Taxonomic Diversity of Actinomycetes Isolated from Swine Manure Compost

In this study, we investigated the taxonomic diversity of actinomycetes isolated from swine manure compost that had undergone self-heating. Pretreatment with sodium dodecyl sulfate and subsequent cultivation of the compost sample on humic acid-vitamin agar at 30 and 50°C resulted in the selective isolation of 125 actinomycete strains. These isolates were classified using a combination of morphological characterization and 16S rDNA sequence analysis, with sequence similarities of ≥97% and ≥99% used to identify isolates at genus and species level, respectively. The isolated actinomycete assemblage consisted of a diverse array of species, with the 125 isolates falling into 10 families, 15 genera, and 22 species. The most dominant thermophilic actinomycetes were Saccharomonospora (Sam.) viridis and Thermobifida fusca, followed by Actinomadura spp. Other species that were frequently isolated at 30°C included Glycomyces spp., Nocardiopsis (Nop.) alba, Nop. composta, Rhodococcus rhodochrous, and Sam. azurea.