Abstract
Lactic acid bacilli used for microbiological determinations all receive growth inhibition by 3.25-30.0 μg/ml of Lincomycin so that the parent strain cannot be used in the determination of vitamins in the presence of Lincomycin. If these lactobacilli are serially cultured in the medium containing increasing amount of Lincomycin, they can tolerate up to 2000 μg/ml of Lincomycin. The vitamin requirements of this resistant strain is almost the same as that in the parent strain. It was thereby found that the calibration curve will be entirely unaffected by the use of this resistant strain, even in the presence of 300-400 μg/ml of Lincomycin. Satisfactory results were obtained in the determination of urinary vitamins in patients administered Lincomycin, which had been impossible using the parent strain.
