药用植物根系土壤可培养粘细菌的分离鉴定

Isolation and identification of cultivable myxobacteria in the rhizosphere soils of medicinal plants

摘要:

摘要:【目的】对药用植物根系土壤可培养粘细菌进行分离与鉴定，探讨药用植物根系土壤粘细菌资源多样性。【方法】采集华南植物园和南岭国家森林公园22种药用植物根系土，利用辅助菌诱导分离技术分离样品中可培养粘细菌;通过菌株显微形态和菌落形态观察，结合16S rDNA基因序列分析，确定分离粘细菌菌株的系统发育地位。【结果】分离获得50株粘细菌，分属于3个科，7个属，其中粘球菌属(Myxococcus)18株，珊瑚球菌属(Corallococcus)11株，孢囊杆菌属(Cystobacter) 7株，原囊菌属(Archangium)8株，标桩菌属(Stigmatella)1株，软骨霉状菌属(Chondromyces) 4株，匣状球菌属(Pyxidicoccus) 1株。粘球菌属和珊瑚球菌属分布最为广泛。【结论】研究发现药用植物根系土壤可培养粘细菌与土壤pH 和有机碳含量等环境因子有一定的相关性。粘细菌更适宜在有机质丰富、pH近中性的环境中生长;粘球菌属和珊瑚球菌属的菌株对pH适应性较强，而粘球菌属和孢囊杆菌属的菌株对土壤有机碳含量依赖性不强，在贫瘠土壤中仍有分布。本研究对后续粘细菌资源的开发和利用提供良好的实验材料和理论基础。

Abstract:

Abstract:［Objective］We isolated myxobacteria and explored their diversity from the rhizosphere soils of some medicinal plants．［Methods］ We used the helper bacteria baiting technique to isolate myxobacteria from the rhizosphere soils collected in South China Botanical Garden and Nanling National Forest Park． The myxobacteria were identified by morphological characteristics and 16S rDNA gene sequences analysis． ［Results］A total of 50 strains were isolated from 22 soil samples，which were identified into 7 genera，Myxococcus (18)，Corallococcus (11)，Cystobacter (7)，Archangium (8)，Stigmatella (1)，Chondromyces (4) and Pyxidicoccus (1)．The dominant genera were Myxococcus and Corallococcus． ［Conclusion］Environmental factors were associated with the diversity of myxobactria．Myxobacteria better adapt in high organic matter content and neutral pH environments．The strains of Myxococcus and Corallococcus had a good adaptability for different pH．Meanwhile，the dependence of the strains of Myxococcus and Cystobacter on organic carbon content was not too obvious，and they can also be found in the poor soils． Our findings provided an important scientific base for the development and utilization of myxobacteria resources．