Abstract
When Candida albicans and Lactobacillus acidophilus are inoculated simultaneously on a 1% glucose-added BHI medium so that the total cell number of both species becomes 105-6 cells/ml and mixed culture carried out, Lactobacillus survives for a comparatively long time although it increases and decreases in cell number markedly. On the contrary, Candida grows regardless of the presence of Lactobacillus, showing its characteristic growth curve. The change in the cell number of these organisms during the period of mixed culture is related to the accumulation of the metabolic substances such as alcohol or lactic acid in the medium. But even if the growing medium, the quantity of the inoculated organisms, the time of inoculation, or the ratio of mixture of inoculated species were changed, a similar result in the cell number is observed in many cases. If the antibiotic such as erythromycin or trichomycin is added to this mixed culture to the degree that the growth of Candida and Lactobacillus is not disturbed so much, it acts advantageously for Candida, but not for Lactobacillus. It is, therefore, considered that a complicated change in the cell number is observed because of symbiosis and antibiosis between the two organisms, when Candida and Lactobacillus co-exist in the same circumstance. It is suggested that this is related not only to the size, shape and the metabolic system of the organisms, but also to the condition of the growing medium and the ratio of the quantity of the inoculated organisms.
