| 摘要: |
| 粘细菌是一类分布广泛的捕食性细菌，能够产生种类多样、结构新颖、作用机制独特的天然活性物质。但是粘细菌分离纯化困难且耗时，导致其资源匮乏，这已成为粘细菌开发利用的重要瓶颈之一。基于辅助菌的分离方法是当前获得粘细菌资源的重要方法，然而辅助菌多为大肠杆菌（Escherichia coli）等革兰氏阴性菌。为了获得新的辅助菌和粘细菌资源，本研究基于土壤细菌16S rRNA基因高通量测序数据构建细菌共现网络（bacterial co-occurrence network），发现粘细菌-细菌子网络中有27%的连接节点为放线菌。因此，本研究选择革兰氏阳性菌球形节杆菌（Arthrobacter globiformis） GDMCC 1.1730作为辅助菌，并在捕食培养基上验证其捕食活性。结果表明该辅助菌能够被所有参与测试的粘细菌（12个物种）所捕食。以GDMCC 1.1730作为辅助菌进行粘细菌的分离，共诱导出11种粘细菌子实体，且包括一种仅由GDMCC 1.1730诱导而大肠杆菌未能诱导出的子实体。本研究基于细菌共现网络和捕食活性验证，提供了一株革兰氏阳性菌作为新的粘细菌辅助菌，该辅助菌能够诱导出土壤中的多种粘细菌子实体，为根据细菌共现网络获取未/难培养微生物资源提供了新的证据。 |
| 关键词: 细菌共现网络 捕食 辅助菌 粘细菌 子实体 |
| DOI：10.14188/j.ajsh.2020.05.007 |
| 分类号:Q939.11 |
| 基金项目:国家自然科学基金（31900084）；广东省科技计划项目（2019B030316010） |
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| Isolation of soil myxobacteria based on bacterial co-occurrence network |
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ZHOU Yang1, YI Shuoxing1,2, ZHANG Xianjiao1, YAO Qing3, ZHU Honghui1
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1.State Key Laboratory of Applied Microbiology Southern China/Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application/Guangdong Microbial Culture Collection Center （GDMCC）， Guangdong Institute of Microbiology， Guangzhou 510070， Guangdong， China;2.College of Agriculture， South China Agricultural University， Guangzhou 510642， Guangdong， China;3.College of Horticulture， South China Agricultural University， Guangzhou 510642， Guangdong， China
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| Abstract: |
| Myxobacteria are a kind of widely distributed predatory bacteria，which can produce natural active substances with diverse species， novel structure and unique mechanism of action. However， the screening of myxobacteria has been hampered because of the difficult isolation and purification and time-consuming. The prey-induction isolation is the traditional method for myxobacteria screening， and Escherichia coli is frequently selected as the prey strain. To obtain new prey bacteria and increase the diversity of myxobacteria， this study constructed bacterial co-occurrence network based on 16S rRNA gene sequencing， and we found 27% links of myxobacteria-bacteria in subnetwork were with Actinobacteria. An actinobacterial strain Arthrobacter globiformis GDMCC 1.1730 was selected as prey to test the predatory abilities of different myxobacterial species. The results showed that all the selected myxobacterial strains were capable to prey upon this strain. Therefore， we used GDMCC 1.1730 as prey to isolate myxobacteria from soil samples， and baited 11 types of myxobacteria fruiting bodies with one specifically induced by GDMCC 1.1730 but not by E. coli. Based on soil bacterial co-occurrence network and the confirmation of predatory ability， this study reports a new Gram positive baiting strain for myxobacterial isolation， which provides new evidence for the effectiveness of using network-directed isolation to obtain uncultivated microbial resources. |
| Key words: bacterial co-occurrence network predation helper strain myxobacterium fruiting body |
