A New Selective Medium for the Isolation and the Detection of Leuconostocs in Foodstuffs

식품중에 함유된 Leuconostocs 균주의 새로운 선택배지 개발

  • Choi, Hak-Jong (Department of Biological Resources and Technology, Yonsei University) ;
  • Shin, Young-Jae (Department of Biological Resources and Technology, Yonsei University) ;
  • Yu, Ju-Hyun (Department of Food and Biotechnology, yonsei University) ;
  • Yoon, Sung-Sik (Department of Biological Resources and Technology, Yonsei University)
  • 최학종 (연세대학교 생물자원공학과) ;
  • 신영재 (연세대학교 생물자원공학과) ;
  • 유주현 (연세대학교 식품생물공학과) ;
  • 윤성식 (연세대학교 생물자원공학과)
  • Published : 1996.04.30

Abstract

To develop a selective medium for the isolation and the detection of leuconostocs from the various samples including fermented vegetables, ten strains of leuconostocs and seven strains of lactobacilli were tested for their sensitivity to various antibiotics. The basal-medium containing 5 ${\mu}g/ml$ of novobiocin inhibited the growth of lactobacilli completely, but not that of leuconostocs. On the basis of this result, a new selective medium was developed and to be named NLS medium. This medium contains 1% Tryptone (Difco), 0.1% Yeast Extract (Difco), 2% sucrose, 0.1% Beef Extract (BBL), 0.5% sodium acetate, 0.2% ammonium sulfate, 0.01% magnesium sulfate, 0.2% dipotassium phosphate, 0.05% sorbic acid, 75 ppm sodium azide (Sigma), 0.1% (vol/vol) Tween 80, 30 ${\mu}g/ml$ of Vancomycin (Sigma), 5${\mu}g/ml$ of Novobiocin (Sigma), 0.5${\mu}g/ml$ of cysteine HCI, and 1.5% Agar (Difco). All of the eighty six isolates obtained from some foodstuffs were identified as members of the genus Leuconostoc. Comparative counts with the MRS, PES, LUSM, and NLS medium indicated that the recovery percent was lower than other selective media. Therefore, this result suggested that NLS medium was suitable for the isolation of leuconostocs, but not for counting or enumerating.