacter sp.로 동정하였다. Citrobacter sp. MB2의 성장 최적배지 및 배양조건은 sucrose 0.5%, yeast extract 1.0%, $K_2HPO_4$ 0.1%, $NaHCO_3$ 0.1%, pH 7.0, 배양온도 $30^{circ}C$에서 호기적 진탕배양이었으며, 최적배지에서의 균성장은 분리용 배지나 nutrient broth에서의 균성장보다 각각 7배 및 50배 이상 개체수가 증가하였다. Citrobacter sp MB2는 금속염에 대해 강한 내성을 보였으며, 항생제 ampcillin과 penicillin G에 대해서 강한 내성을 보였다.
A Citrobacter sp. MB 2, azo dyes decolorizing bacterium, was isolated from the wastewater and soil and identified as Citrobacter sp.. It was examined that optimum conditions for culture media were 0.5% of sucrose, 1.0% of yeast extract, 0.1% of $K_2HPO_4$, 0.1% of $NaHCO_3$ per distilled water. The best efficient condition of culture was obtained at pH 7.0, $30^{circ}C$ and aerobic shaking culture. The number of Citrobacter sp. MB2 in optimum medium was increased more than 7 fold compared to basal medium and 50 fold compared to nutrient broth. This strain was exhibited strong resistance against metal salts and antibiotics (ampicillin and penicillin G).
