2株具抗菌活性的稀有放线菌的筛选和鉴定

Screening and identification of two rare Actinomycetes exhibiting antimicrobial activity

从药用植物根际土壤样品中分离得到了一批放线菌菌株，通过对其进行了抗茵活性筛选，发现菌株45725具有较好的抗耻垢分枝杆菌活性，菌株06-2230具有较强的抗绿脓杆菌活性。菌株45725和06-2230在酵母-麦芽膏琼脂（ISP2）、燕麦琼脂（ISP3）、无机盐淀粉琼脂培养基（ISP4）、葡萄糖天冬素琼脂培养基（ISP5）和马铃薯培养基（PDA）上生长良好，基生菌丝丰富，无气生菌丝。2株菌的最适生长温度为28℃，最适生长pH值7．0～7．5。综合2株菌的形态学、生理生化、细胞化学分类特征和基于16SrRNA基因序列的系统发育分析和DNA—DNA杂交结果，菌株45725和06—2230分别是多形态放线菌属的2个不同种。

A batch of actinobacterial strains were isolated from soil samples collected from medicinal plants rhizosphere. The strain 45725 showed strong activity of inhibiting the growth of Mycobacterium smegmatis and the isolate 06-2230strongly inhibited the growth of Pseudomonas aeruginosa. Both of the strains 45725 and 06-2230 showed good growth on the tested media, such as yeast-malt extract agar （ ISP2 ） , oatmeal agar （ ISP3 ） , inorganic salts and strach agar （ ISP4 ） , glycerol-asparagine agar （ ISP5 ） and potato exiract agar （PDA）. On these media, the substance hyphae of the two strains grew well without aeriel hyphae. The optimum growth temperature and the optimum growth pH range are is 28℃ and pH7.0-7.5, respectively. In view of morphology, physiological and biochemical characteristics, chemotaxonomic data, phylegentic analysis based on 16S rRNA gene sequence and DNA-DNA hybridiziton results, the studied strains belonged two different species of the genus Actinopolymorpha.