药用植物内生放线菌的分离和生物学特性

Isolation and physiological characteristics of endophytic actinobacteria from medicinal plants

摘要:

摘要:【目的】探索药用植物内生环境可培养放线菌的分离、培养方法，总结药用植物内生放线菌的生物学特性，探讨其物种多样性，挖掘新的微生物资源。【方法】采用10 种分离培养基对37 个新鲜的药用植物样品进行内生放线菌的分离;通过比较，选择适合植物内生放线菌生长的培养条件;根据菌落形态和细胞特征观察结果，选择其中174 株菌测定16S rRNA 基因序列，分析药用植物内生放线菌的多样性;应用Biolog GEN III 微孔培养、API 50CH 以及API ZYM 试剂条测试27 株代表菌株的生理生化特性。【结果】分离得到940株植物内生菌，分属于47 个属，30 个科，其中放线菌600 余株，分属于34 个属，共发现潜在的新分类单元有7 个;本研究中药用植物内生放线菌的培养条件是:PYG 培养基、pH7. 2、28℃ － 32℃;菌株间的生物学特性的差异与菌株系统进化关系呈正相关关系;不同环境植物的内生菌菌株的生物学特性差异较大，相同环境的不 同植物内生菌的生物学特性差异较小。【结论】药用植物内生放线菌物种丰富多样;药用植物内生放线菌在唯一碳源利用、发酵碳源产酸及酶学活性等生理生化特性方面没有表现出和宿主植物的直接相关性，而是呈现出和宿主植物的地理分布有一定的相关性。

Abstract:

Abstract:［Objective］To isolate，incubate and characterize cultivable endophytic antinobacteria from medicinal plants，and analyze the diversity of the endophytic antinobacteria，then explore the novel microbial resources．［Methods］Ten media were used to isolate endophytic antinobacteria from 37 fresh medicinal plant tissue samples． The optimal cultivation conditions for endophytic antinobacteria were determined by comparison． Based on the morphology of the colonies and cells of the new isolates，we chose174 isolates to analyze their 16S rRNA gene sequences and the diversity of the medicinal plant endophytic antinobacteria． The physiological characteristics of 27 representative strains were studied using Biolog GEN III MicroPlates，API 50CH and API ZYM kits．［Results］In total 940 endophytics affiliated to 47 genera of 30 families were isolated，among which more than 600 actinobacteria belonged to 34 genera and 7 unknown taxa． Good growth of the endophytic antinobacteria on PYG ( peptone-yeast-glycerol) medium with pH 7.2 at 28－32℃ was observed．Physiological characteristics differences of these isolates related to their phylogenetic relationships． Greater differences were shown among the strains from the same host plants than those from different plants grown in the same area．［Conclusion］There are great diverse endophytic actinobacteria inside the medicinal plants． No direct relationship of the endophytic actinobacteria from medicinal plants with the host plants in the sole carbon source utilization，fermentation of carbon sources to produce acid and the enzyme activities was found，while it seemed that the physiological characteristics of the isolates related to the geographical distribution of their host．