AIMS: The aim of this study was to screen antitumour and antimicrobial activities of endophytic actinomycetes isolated from pharmaceutical plants in rainforest in Yunnan province, China. METHODS AND RESULTS: Antitumour activity was studied by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and antimicrobial activity was determined by agar well diffusion method. The high bioactive endophytic isolates were identified and further investigated for the presence of polyketide synthases (PKS-I, PKS-II) and nonribosomal peptide synthetases (NRPS) sequences by specific amplification. The molecular identification confirmed that the 41 isolates showed significant activities were members of the genus Streptomyces. Among them, 31.7% of endophytic streptomycete cultures were cytotoxic against A549 cells, 29.3% against HL-60 cells, 85.4% against BEL-7404 cells, 90.2% against P388D1 cells, 65.9% were active against Escherichia coli, 24.4% against Staphylococcus aureus, 31.7% against Staphylococcus epidermidis, 12.2% against Candida albicans and no strain displayed antagonistic activity against Klebsiella pneumoniae. High frequencies of positive PCR amplification were obtained for PKS-I (34.1%), PKS-II (63.4%) and NRPS (61.0%) biosynthetic systems. CONCLUSIONS: Many endophytic streptomycetes isolated from pharmaceutical plants in rainforest possess remarkable and diverse antitumour and antimicrobial bioactivities. SIGNIFICANCE AND IMPACT OF THE STUDY: These endophytic streptomycetes are precious resources obtained from rainforests, and they could be a promising source for bioactive agents.
AIMS: The aim of this study was to screen antitumour and antimicrobial activities of endophytic actinomycetes isolated from pharmaceutical plants in rainforest in Yunnan province, China. METHODS AND RESULTS: Antitumour activity was studied by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and antimicrobial activity was determined by agar well diffusion method. The high bioactive endophytic isolates were identified and further investigated for the presence of polyketide synthases (PKS-I, PKS-II) and nonribosomal peptide synthetases (NRPS) sequences by specific amplification. The molecular identification confirmed that the 41 isolates showed significant activities were members of the genus Streptomyces. Among them, 31.7% of endophytic streptomycete cultures were cytotoxic against A549 cells, 29.3% against HL-60 cells, 85.4% against BEL-7404 cells, 90.2% against P388D1 cells, 65.9% were active against Escherichia coli, 24.4% against Staphylococcus aureus, 31.7% against Staphylococcus epidermidis, 12.2% against Candida albicans and no strain displayed antagonistic activity against Klebsiella pneumoniae. High frequencies of positive PCR amplification were obtained for PKS-I (34.1%), PKS-II (63.4%) and NRPS (61.0%) biosynthetic systems. CONCLUSIONS: Many endophytic streptomycetes isolated from pharmaceutical plants in rainforest possess remarkable and diverse antitumour and antimicrobial bioactivities. SIGNIFICANCE AND IMPACT OF THE STUDY: These endophytic streptomycetes are precious resources obtained from rainforests, and they could be a promising source for bioactive agents.
Authors: Rajesh P Shastry; Martin Welch; V Ravishankar Rai; Sudeep D Ghate; K Sandeep; P D Rekha Journal: Arch Microbiol Date: 2020-03-12 Impact factor: 2.552
Authors: Mohsin T Cheema; Larissa V Ponomareva; Tao Liu; S Randal Voss; Jon S Thorson; Khaled A Shaaban; Imran Sajid Journal: Curr Microbiol Date: 2021-06-14 Impact factor: 2.188
Authors: Mariana Recco Pimentel; Gustavo Molina; Ana Paula Dionísio; Mário Roberto Maróstica Junior; Gláucia Maria Pastore Journal: Biotechnol Res Int Date: 2010-09-26