TY - JOUR AU - Quang Huy, Nguyen AU - Thi Hanh Nguyen, Vu AU - Van The, Nguyen AU - Thi Lien, Bui AU - Thi Thu Hang, Le AU - Quyet Tien, Phi PY - 2020/11/02 Y2 - 2024/03/29 TI - Antimicrobial and cytotoxic effects of endophytic Streptomyces strains isolated from Cinnamomum cassia Presl in Vietnam JF - Vietnam Journal of Biotechnology JA - Vietnam J. Biotechnol. VL - 17 IS - 4 SE - Articles DO - 10.15625/1811-4989/17/4/14469 UR - https://vjs.ac.vn/index.php/vjbt/article/view/14469 SP - 757-766 AB - <p>Vietnam is recognized as one of the countries with the high diversity of medicinal plant species in the world, nevertheless little is known about the distribution, diversity and biological activity of endophytic actinomycetes associated with host plants. The present study aimed to evaluate antimicrobial and cytotoxic activities of four endophytic <em>Streptomyces </em>strains including <em>Streptomyces</em> sp. HBQ75, HBQ87, HBQ102 and HBQ104 isolated from different organs (roots, stems or leaves) of <em>Cinnamomum cassia </em>Presl. Analysis of 16S rRNA gene sequences and the phylogenetic tree assigned them to four different <em>Streptomyces </em>species as follow <em>Streptomyces fulvissimus </em>HBQ75, <em>Streptomyces parvulus </em>HBQ87, <em>Streptomyces pratensis </em>HBQ102 and <em>Streptomyces ribosidificus </em>HBQ104. These strains exhibited broad antimicrobial spectrum against at least five out of nine pathogens tested, among them <em>S. parvulus </em>HBQ87 showed the best activity (inhibition zones &gt;20 mm). Interestingly, <em>S. parvulus </em>HBQ87 carried all three genes (<em>pks</em>-I, <em>pks</em>-II and <em>nrps</em>) encoding for polyketide synthase or non-ribosomal peptide synthetase enzymes involved in biosynthesis of secondary metabolites, while the remaining strains only possessed one or two genes. All the <em>Streptomyces </em>strains were positive for the anthracyclines-like antibiotic activity. The cell-free supernatants of <em>S. parvulus </em>HBQ87 revealed remarkable inhibitory effects against all three human cacinomar cell lines including hepatoma Hep3B, breast adenocarcinoma MCF7 and lung cancer A549 cells at both concentrations tested (30 µg/mL and 100 µg/mL), while <em>S. fulvissimus </em>HBQ75 and <em>S. pratensis </em>HBQ102 were active against only Hep3B and MCF7 cells. In conclusion, the phenotypic and genotypic features of the four endophytic <em>Streptomyces</em> strains suggest that they have a capacity to produce different broad-spectrum secondary metabolites. Among them, <em>S. parvulus </em>HBQ87 could be the most potential candidate for the production of important antimicrobial and antitumor compounds.</p> ER -