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, P.O. Box 1129, 85764, Neuherberg, Germany.
Microb Ecol. 2007 Jul;54(1):151-60. doi: 10.1007/s00248-006-9183-0. Epub 2007 Mar 16.
Ozone is considered as the main factor in air pollution related to a decline of forest in North America and Europe. In the present study, the effect of changed litter quality, due to ozone stress to trees, on the microbial communities colonizing the subsequent litter was investigated. Litter bag technique using beech and spruce litter from ozone-stressed and control trees, was combined with 16S and 18S rRNA-based fingerprinting methods and cloning to characterize phylogenetic diversity. Litter bags were incubated for 2 and 8 weeks in a beech-spruce mixed forest. Differences between the structure of microbial communities colonizing control and ozone-exposed litter were evident by fingerprints of 16S and 18S rRNA RT-PCR products. RT-PCR products, from litter degraded for 8 weeks, were cloned to identify the bacterial and fungal groups. Clones similar to members of Actinobacteria dominated the bacterial libraries, whereas effects of changed litter quality were mainly observed for the Proteobacteria. Fungal libraries were dominated by clones similar to Ascomycota members. Reduced proportion of clones similar to Basidiomycota and Zygomycota in library from ozone-stressed spruce trees and Chytridiomycota from ozone-stressed beech trees was observed when compared to their control counterparts. As hypothesized, changed litter quality due to elevated O3 did influence the structure of litter-colonizing microbial communities. However, these differences were not as pronounced as those between the two plant species.
臭氧被认为是与北美和欧洲森林衰退相关的空气污染的主要因素。在本研究中，调查了由于树木受到臭氧胁迫而导致的凋落物质量变化对定殖于后续凋落物上的微生物群落的影响。使用来自受臭氧胁迫树木和对照树木的山毛榉和云杉凋落物的凋落物袋技术，与基于16S和18S rRNA的指纹图谱方法及克隆相结合，以表征系统发育多样性。凋落物袋在山毛榉-云杉混交林中培养2周和8周。通过16S和18S rRNA RT-PCR产物的指纹图谱可以明显看出定殖于对照凋落物和暴露于臭氧的凋落物上的微生物群落结构之间的差异。对降解8周的凋落物的RT-PCR产物进行克隆，以鉴定细菌和真菌类群。与放线菌成员相似的克隆在细菌文库中占主导地位，而对于变形菌门，主要观察到了凋落物质量变化的影响。真菌文库中以与子囊菌门成员相似的克隆为主。与对照相比，在受臭氧胁迫的云杉树的文库中，与担子菌门和接合菌门相似的克隆比例降低，在受臭氧胁迫的山毛榉树的文库中，与壶菌门相似的克隆比例降低。正如所假设的，由于O3浓度升高导致的凋落物质量变化确实影响了定殖于凋落物上的微生物群落结构。然而，这些差异并不像两种植物物种之间的差异那么明显。
