Endophytic fungi from medicinal herb Salvia miltiorrhiza Bunge and their antimicrobial activity

A total of 57 endophytic fungal isolates were obtained from the roots of Salvia miltiorrhiza Bunge (Lamiaceae). Fourteen (14) distinct isolates were selected for further taxonomical identification by morphological traits and internal transcribed spacer (ITS) rRNA gene sequence analysis. Twelve (12) genera were identified among which Alternaria and Fusarium were dominants. Eight endophytic fungi (that is, Pleosporales sp. Samif02, Leptosphaeria sp. Samif03, Peyronellaea glomerata Samif04, Xylomelasma sp. Samif07, Bionectria ochroleuca Samif08, Sarocladium kiliense Samif11, Petriella setifera Samif13 and Cadophora sp. Samif14) were separated as the endophytic fungi from S. miltiorrhiza for the first time. Most of the fungal isolates were observed to have antibacterial activity that suggests antibacterial compounds mainly exist in mycelia. The ethyl acetate extracts of Alternaria sp. Samif01, Xylomelasma sp. Samif07, Fusarium redolens Samif09, Sarocladium kiliense Samif11 and Petriella setifera Samif13 were also observed to have antifungal activity. Among the isolates, Alternaria sp. Samif01 and Sarocladium kiliense Samif11 were found to have strong antibacterial and antifungal activities. The results indicate that there is a diversity of the endophytic fungi from S. miltiorrhiza, and these endophytic fungi could be an excellent resource for searching natural antimicrobial compounds.   Key words: Salvia miltiorrhiza Bunge, endophytic fungi, ethyl acetate extracts, antimicrobial activity, antimicrobial compounds.