title: The porphyrin pigmentation of subspecies of Bacteroides melaninogenicus.
abstract: Various subspecies of Bacteroides melaninogenicus differ in their pigmentation. Subsp. asaccharolyticus produces protohaem almost exclusively, subsp. intermedicus both protohaem and a smaller proportion of protoporphyrin, and subsp. melaninogenicus mainly protoporphyrin with a trace of protohaem. As a consequence young colonies can be differentiated by their red fluorescence in u.v. light (365nm): subsp. asaccharolyticus does not fluoresce, subsp. intermedicus shows a limited fluorescence, and subsp. melaninogenicus shows a bright fluorescence. The pigments were isolated as the dimethyl esters of protohaemin and of protoporphyrin and identified by electronic spectroscopy, mass spectrometry and comparisons by t.l.c. Incorporation of delta-aminolaevulinate into these pigments was not detected, nor was porphobilinogen formation observed. Subsp. melaninogenicus grown in the presence of [14C]protohaemin formed [14C]protoporphyrin. This appears to represent a novel biological demetallation.
mesh_terms: D001439:Bacteroides / Q000378:metabolism*; D006418:Heme / Q000096:biosynthesis; D010858:Pigmentation; D011166:Porphyrins / Q000378:metabolism*; D001443:Prevotella melaninogenica / Q000378:metabolism*; D011524:Protoporphyrins / Q000096:biosynthesis; D013045:Species Specificity; D013056:Spectrophotometry, Ultraviolet
chemical_list: D011166:Porphyrins; D011524:Protoporphyrins; D006418:Heme