1982 Volume 51 Issue 1 Pages 40-45
Investigation was made on the effect of B vitamins added to the artificial diet on the pathogenicity of Streptococcus faecalis to silkworm larvae.
S. faecalis M-8 was low pathogenic to larvae reared on the basal artificial diet without any B vitamin. The pathogenicity of S. faecalis M-8 increased markedly in the larva reared on the diet innluding nicotinic acid, folic acid or biotin. The minimal optimal amount of B vitamins (ng/ml) required for the growth of S. faecalis was determined: Nicotinic acid; 25-250, folic acid; 0.5-2.5, biotin: 1.0-2.0. pantothenic acid; 50-150, pyridoxine; 1.0.
The variable pathogenicity of S. faecalis to the larva reared on an artificial diet was discussed in relation to the minimal optimal amount of B vitamins required for the growth of the bacteria and the amount contained in the artificial diet.
