porphobilinogen and porphyrin synthesis , apparently via the commonly known heme synthesis pathway , occurred during growth of heme-independent b. ruminicola subsp . brevis strain ga33 in a tetrapyrrole-free medium containing delta-aminolevulinic acid , but delta-aminolevulinic acid metabolism to porphobilinogen or porphyrins could not be detected in cells of heme-requiring strain 23 grown in the same medium with hemin added .
C0018966
heme
C0018988
hemin