Abstract
The effects of certain vitamins on the cell multiplication on Lactobacillus delbrueckii No. 1 were studied.
According to their effects on cell multiplication, the growth-essential vitamins may be divided into three groups. (a) The vitamins, whose deficiency cause the cease of cell growth. Niacin and pantothenic acid belong to this group. (b) The vitamins, whose deficiency in certain concentration range cause the inhibition of cell division without affecting cell growth. Vitamin B12 and folic acid belong to this group. (c) The vitamins which have an influence on cell division in combination with other vitamins. Riboflavin belongs to this group.
It was further demonstrated that for the normal cell multiplication of this organism a certain ratio in the supplied vitamins in the medium was required. Even though the amounts of added vitamins and bases were sufficient, the cell multiplication of L. delbrueckii did not take place satisfactorily, unless the ratio of the vitamins and bases was suitably balanced.
