김치에서 분리한 Lactobacillus sp. JC-7과 Lactobacillus acidophilus 88간의 Electrofusion 최적조건 설정 = Evaluation of Optimum Conditions for the Electrofusion between Lactobacillus sp. JC-7 Isolated from Kimchi and Lactobacillus acidophilus 88

국문 초록 (Abstract)

김치 발효 숙성기간을 연장하고 신선도를 오랫동안 유지 할 수 있는 김치발효 starter의 개발을 목적으로 최적숙성기에 있는 김치로부터 bacteriocin생성능이 없는 유산균을 분리하여 동정하였으며,
bacteriocin생성능이 우수한 L.acidophilus 88을 융합시키기 위해 electrofusion에 대한 최적 조건을 검토하였다. 분리균주는 Lactobacillus속으로 동정되어 Lactobacillus sp. JC-7이라 명명하였다. Electrofusion에 의해 생성된 융합주를 식별하기 위해 streptomycin(2.5㎎/ml)에 내성을 나타내는 Lactobacillus sp. JC-7변이주와 kanamycin(600㎍/ml)에 내성을 나타내는 L.acidophilus 88변이주를 분리하였다. Electrofusion을 100V/㎝, 120msec(72ohms,1670 capacitance) 에서 수행했을 때 융합효율이 가장 양호하였으며 전기장의 세기와 시간이 중가할수록 융합 효율이 현저히 감소하였다. 2가 양이온은 농도가 중가할수록 대체적으로 융합효율을 감소시키는 경향을 나타내었으나 1mM MGCl_2에서는 대조군에 비해 융합효율이 약간 증가하였다. PEG매개에 의한 융합법의 융합효율을 비교한 결과, 융합효율은 chemical fusion<electrofusion<electrofusion+20% PEG순을 나타내었다.

다국어 초록 (Multilingual Abstract)

Evaluation of Optimum Conditions for the Electrofusion between Lactobacillus sp. JC-7 Isolated from Kimchi and Lactobacillus acidophilus 88. Young-Bae Jo, Hyun-Jung Choi, Hyung-Suk Baik and Hong-Ki Jun*. Department of Microbiology, Pusan National University, Pusan 609-735,Korea-A lactic acid bacterium was isolated from kimchi. The isolated strain was identified as the genus Lactobacillus thrugh its morphological characteristics and named as Lactobacillus sp. JC-7. The optimum conditions for the electrofusion between streptomycin(2.5㎎/ml)resistant mutant of Lactobacillus acidophilus 88 and kanamycin(600㎍/ml) resistant mutant Lactobacillus sp. JC-7 were evaluated. The highest number of fusants were obtained at a capacitance value of 120msec(1670㎌), a field strength of 100V/㎝,and a pulse controller setting of 72Ω. The potimum pH of elecroporation buffer was 7.5 and the concentration of divalent cation was 1mM MG^2+. Electrofusants were efficiently obtained by addition 20% polyethylene glycol to electroporation buffer. The yield of fusion was better than that of using polyethylene glycol mediated chemical induction.