Stephan Gantner

Rheinische Akademie Köln gGmbH · Höhere Berufsfachschule für Technik (HBT), higher vocational education and training

We examined the bacterial endophyte–enriched root-associated microbiome within rice (Oryza sativa) 55 days after growth in soil with and without urea fertilizer and/or biofertilization with a growth-promotive bacterial strain (Rhizobium leguminosarum bv. trifolii E11). After treatment to deplete rhizosphere/rhizoplane communities, washed roots were...

Planktonic bacterial community dynamics over short timescales can be of great importance for food webs and ecosystem functioning but are rarely described when microbial community and composition are assessed. To study the significance of such dynamics we sampled the surface water at the deepest point of a mesotrophic lake (Lake Erken, Sweden) every...

Laboratory assistants in biology and medicine play a central role in the operation of laboratories in hospitals, research institutes, and industries. Their daily work routine is characterized by dealing with molecular structures/chemical substances (i.e. biochemistry) as well as cell cultures (i.e. cell biology). In both these fields of biochemistr...

Observations of distributions of microorganisms and their differences in community composition across habitats provide evidence of biogeographical patterns. However, little is known about the processes controlling transfers across habitat gradients. By analysing the overall microbial community composition (bacteria, fungi, archaea) across a terrest...

Evolution is a central topic in biology teacher education and school biology lessons. However, national and international studies have shown that not only ordinary people but also biology teachers have difficulties to understand the theory of evolution. Based on research in content-related professional knowledge, the present study aimed developing...

We performed computer-assisted microscopy at single-cell resolution to measure the in situ spatial scale of N-acylhomoserine lactone (AHL)-mediated cell-to-cell communication of Pseudomonas putida reporter strains colonized on tomato and wheat root surfaces. In situ image analysis indicated that the effective “calling distance” separating activated...

The shorter reads generated by high-throughput sequencing has led to a focus on either the ITS1 or ITS2 sublocus in fungal diversity analyses. Our study aimed to determine how making this choice would influence the datasets obtained and our vision of environmental fungal diversity. DNA was extracted from different environmental samples (water, sedi...

Metacommunity theory has advanced understanding of how spatial dynamics and local interactions shape community structure and biodiversity. Here, we review empirical approaches to metacommunities, both observational and experimental, pertaining to how well they relate to and test theoretical metacommunity paradigms and how well they capture the real...

Next generation sequencing technologies for in depth analyses of complex microbial communities rely on rational primer design based on up-to-date reference databases. Most of the 16S rRNA-gene based analyses of environmental Archaea community composition use PCR primers developed from small data sets several years ago, making an update long overdue...

The rhizosphere habitat includes living plant roots and closely associated soil where deposited exudates stimulate microbial activities that significantly influence plant health and disease, and therefore are important for terrestrial ecosystems and agriculture. This article highlights the current understanding of the rhizosphere and how various re...

Favorable cropping systems that promote residue retention would normally lead to increased soil carbon storage. Experiments were conducted to test the hypothesis that soil carbon of different fallow management practices influences more the microbial biomass carbon and activity than the microbial community structure. Also, the distribution of the ma...

It is well known that the bacterial diversity in soil habitats is much greater compared to the artificial cultivation techniques (Torsvik et al. 1996; Chatzinotas et al. 1998). It is generally accepted that only a combination of methods including cultivation and several cultivation-independent techniques is able to provide a more representative pic...

N-acyl-L-homoserine lactone (AHL) signal molecules are utilized by Gram-negative bacteria to monitor their population density (quorum sensing) and to regulate gene expression in a density-dependent manner. We show that Serratia liquefaciens MG1 and Pseudomonas putida IsoF colonize tomato roots, produce AHL in the rhizosphere and increase systemic r...

We used computer-assisted microscopy at single cell resolution to quantify the in situ spatial scale of N-acylhomoserine lactone (AHL)-mediated cell-to-cell communication of Pseudomonas putida colonized on tomato and wheat root surfaces. The results of this in situ quantification study on close-to-natural surfaces challenge the conventional view of...

N-acyl-L-homoserine lactone (AHL) signal molecules are utilized by Gram-negative bacteria to monitor their population density (quorum sensing) and to regulate gene expression in a density-dependent manner. We show that Serratia liquefaciens MG1 and Pseudomonas putida IsoF colonize tomato roots, produce AHL in the rhizosphere and increase systemic r...

Der Pflanzenbewuchs und die durchwurzelte Bodenschicht nehmen eine zentrale Stellung in terrestrischen Ökosystemen ein. Die Bedeutung der im Wurzel-Boden-Kontaktraum ablaufenden komplexen Prozesse für die Pflanzen- und Bodenentwicklung wurde lange Zeit nicht ausreichend erkannt. Diese grundlegenden Prozesse sind inzwischen als so genannte "Hidden H...

Gram-negative Bakterien verfügen über ein eigenes Regulationssystem, das sie zur Interaktion befähigt (Eberl 1999). Diese Art der Zell-Zell-Kommunikation erfolgt über Signalmoleküle vom Typ N-Acyl-L-Homoserin-Lacton (AHL), welche erst ab Erreichen eines bestimmten Schwellenwertes eine zellspezifische Reaktion auslösen (Quorum sensing) z.B. die Prod...

Given that a large proportion of the bacteria colonizing the roots of plants is capable of producingN-acyl-l-homoserine lactone (AHL) molecules, it appears likely that these bacterial pheromones may serve as signals for communication between cells of different species. In this study, we have developed and characterized novel Gfp-based monitor strai...

N-Acylhomoserinlactones (AHL) are signalling molecules in gram-negative bacteria, which regulate, in a cell density dependent way, important interactive functions. This phenomenon is known as quorum-sensing. This work characterised the microbial ecology of the autoinducer (AHL) producing bacteria Serratia liquefaciens MG1 and Pseudomonas putida Iso...