At the end of 2018, PhD students in the FocusLabs had the opportunity to apply for interdisciplinary mini-projects. Four projects were selected and started at the beginning of 2019.
Sonja Kubicki, Core Group Prof. Jaeger
Maximilian Schelden, Core Group Prof. Büchs
Jan Gebauer, Core Group Prof. Pietruszka
Robin Weihmann, Core Group Prof. Jaeger
The heterologous production of various high-value secondary metabolites in Pseudomonas putida is a main goal of the Bio² and CombiCom BioSC FocusLabs. Although this organism is used for example for heterologous rhamnolipid production, key questions such as the response to stressing metabolites remain unanswered.
Identifying traits that contribute to chemical stress tolerance along with the respective regulatory elements is the main objective of ResPuTra. We try to achieve this via RNA sequencing. The results may ultimately be applied to optimize production by knock-out or overexpression of identified genes and to establish biosensors for rhamnolipid production based on rhamnolipid inducible promoters.
Co-cultivation of bacteria with different physiological properties can offer several benefits for industrial biotechnology. However, cell growth and gene expression within synthetic microbial consortia need to be monitored and tightly controlled. The SynCom project therefore aims to develop a model co-cultivation platform for synthetic microbial consortia in which growth performance of individual Pseudomonas putida strains and selective target gene expression of different fluorescence reporters will be monitored online during co-cultivation. In the future, this system can be applied to the production of pharmacologically relevant secondary metabolites such as prodigiosin and its derivatives in the context of the CombiCom BioSC FocusLab.
Stefanie Brands, Core Group Prof. Schwaneberg
Liudmyla Goncharenko, Core Group Prof. Schwaneberg
Prodiginines are deep red bacterial secondary metabolites and a prominent example of a class of bioactive natural compounds. The prodigiosin synthase PigC catalyzes the final step of the bifurcated biosynthesis pathway of prodigiosin in Serratia marcescens. As a key enzyme in prodigiosin biosynthesis, its activity is an important bottleneck for prodiginine production. To date, the membrane-associated enzyme has not been purified with high purity and maintenance of activity. The ProdAnchor BioSC mini-project therefore envisions the establishment of an innovative purification method for PigC. The basic idea comprises immobilization of PigC on polypropylene surfaces using anchor peptides, which will be attached terminally to the PigC sequence. In ProdAnchor, technologies of two FocusLabs, CombiCom and greenRelease, will be merged for synergistic effect.
Mannosylerythritol lipids (MEL) are prominent biosurfactants with excellent properties. MEL can be efficiently produced with the smut fungus Pseudozyma aphidis, although larger quantities are formed only when oils are used as a substrate. When sugars are used instead, productivity and yield drop drastically. Here, a conflict arises because oils are food and should not be used as feedstock for bioprocesses. Thus, in the first part of this project, microbial oil will be produced sustainably from sugarbeet pulp using the oleaginous yeast Cryptococcus curvatus. The resulting oil will be isolated from cells using supercritical CO2 extraction and then used as a substrate for MEL production with P. aphidis in the second part of the project. MELOBEE is related to the FocusLab Bio².