Microbiology / Molecular Biology

 

Transducing particles

Keep different bacterial strains in the stationary phase and observe hopefully the formation of particles.
These particles need to be tested for transducing capabilities, described via ultrastructual approach, followed by extraction of DNA, sequencing and determination of size of genome. Evolution of the genome of transducing particles of various generations should be investigated to understand whether the genetic information within the produced particles increases with the number of induced transduction steps.

This is actually examined by Lisa Stöger within her diploma thesis.

 

Virology / Molecular Biology

 

RNA–viruses in sediments and water columns of Danubian backwater systems

Determination of RNA viruses in sediments and water by microbiological und molecular biological techniques.

This is actually examined by Armin Lökher within his diploma thesis.

 

Microbiology / Virology / Molecular Biology

 

Is the microbial/viral loop a functional component in the human gut

Fecal samples from various gut regions of humans have to be investigated. Those samples should be analysed under the epifluorescence microscope for a) number and morphotypes of bacteria b) protozoans c) viruses and the viral loop within the gut will be analyzed by molecularbiological methods.

This will be investigated by Melanie Kappelmann within her diploma thesis (starts March 2010).

 

Microbiology

 

Most abundant species of bacteria in an ecosystem

Dilution by extinction ( 3 seasons at most), Culture techniques, try different substrates, if detectable and culturable then encourage the construction of probes or specific markers to cross check the experimental findings on in situ samples.

 

Natural mortality of bacteria

Determination in both sediments and the water column (3 seasons at most). Cultivated strains to be treated with life/deadth dyes, detrmination for various strains and in the following with mixed populations.
Specific question for sediments: Since bacterial control is low, as observed for HNF and viruses, the natural  mortality must be high or else be exported from the system.

 

Carbon conversion efficiency of mixed bacterial populations

A prerequisite for this investigation is the availability of a DOC analyser and the goal of the research is to provide realistic conversion factors for bacteria from the water column and the sediments of danubian backwater systems in order to correct already established carbon budgets for some of these systems. If possible, the investigations should be extended to the marine environment.

 

Virology

 

Viral abundance and decay in seagrass ecosystems

First step is the determination of basic data on the distribution of viruses in the water column from shallow to deep in several sampling sites along a transect from the coast to the edge of the seagrass system. In a second step, decay experiments need to be set up to estimate production of viruses and impact on BSP. The work can be extended into the sediments of the system whereby one should distinguish between wrack bed sediments and the sediment of the meadow.