ISSN:
1432-0789
Keywords:
Actinomycetes
;
Melanins
;
Growth media
;
Tropical soil
;
Streptomyces spp
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Geosciences
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary Melanogenic actinomycetes were isolated from cerrado soils. Starch agar with a neutral pH was the best medium for selecting pigment-producing colonies. A pigmentation screening test selected 52% of these as possible melanin producers. Tests on liquid (organic and inorganic) and solid (peptone and tyrosine) media, and enzymatic tests, confirmed about 90% as melanin producers, 68% as dihydroxyphenylalanine (DOPA)-melanin and 32% as possible other kinds of melanin producers. Melanin production occurred mostly with an organic N, or an inorganic N with an additional organic N source. An exception was observed with three strains, which were able to produce melanins with an entirely inorganic N source in the medium. Instability of melanin production was a common feature in many strains. Further characterization of melanins produced by actinomycetes compared with soil humic acids may clarify the possible role of melanogenic actinomycetes in soil organic matter formation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00361615
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