ED 01-Molecular Biology

Metabolic burden in Bacteria: tools and methods for Pseudomonas putida

ED - Mechanical Engineering

Systems Biotechnology

Molecular Microbiology

Further disciplines

Microbiology, Molecular Biology, Genetic Engineering

Planned project location:

Boltzmannstr. 15, 85748 Garching

Dr.

Katharina

Pflüger-Grau

k.pflueger-grau@tum.de

+49 89 28915765

The Professorship for Systems Biotechnology focuses on application of methods from systems biology to problems related to biotechnology. Apart from the improvement of the overall biotechnological processes, our main focus lies on the better understanding of the processes inside the cell. The Gram-negative bacteria Escherichia coli, Pseudomonas putida, and Halomonas elongata serve as model organisms due to their high potential in biotechnology. P. putida is an important workhorse for contemporary biotechnological applications, as it combines easy handling and fast growth with a low nutrient demand and an intrinsic resistance to metabolic and physiological stresses.

In an ongoing project in our laboratory, we aim to develop a comprehensive, system-level understanding of the physiology and metabolism of heterologous protein overproduction using P. putida as a host. The induction of protein overproduction in general leads to a switch in resource allocation from the normal cellular functions towards the additionally implemented task. These resources comprise not only the transcriptional and translational machinery, including RNA polymerase and ribosomes, but also chemical and redox energy. To face this new resource distribution, the metabolism as a whole has to adapt to ensure growth or at least the survival of the cells. If this fails, meaning that any of these resources becomes limiting, usually the growth rate decreases and heterologous production ceases. This phenomenon is referred to as `metabolic burden´. In the project the following questions are adressed: What is the cost for the production of a specific protein? Where are the bottlenecks during heterologous protein production? Can this information be generalized and eventually predicted? Our vision is to develop a toolbox that allows us to predict the optimal environment for a specific gene or, eventually, also for a small pathway in order to achieve the best performance possible.

You will work on a clearly defined part in that ongoing research project. From a technical point of view, the work will include cultivation of P. putida (and other Gram-negative bacteria), sophisticated molecular biology tools (cloning, deletion of genes, conjugation of plasmids, etc.), expression and analysis of fluorescent reporter genes and many more.

You will be part of an interdisciplinary group of scientists including biologists, engineers, chemists and mathematics. Furthermore, you have the possibility to join the weekly lab meeting with reports from the lab members of our group as well regular joint meetings of the chair of Bioprocess Engineering, the Bioseparation Engineering group, and our group.

40

2 years of bachelor studies completed

Laboratory experience: cultivation of bacteria; general knowledge of standard techniques in molecular biology (PCR, gel electrophoresis, cloning, etc.)