Isolation, identification and characterization of endophytes from the medicinal plant Echinacea: new sources of bioactive compouns with medical and/or pharmaceutical applications

Research in the aea of herbal pharmacology has revealed a variety of promising medicins that may provide benefit in diverse treatments. The therapeutic properties of medicinal plants are therefore likely related to their endophytic communities too. Endophytes provide an abundant reservoir of bioactive metabolites for medicinalexplotation. In this study we analysed the bacterial communities isolated from the medicinal plant Echinacea purpurea. Aims of his work were to: a) study the structure (via RAPD analysis) and composition (via 16S rRNA analysis) of endophytic communities; b) check their ability to growin presence of antibiotics, heavy metals, H2O2 and diesel fuel; c) identify strains with antimicrobial activity. Data revealed that the bacterial communities iolated from distinct compartments exhibited a dfferent degree of biodiversity at genus/species level and/or strain level. The also showed a different physiology, e.g. strains from roots are much resistant to antibiotics while those from stem/leaf show a better growth rate in presence of H2O2. Interestingly, cross-streaking tests using different Cystic Fibrosis (opportunistic) pathogens as targets (Burkholderia sp., Staphylococcus aureus and Pseuomonas aeruginosa) revealed that some endophytic strain were able to inhibit the growth of these pathogens. Data highlighted that endophytes from E. purpurea might represent a new source of natural bioactive compounds withmedical/pharmaceutical and/or biotchnological applications.