Phylogenomic analyses and distribution of terpene synthases among <i>Streptomyces</i>

Terpene synthases are widely distributed among microorganisms and have been mainly studied in members of the genus <i>Streptomyces</i>. However, little is known about the distribution and evolution of the genes for terpene synthases. Here, we performed whole-genome based phylogenetic analysis of <i>Streptomyces</i> species, and compared the distribution of terpene synthase genes among them. Overall, our study revealed that ten major types of terpene synthases are present within the genus <i>Streptomyces</i>, namely those for geosmin, 2-methylisoborneol, <i>epi</i>-isozizaene, 7-<i>epi</i>-α-eudesmol, <i>epi</i>-cubenol, caryolan-1-ol, cyclooctat-9-en-7-ol, isoafricanol, pentalenene and α-amorphene. The <i>Streptomyces</i> species divide in three phylogenetic groups based on their whole genomes for which the distribution of the ten terpene synthases was analysed. Geosmin synthases were the most widely distributed and were found to be evolutionary positively selected. Other terpene synthases were found to be specific for one of the three clades or a subclade within the genus <i>Streptomyces</i>. A phylogenetic analysis of the most widely distributed classes of <i>Streptomyces</i> terpene synthases in comparison to the phylogenomic analysis of this genus is discussed.