The function of CO
2-related growth-promoting effect in the orange-colored
Streptococcus bovis was investigated. In the defined medium, CO
2 requirement was very large compared with that in natural media. Most of
14CO
2 incorporated was detected in the protein part. On the other hand, in the Polypepton-yeast extract medium,
14CO
2 incorporation was extremely small and about 40% of the incorporated
14CO
2 was found in the lipid part.
Though
S. bovis required only biotin as an essential factor among the vitamins, in the Polypepton medium, some of unsaturated fatty acids and oleate-containing compounds could replace not only biotin but also CO
2 requirement, whereas, in the synthetic medium, these compounds could not replace CO
2 requirement. This result suggests that CO
2 takes part in synthesizing not only amino acids but also fatty acids.
S. bovis is sensitive to oxygen, but CO
2 or unsaturated fatty acids can be replaced by O
2 in natural media.
View full abstract