<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>13</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Meola, M</style></author><author><style face="normal" font="default" size="100%">Lazzaro, A</style></author><author><style face="normal" font="default" size="100%">Zeyer, J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Presence and diversity of bacterial functional groups in two different glacier forefields</style></title><short-title><style face="normal" font="default" size="100%">Presence and diversity of bacterial functional groups in two different glacier forefields</style></short-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">16S rRNA</style></keyword><keyword><style  face="normal" font="default" size="100%">bacterial diversity</style></keyword><keyword><style  face="normal" font="default" size="100%">functional genes</style></keyword><keyword><style  face="normal" font="default" size="100%">glacier forefields</style></keyword><keyword><style  face="normal" font="default" size="100%">T-RFLP</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">27.10.2011</style></date></pub-dates></dates><pub-location><style face="normal" font="default" size="100%">Microbial Diversity 2011 Conference, Milan, Italy,</style></pub-location><abstract><style face="normal" font="default" size="100%">Microorganisms in glacier forefields are exposed to extreme environmental conditions. For example, there are strong fluctuations in temperature during the snow free season and in winter they are efficiently insulated by the snow cover. Moreover, recently deglaciated glacier forefields are oligotrophic causing challenging conditions for the autochtonous microbial community. Although glacier forefields are generally similar at a first glance, microbial community composition can vary substantially between different glacier forefields with different bedrock geology (Lazzaro et al., 2009). Previous results suggest that autochtonous microbial communities in such environments may display a certain level of local adaptation. Microbial community structures might be strongly affected by one or several environmental factors, ranging from soil characteristics (e.g. nature of the bedrock, pH, soil moisture, soluble ions) to site-related characteristics (e.g. climate). 
The debate on the role of each factor determining the presence and abundance of certain microbial groups is still open. Moreover, it is of vital importance to understand how locally adapted microbial groups may respond to changing environmental factors, in terms of resistance and resilience (ecological stability).
In this project, we aim at understanding the issues of ecological stability of glacier forefield bacterial communities to changing environmental factors. Due to their relatively simple structure, glacier forefield communities can easily be monitored. Moreover, the absence of plants characterizing these young environments facilitates the studies. In this project we focus on the glacier forefields of Griessen (Canton Obwalden, calcareous bedrock), and Tiefen, (Canton Uri, siliceous bedrock) located in the Swiss Alps at an altitude of about 2500 m.a.s.l.
Preliminary studies consist of three approaches to assess bacterial diversity in these glacier forefields. 
First, Terminal-Restriction Fragment Length Polymorphism (T-RFLP) of the 16S rRNA gene has been performed. T-RFLP profiles on 16S rRNA showed that the bacterial communities of the two different glacier forefields are different in composition and diversity. In fact, in Tiefen we observe a higher diversity (average 117 T-RFLP peaks) than in Griessen (50 T-RFLP peaks).
Furthermore, presence and abundance of specific groups has been determined by PCR-based analysis with group-specific 16S primers. The results revealed a strong presence of α-proteobacteria in Tiefen, but an almost complete absence in Griessen. 
Finally, PCR of relevant functional genes were analyzed (e.g. nosZ, nirK, nirS, nifH, chiA, apr, amoB, amoA) targeting important microbial processes that characterize young glacier forefields (Brankatschk et al., 2010). The results revealed the presence of the functional genes nosZ, nirK, nirS, chiA and amoB in samples from both glacier forefields. However, nifH, amoA and apr were not detected.
The observed differences in bacterial composition and relative abundance of functional groups will be further assessed by qPCR. 
In addition, we present an outlook of planned field and lab-experiments to test the role of selected environmental factors (e.g. soil moisture) on the microbial community structure and activity.
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