Identification of Lipstatin-Producing Ability in Streptomyces virginiae CBS 314.55 Using Dereplication Approach

Abstract

Streptomyces species are prolific producers of bioactive metabolites, such as β-lactone-containing lipstatin produced by Streptomyces toxytricini, an intermediate used in semi-synthetic process for production of anti-obesity drug orlistat. Understanding the distribution of identical or structurally similar molecules produced by a taxonomic group is of particular importance when trying to isolate novel biologically active compounds or strains producing known metabolites of medical importance with potentially improved properties. Until now, only two independent isolates of S. toxytricini species have been known to be producers of lipstatin. According to the current taxonomic criteria, S. toxytricini belongs to Streptomyces lavendulae phenotypic cluster. Taxonomy-based dereplication approach coupled with in vitro assay was applied to screen the S. lavendulae phenotypic cluster for production of lipstatin-like lipase inhibitors using synthetic p-nitrophenol derivatives of C4 and C16 lipids. Screening the available strains from public collections belonging to S. lavendulae phenotypic cluster, high lipase inhibitory activity was identified in the Streptomyces virginiae CBS 314.55 culture supernatants. HPLC and LC-MS/MS confirmed lipstatin production by a new Streptomyces species for the first time. We have demonstrated that the new lipstatin-producing strain S. virginiae morphologically and physiologically differs from S. toxytricini substantially; however, the production capacity of the newly identified lipstatin-producing species S. virginiae is comparable to S. toxytricini. We have thus demonstrated the effectiveness of a simple and affordable dereplication approach for identification of potentially novel and useful industrial strains available in public culture collections.

Keywords

• lipstatin
• Streptomyces virginiae
• dereplication
• lipase inhibitor