大兴安岭地区粘细菌资源的多样性及其生物活性

Diversity and bioactivities of myxobacteria in Daxing’an Mountains

摘要:

【背景】粘细菌是一类具有社会性行为的高等原核生物，其代谢产物具有丰富、多样、新颖的生物活性，是筛选天然药物的良好资源，具有很大的研究开发应用价值。【目的】分析大兴安岭地区粘细菌资源的多样性；分离纯化可培养的粘细菌，分析其抗菌活性并从中筛选对马铃薯晚疫病菌具有拮抗作用的菌株。【方法】通过变性梯度凝胶电泳(DGGE)技术对从大兴安岭地区采集的15个土样中粘细菌资源的多样性进行分析，利用兔粪诱导、大肠杆菌划线诱导和滤纸诱导3种方法从土样中分离可培养的粘细菌，结合形态观察、生理生化特征和16S rRNA基因序列分析确定这些菌株的分类地位，通过平板对峙法对其进行抗菌活性分析。【结果】DGGE的分析结果显示，15个土样中共鉴定到13个属的粘细菌，基本覆盖了大部分已知的粘细菌种属以及部分未分类的粘细菌，表现出了丰富的多样性。共分离得到88株菌，从中得到22株纯菌，经鉴定属于2个属(粘球菌属与珊瑚球菌属) 8个种(黄色粘球菌、橙色粘球菌、变绿粘球菌、珊瑚粘球菌、具枝粘球菌、大孢珊瑚球菌、弱小珊瑚球菌和珊瑚状珊瑚球菌)。抗菌结果显示：22株纯菌均表现出可以对一种甚至多种指示菌产生抗性，其中19株抑制大肠杆菌的生长，14株抑制马铃薯晚疫病菌的生长，8株抑制金黄色葡萄球菌的生长，13株抑制酿酒酵母菌的生长，7株抑制枯草芽孢杆菌的生长。【结论】内蒙古大兴安岭地区蕴藏着丰富的粘细菌资源，粘球菌属及珊瑚球菌属可能为该地区粘细菌菌群中的优势菌。分离纯化出的粘细菌菌株均表现出抑制一种甚至多种指示菌生长的活性，其中64%的纯菌对马铃薯晚疫病菌产生抗性，具有进一步研究的潜在价值。

Abstract:

[Background] Myxobacteria are a group of higher prokaryotes with social behavior. They have great research value in screening natural drugs because their metabolites have rich, diverse and novel biological activities. [Objective] We studied the diversity of myxobacteria in Daxing’an Mountains of Inner Mongolia, and isolated and purified the culturable myxobacteria, and studied their antimicrobial activities and screened strains against Phytophthora infestans. [Methods] The diversity of myxobacteria was studied by PCR-denaturing gradient gel electrophoresis (DGGE). Culturable myxobacteria were isolated from 15 soil samples collected from Daxing’an Mountains by rabbit dung pellets inducing method, Escherichia coli inducing method, and filter paper inducing method. The purified strains were identified by morphological observation, physiological and biochemical characteristics, and the 16S rRNA gene sequence analysis. Then, the antimicrobial activities of the strains were determined by plate confrontation method. [Results] The results of DGGE showed that 13 genera of myxobacteria were identified from 15 soil samples, covering most of the known genera of myxobacteria and some of the unclassified myxobacteria. 88 strains were isolated in this study and 22 of them were purified. The purified strains belonged to two genera, Myxococcus and Corallococcus, and 8 species, Myxococcus xanthus, Myxococcus flavescens, Myxococcus virescens, Myxococcus coralloides, Myxococcus stipitatus, Corallococcus macrosporus, Corallococcus exiguous, Corallococcus coralloides. All of the purified myxobacterial strains exhibited one or more kinds of antimicrobial activities. 19 strains had the activity against E. coli. 14 strains had the activity against Phytophthora infestans. Eight strains showed the activity against Staphylococcus aureus. 13 strains had the activity against Saccharomyces cerevisiae. Seven strains showed the activity against Bacillus subtilis. [Conclusion] Myxobacterial resource in Daxing’an Mountains of Inner Mongolia is rich. Myxococcus and Corallococcus could be the dominant populations of myxobacterial community in this region. The purified myxobacterial strains exhibited one or more kinds of antimicrobial activities and 64% of them have the activity against Phytophthora infestans, which has the potential value for further research in the future.