Isolation of Novel Actinomycetes from Spider Materials

To collect new kinds of microorganisms for screening of biologically active substances, we focused on spider materials (webs, cuticle, egg sac), previously uninvestigated sources of such organisms. Using a new method of pre-treatment with 70% ethanol, 1,159 strains of actinomycetes were isolated from 196 spider materials, based on their morphological features. Of these, 293 strains were identified as non-filamentous actinomycetes from their 16S rRNA gene sequences. More detailed examination indicated that 139 strains belonged to the suborders Micrococcineae, Frankineae and Propionibacterineae, and they included some novel strains of non-filamentous actinomycetes. Thus, spider materials provide a more useful source of non-filamentous actinomycetes than do soil samples.