Stefan Pfeiffer

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Ninety-seven strains of budding bacteria originating from various aquatic habitats and morphologically resembling planctomycetes were investigated taxonomically. Taxonomic differentiation was based on DNA-DNA hybridization, physiological properties and chemotaxonomic tests. Nineteen hybridization groups, containing 79 of the tested strains, were(More)
A Gram-reaction-negative, yellow-pigmented strain, designated EX36(T), was characterized using a polyphasic approach comprising phylogenetic, morphological and genotypic analyses. The endophytic strain was isolated from Zn/Cd-accumulating Salix caprea in Arnoldstein, Austria. Analysis of the 16S rRNA gene demonstrated that the novel strain is most closely(More)
Adelgids (Insecta: Hemiptera: Adelgidae) are known as severe pests of various conifers in North America, Canada, Europe and Asia. Here, we present the first molecular identification of bacteriocyte-associated symbionts in these plant sap-sucking insects. Three geographically distant populations of members of the Adelges nordmannianae/piceae complex,(More)
Quantitative PCR (qPCR) and community fingerprinting methods, such as the Terminal Restriction Fragment Length Polymorphism (T-RFLP) analysis,are well-suited techniques for the examination of microbial community structures. The use of phylum and class-specific primers can provide enhanced sensitivity and phylogenetic resolution as compared with(More)
Different regions of the bacterial 16S rRNA gene evolve at different evolutionary rates. The scientific outcome of short read sequencing studies therefore alters with the gene region sequenced. We wanted to gain insight in the impact of primer choice on the outcome of short read sequencing efforts. All the unknowns associated with sequencing data, i.e.(More)
Usually, safety and robustness are considered as the most important issues when designing and developing smart and wireless eHealth systems for ambient support of patients and physicians. However, information security is an indispensable design criterion due to the sensitive and critical nature of aggregated information from eHealth applications. Therefore,(More)
Providing network security is one of the most important tasks in today’s Internet. Unfortunately, many users are not able to protect themselves and their networks. Therefore, we present a novel security concept to protect users by providing security measures at the Internet Service Provider (ISP) level. Already now, ISP are using different security(More)
The rhizosphere hosts a rich microflora supporting plant nutrition and health. We examined bacterial rhizosphere microbiota of Solanum tuberosum grown in its center of origin, the Central Andean Highlands, at different vegetation stages and sites at altitudes ranging from 3245 to 4070 m.a.s.l., differing in soil characteristics, climate and the agricultural(More)
What visions of technologies such as the Internet of Things (IoT), Pervasive Computing (PC) or Ambient Intelligence (AI) have in common is that they employ a very high amount of critically resource-constrained devices. This of course raises a whole set of new security challenges. Instead of proposing another middleware for IoT, PC or AI, and presenting a(More)
Developing a security concept feasible for a large number of cooperating embedded devices is crucial for the practical relevance of visions such as the Internet of Things, Ambient Assisted Living or Pervasive Computing. However, designing these concepts in conjunction with new technologies usually is more expensive. Thus, new technologies often rely on(More)