Isolation, Characterisation and Phylogenetic Affiliation of Bioactive Endophytic Streptomyces sp. Associated with Medicinal Plants; [Pemencilan, Pencirian dan Afiliasi Filogenetik Endofit Streptomyces sp. Bioaktif daripada Pokok yang Mempunyai Nilai Perubatan]

• Published in: Sains Malaysiana
• Main Author: Sarmin N.I.M.; Zin N.M.
• Format: Article
• Language: Malay
• Published: Penerbit Universiti Kebangsaan Malaysia 2024
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85210950362&doi=10.17576%2fjsm-2024-5311-18&partnerID=40&md5=5e68191d52d326b920d89ba64f042c28

The high biodiversity of plant species in Malaysian forests provides a suitable environment for the isolation of endophytic Streptomyces. Novel strains of Streptomyces are potential sources for producing bioactive pharmaceutical compounds that can be developed as new drug candidates. This study aims to isolate the endophytic Streptomyces from different medicinal plants in the Bangi Reserve Forest before identification, characterisation, and phylogenetic analysis of the isolates. The endophytic actinomycetes were isolated using surface-sterilization method and further identified through morphological observation. The isolated endophytic Streptomyces were classified based on the colour of aerial mycelium. 16S rRNA gene sequence analysis was done to define the phylogenetic relationships among closely related species and strains belonging to a species. All isolates were then tested for their antimicrobial activities. Three endophytic Streptomyces, SUK 8, SUK 10 and SUK 15 were successfully isolated from different medicinal plants. These three isolates were classified into a grey series group based on the colour of aerial mycelium. The grey series also formed the same phylogenetic clade based on the 16S rRNA sequence data. Phylogenetic analysis of 16S rRNA gene sequences showed all three isolates were classified as Streptomyces eurythermus ATCC 14975T (gene sequence similarity 98.5%). Isolates of SUK 8, SUK 10 and SUK 15 also showed similar patterns of biological activities with inhibition of up to 100% of the same pathogenic organisms. These findings proved a good correlation between the diversity of the antimicrobial phenotype and the 16S rRNA gene. In conclusion, the potential of active metabolites from endophytic Streptomyces can be expected from a good source of taxonomy data. © 2024 Penerbit Universiti Kebangsaan Malaysia. All rights reserved.