南方红豆杉内生及根际放线菌多样性及其生物活性

【目的】研究药用植物南方红豆杉内生及根际土壤放线菌的多样性及其抑菌、抗肿瘤等重要生物活性并获得一些具有强抑制植物病原真菌以及抗肿瘤等重要生物活性的菌株。【方法】选择7种培养基从南方红豆杉及其根际土壤中分离放线菌,对链霉菌进行形态学分类,去重复后对其进行抑制植物病原真菌以及抗肿瘤活性的筛选并对高活性菌株进行初步鉴定。对部分菌株进行16S rRNA基因测序分析研究其多样性。【结果】研究共分离得到277株放线菌,经去重复后剩余111株放线菌,可归类到6个亚目、7个科、8个属。其中链霉菌可分为10个类群。生物活性研究结果显示:30.9%的菌株具有抑制植物病原真菌活性,其中6株放线菌对多种植物病原真菌显示了强的抑菌活性。分别有44.1%和33.3%的菌株对胃癌肿瘤细胞株SGC-7901和肺癌肿瘤细胞株NCI-H460的抑制率在40%以上。【结论】药用植物南方红豆杉及其根际土壤蕴含种类丰富的放线菌资源,具有良好的生物学活性。菌株KLBMP 2170具有显著的抑菌以及抗肿瘤活性,值得我们去进一步研究。

Diversity and bioactivity of actinomycetes isolated from medicinal plant Taxus chinensis and rhizospheric soil

Objective] In order to provide strains with high activity of anti-phytopathogenic fungi and antitumor activity, we studied the diversity and bioactivity of actinomycetes isolated from medicinal plant Taxus chinensis and rhizospheric soil. Methods] Seven selective media were used to isolate actinomycetes. Experiments of anti-phytopathogenic fungi, cytotoxicity activity, and the 16S rRNA gene sequencing of them were carried out to evaluate the diversity and bioactivity. Strains with high activity were identified. Results] A total of 277 actinomycetes were isolated, of which 111 strains were selected and assigned to 6 suborders, 7 families and 8 genera, in which Taxus chinensis can be divided into 10 groups. The bioactivity testing results indicated that: 30.9% isolates showed activity against at least one of the 12 phytopathogenic fungi; 44.1% strains and 33.3% strains showed cytotoxicity activity with inhibition rate above 40% against stomach cancer cell line SGC-7901 and lung cancer cell line NCI-H460 respectively. Conclusion] Actinomycetes isolated from Taxus chinensis and rhizospheric soil is of high diversity and a good source for the selection of bioactive compounds. Taxus chinensis KLBMP 2170 is an excellent resource with antifungal and cytotoxicity activity for further studies.