Preston Manwill, Southern Utah University
Life Sciences
Members of Anthoxanthum (sweetgrass) have a history of ceremonial and medicinal use. Coumarin, a secondary metabolite produced by the grass, is an anticoagulant and antimicrobial agent. Antimicrobial properties of commercially available European A. odoratum metabolites have been nominally investigated, but no North American species have been studied. Additionally, European sweetgrass is purported to be available in both diploid and polyploid strains. Our research objectives were to: 1) determine if ploidy level strains do exist, and 2) investigate secondary metabolite production and evolution in commercial strains and A. hirtum, a Great Basin native. Using epidermal casts and fuschin staining, differences in guard cells and nuclei were surveyed. Secondary metabolites from the A. odoratum strains and A. hirtum were obtained through steam distillation and a vacufugation protocol that concentrated hydrosols. GC/MS analyses characterized and quantified secondary metabolites. The secondary metabolites coumarin, dihydrobenzofuron, and dihydroactinidiolide were identified, with the first and latter greatest in A. hirtum. Significant guard cell differences between strains, as well as species, were observed. Two ploidy strains of A. odoratum were suggested. A Kirby-Bauer assay tested presence, size and retention of inhibition zones (IZ) produced against soil bacteria. Gram-staining initially characterized bacterial morphs. Secondary metabolites from the diploid strain were most effective against all bacterial morphs, but polyploid metabolites also generated and retained IZ against diploid root associated and non-root associated morphs. The native sweetgrass produced IZ only against root associated bacteria with which it had evolved. Future work will include similar studies of other North American Anthoxanthum species.