Isolation and characterization of actinomycetes from Brazilian tropical soils

Actinomycetes have been isolated from three Brazilian tropical soils. The d ispersion and differential centrifugation procedure revealed count values 1 .5 to 5.0 times greater than those obtained by the conventional dilution pl ate technique for all soils and media tested. Eighteen strains, promising f or biotechnological applications, were submitted to chemotaxonomic procedur es and numerical taxonomy for identification. Two were identified as Amycol atopsis orientalis, one as Streptomyces misakiensis, and two tentatively in cluded or associated to S. chromofuscus and S, griseoruber. The others, all belonging to the Streptomyces genus, could not be fitted into any known sp ecies, and were arranged by the UPGMA analysis for classification, as an is olated group. This suggests that the actinomycetes in tropical soils may re present a vast unexplored resource for biotechnology.