青海盐碱环境中具抗肿瘤活性放线菌的筛选和多样性研究

Micirobial diversity and screening of antitumor activity of actinomycete strains from saline and alkaline environments in the Qinghai Province,P.R.China

摘要:

从我国青海省采集盐碱土样或泥样,用添加1.0~3.0mol/L NaCl的GPY琼脂培养基和ISP2琼脂培养基分离到145株典型放线菌菌株。采用6种肿瘤细胞株对分离菌株的发酵产物进行体外筛选,得到26株抗肿瘤活性阳性菌株(17.9%),19株为拟诺卡氏属(Nocardiopsis)菌株,7株为链霉菌属(Streptomyces)菌株。在抗肿瘤活性、形态特征、生理生化特性和全细胞水解物氨基酸组分分析等实验结果的基础上,选取差异较大的8株抗肿瘤活性阳性菌株进行16S rRNA基因序列测定和系统发育多样性分析。结果表明,2株属于链霉菌属(Streptomyces)的1个已知物种和1个潜在新种;6株属于拟诺卡氏菌属(Nocardiopsis),可能代表该属的4个新种。研究表明青海盐碱环境中存在产生抗肿瘤活性物质的重要放线菌资源,也提示其中蕴藏着较丰富的微生物多样性。

Abstract:

Soil and sediment samples were collected from saline and alkaline soils or lakes in the Qinghai Province，northwestern China. 145 actinomycete strains were isolated using Glucose-Peptone-Yeast extract agar (GPY) and ISP medium 2 agar supplemented with 1.0～3.0mol/L NaCl at pH 7.5～10. The antitumor activities in vitro of the fermentation broth extracts from the 145 test strains were detected in 6 human tumor cell lines (gastric cancer GXF251L，lung cancer LXFL529L，mammary cancer MAXF401NL，melanoma cancer MEXF462NL，renal cancer RXF486L and uterus cancer UXF1138L). Out of 145 test strains，26 strains were positive in antitumor activities（17.9%），among them 19 strains belong to the genus Nocardiopsis，7 strains belong to the genus Streptomyces. Then 8 antitumor-positive strains were submitted for 16S rRNA gene amplification and phylogenetic analysis after a comparison of antitumor activities，morphological，physiological characteristics and whole cell amino acids analysis. The results suggested that strain YIM 80139 is a member of a known Streptomyces species S. griseus，while strain YIM 80038 may represent a potential new Streptomyce species，and that the other 6 strains may represent 4 potential new species of the genus Nocardiopsis. The results presented above showed that actinomycetes isolated from saline and alkaline samples are important resources for bioactive compounds，and the abundant microbial diversity in the saline and alkaline environments in the Qinghai Province，Northwestern China is attractive for further investigation.