1. Antitumour and antimicrobial activities of endophytic streptomycetes from pharmaceutical plants in rainforest.
- Author
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Li, J., Zhao, G. -Z., Chen, H. -H., Wang, H. -B., Qin, S., Zhu, W. -Y., Xu, L. -H., Jiang, C. -L., and Li, W. -J.
- Subjects
ANTI-infective agents ,ANTINEOPLASTIC agents ,ENDOPHYTES ,BIOSYNTHESIS ,RAIN forests ,STREPTOMYCES ,ACTINOBACTERIA ,DRUG factories ,BIOACTIVE compounds - Abstract
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. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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