The sensitivity of a local Lebanese yogurt culture to different antibiotics was checked, using either a fresh or a freeze-dried culture. Laban fermentation was significantly affected by 0.005 IU of penicillin/ml, 1μg of streptomycin/ml, 1μg of dihydrostreptomycin/ml, 10 μg of chloramphenicol/ml and a level of oxytetracycline between 0.05 and 0.5 μg/ml. Although the method was not standardized, it was used to check 858 milk samples in Lebanon of which 11.20% were found to contain lactic acid bacterial inhibitory substances.
1Paper No. 549B in the Scientific Journal Series, Faculty of Agricultural and Food Sciences, American University of Beirut, July 1980.
2Supported in part by a research grant from the National Council for Scientific Research, Lebanon.
3Present address: Animal Production and Health Section, Regional Agriculture and Water Research Center. P.O. Box 8784, Riyadh, Saudi Arabia.