Bettina Siebers

Cyanobacteria are the only prokaryotes performing oxygenic photosynthesis. Theyhad and have tremendous influence on the biogeochemical cycles on Earth. Recently,cyanobacteria are increasingly investigated as cell factories for a sustainableeconomy. Despite their global, environmental and rising economic importance, ourknowledge on the regulation of their primary metabolism is fragmented.Cyanobacteria switch between photoautotrophic and heterotrophic modes ofmetabolism during day/night cycles or ...

The goal of the project is to establish a new biotechnological platform for the production of hydroxy-amino acids, since the current production of these important building blocks is very expensive. Enzyme engineering, systems biotechnology and metabolic engineering will be used in a synthetic biology approach.

Background- Thermophilic organisms are composed of both bacterial and archaeal species. The enzymes isolated from these species and from other extreme habitats are more robust to temperature, organic solvents and proteolysis. They often have unique substrate specificities and originate from novel metabolic pathways. Thermophiles as well as their stable enzymes (‘thermozymes’) are receiving increased attention for biotechnological applications.

The proposed project will establish thermophilic in ...

Silicon cell model for the central carbohydrate metabolism of the archaeon Sulfolobus solfataricus under temperature variation

Within the e:Bio - Innovationswettbewerb Systembiologie (Federal Ministry of Education and Research (BMBF)), the SulfoSYSBIOTECH consortium (10 partners), aim to unravel the complexity and regulation of the carbon metabolic network of the thermoacidophilic archaeon Sulfolobus solfataricus (optimal growth at 80°C and pH 3) in order to provide new catalysts ‘extremozymes’ for utilization in White Biotechnology.

Based on the available S. solfataricus genome scale metabolic model (Ulas et al., 2012) ...

Present in many industrial effluents and as intermediate of lignin degradation, phenol is a widespread pollutant causing serious environmental problems, due to its toxicity to animals and humans. Removal of phenol from the environment by bacteria has been studied extensively over the past decades, but only little is known about phenol biodegradation in hostile environments. We combined metabolomics and transcriptomics together with metabolic modelling to elucidate the organism’s response to growth ...

Integrated systems biology approach including transcriptome, metabolome, proteome analyses and modelling to elucidate amino acid degradation in S. solfataricus P2.

Integrated systems biology approach including transcriptome, metabolome, biochemistry, proteome analyses and modelling to elucidate the catabolic pathway for L-fucose in S. solfataricus P2.

To investigate phenol degradation in Saccharolobus solfataricus transcriptome and metabolome analyses were performed with cells grown on phenol as sole carbon source. Cells grown on D-glucose served as reference. Metabolic modelling was used to compare efficiency of phenol utilization in terms of oxygen demand and energy yield with the reference condition.

To investigate amino acid degradation pathways in Sulfolobus solfataricus transcriptome, proteome and metabolome analyses were performed on cells grown on caseinhydrolysate as carbon source. Cells grown with glucose served as reference condition. Metabolic modelling was used to compare the efficiency of different degradation routes.

Activity assays in cell free extracts of S. solfataricus grown on either L-fucose or D-glucose and activity assays with recombinant proteins