Antimicrobial potential of bacterial endophytes that inhabit New Zealands medicinal plant <i>Pseudowintera colorata</i>

Abstract

Medicinal plants are valued for the naturally bioactive compounds they produce International research has demonstrated that these plants contain endophytic microorganisms that through close interaction with the plants physiology contribute to the production of host metabolites either directly or via involvement in biochemical pathways Some endophytes can produce bioactive compounds that are either the same or similar to those originating from their host plants Pseudowintera colorata (horopito or NZ pepper tree) an endemic New Zealand plant used in traditional Maori medicine (rongo?) is recognised for its antimicrobial properties The biologically active chemical constituent polygodial is used for treating candidiasis A total of 340 endophytic bacteria were recovered from surface sterilised horopito leaves stems and roots from nine sites across New Zealand; strains were assessed for their ability to inhibit the phytopathogens Neofusicoccum parvum N luteum Ilyonectria liriodendri Nectria galligena Pectobacterium atrosepticum and P brasiliensis using a dual culture assay Inhibition zones 1048726;3 mm were considered a positive result Out of the strains tested seven showed activity against all the phytopathogenic fungi tested and ten strains were active against at least three phytopathogens Future work will determine if any of the endophytic bacteria produce polygodial