Ghodsalavi Behnoushsadat, Svenningsen Nanna Bygvraa, Hao Xiuli, Olsson Stefan, Nicolaisen Mette Haubjerg, Al-Soud Waleed Abu, Sørensen Søren J, Nybroe Ole
Section for Microbial Ecology and Biotechnology, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark.
State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China.
PLoS One. 2017 Oct 27;12(10):e0187116. doi: 10.1371/journal.pone.0187116. eCollection 2017.
It is important to identify and recover bacteria associating with fungi under natural soil conditions to enable eco-physiological studies, and to facilitate the use of bacterial-fungal consortia in environmental biotechnology. We have developed a novel type of baiting microcosm, where fungal hyphae interact with bacteria under close-to-natural soil conditions; an advantage compared to model systems that determine fungal influences on bacterial communities in laboratory media. In the current approach, the hyphae are placed on a solid support, which enables the recovery of hyphae with associated bacteria in contrast to model systems that compare bulk soil and mycosphere soil. We used the baiting microcosm approach to determine, for the first time, the composition of the bacterial community associating in the soil with hyphae of the phosphate-solubilizer, Penicillium bilaii. By applying a cultivation-independent 16S rRNA gene-targeted amplicon sequencing approach, we found a hypha-associated bacterial community with low diversity compared to the bulk soil community and exhibiting massive dominance of Burkholderia OTUs. Burkholderia is known be abundant in soil environments affected by fungi, but the discovery of this massive dominance among bacteria firmly associating with hyphae in soil is novel and made possible by the current bait approach.
在自然土壤条件下识别和回收与真菌相关的细菌对于开展生态生理学研究以及促进细菌 - 真菌联合体在环境生物技术中的应用至关重要。我们开发了一种新型诱饵微观世界，其中真菌菌丝在接近自然的土壤条件下与细菌相互作用；与在实验室培养基中确定真菌对细菌群落影响的模型系统相比，这是一个优势。在当前方法中，菌丝放置在固体支持物上，这使得能够回收与菌丝相关的细菌，这与比较大量土壤和菌根际土壤的模型系统不同。我们首次使用诱饵微观世界方法来确定在土壤中与解磷真菌双孢青霉（Penicillium bilaii）菌丝相关的细菌群落组成。通过应用一种不依赖培养的靶向16S rRNA基因的扩增子测序方法，我们发现与大量土壤群落相比，与菌丝相关的细菌群落多样性较低，并且伯克霍尔德氏菌（Burkholderia）OTU占主导地位。伯克霍尔德氏菌在受真菌影响的土壤环境中已知含量丰富，但在土壤中与菌丝紧密相关的细菌中发现这种大量优势是新颖的，并且通过当前的诱饵方法得以实现。
