title: Chromogenicity of Streptomyces.
abstract: A simplified technique to detect polyphenol oxidase and melanin formation by Streptomyces culture filtrates was developed. The procedure involves the direct assay of pigment formation by the culture filtrate with 3-(3,4-dihydroxyphenyl)-L-alanine (L-dopa) as a substrate. Among cultures of the International Streptomyces Project, 34 failed to produce a diffusible dark brown pigment on peptone-yeast extract-iron-agar and synthetic tyrosine-agar and gave a negative reaction to the melanin formation test. Sixteen cultures produced a diffusible dark brown pigment on both peptone-yeast extract-iron-agar and synthetic tyrosine-agar and gave positive reactions to the test with either L-tyrosine or L-dopa as substrate. Twenty-one cultures produced a diffusible dark brown pigment on peptone-yeast extract-iron-agar, but failed to do so on synthetic tyrosine-agar. Most of these cultures gave a positive reaction to the test when L-dopa was used as the substrate. The correlation between chromogenicity on complex organic media and melanin formation was more clearly established with L-dopa as substrate than with synthetic tyrosine-agar in the present test. The melanin formation test by the present technique, instead of chromogenicity on complex organic media, is recommended as a key feature for the classification of Streptomyces.
mesh_terms: D000362:Agar; D000596:Amino Acids / Q000378:metabolism; D001431:Bacteriological Techniques; D050260:Carbohydrate Metabolism; D004156:Catechol Oxidase / Q000096:biosynthesis; D003470:Culture Media; D004295:Dihydroxyphenylalanine; D005971:Glutamates / Q000378:metabolism; D007501:Iron; D008543:Melanins / Q000096:biosynthesis*; D010461:Peptones; D010936:Plant Extracts; D012440:Saccharomyces; D013045:Species Specificity; D013053:Spectrophotometry; D013302:Streptomyces / Q000145:classification / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D014443:Tyrosine
chemical_list: D000596:Amino Acids; D003470:Culture Media; D005971:Glutamates; D008543:Melanins; D010461:Peptones; D010936:Plant Extracts; D014443:Tyrosine; D004295:Dihydroxyphenylalanine; D000362:Agar; D007501:Iron; D004156:Catechol Oxidase