Aneja Manish Kumar, Sharma Shilpi, Fleischmann Frank, Stich Susanne, Heller Werner, Bahnweg Günther, Munch Jean Charles, Schloter Michael
Institute of Soil Ecology, GSF-National Research Center for Environment and Health, PO Box 1129, D-85764, Neuherberg, Germany.
Microb Ecol. 2006 Jul;52(1):127-35. doi: 10.1007/s00248-006-9006-3. Epub 2006 May 12.
The present study was conducted to investigate the effect of decomposition site and plant litter species on the colonizing microbial communities. For this, litter bag technique using beech and spruce litter was combined with RNA-based fingerprinting and cloning. Litter bags were incubated for 2 and 8 weeks in the Ah horizon of beech and beech-spruce mixed forest sites. Although sugars and starch were rapidly lost, lignin content increased by more than 40% for beech and more than doubled for spruce litter at both soil sites at the end of the experiment. Denaturing gradient gel electrophoresis analysis of 16S and 18S rRNA RT-PCR products was used for screening of differences between bacterial and fungal communities colonizing the two litter types. Development of the microbial community over time was observed to be specific for each litter type and decomposition site. RT-PCR products from both litter types incubated in beech-spruce mixed forest site were also cloned to identify the bacterial and fungal colonizers. The 16S rRNA clone libraries of beech litter were dominated by gamma-proteobacterial members, whereas spruce libraries were mainly composed of alpha-, beta-, and gamma-proteobacterial members. Ascomycota members dominated the 18S rRNA clone libraries. Clones similar to Zygomycota were absent from spruce, whereas those similar to Basidiomycota and Glomeromycota were absent from beech libraries. Selective effects of litter quality were observed after 8 weeks. The study provides an insight into the bacterial and fungal communities colonizing beech and spruce litter, and the importance of litter quality and decomposition site as key factors in their development and succession.
本研究旨在调查分解地点和植物凋落物种类对定殖微生物群落的影响。为此，将使用山毛榉和云杉凋落物的凋落袋技术与基于RNA的指纹图谱和克隆技术相结合。凋落袋在山毛榉和山毛榉 - 云杉混交林的Ah层中分别培养2周和8周。尽管糖类和淀粉迅速流失，但在实验结束时，两个土壤地点的山毛榉凋落物木质素含量增加了40%以上，云杉凋落物的木质素含量增加了一倍多。利用16S和18S rRNA RT-PCR产物的变性梯度凝胶电泳分析来筛选定殖在两种凋落物类型上的细菌和真菌群落之间的差异。观察到微生物群落随时间的发展对于每种凋落物类型和分解地点都是特定的。在山毛榉 - 云杉混交林中培养的两种凋落物类型的RT-PCR产物也进行了克隆，以鉴定细菌和真菌定殖者。山毛榉凋落物的16S rRNA克隆文库以γ-变形菌纲成员为主，而云杉文库主要由α-、β-和γ-变形菌纲成员组成。子囊菌门成员主导了18S rRNA克隆文库。云杉中没有与接合菌门相似的克隆，而山毛榉文库中没有与担子菌门和球囊菌门相似的克隆。8周后观察到凋落物质量的选择效应。该研究深入了解了定殖在山毛榉和云杉凋落物上的细菌和真菌群落，以及凋落物质量和分解地点作为其发展和演替关键因素的重要性。
