The Group of Molecular Microscopy and Biotechnology

We are an interdisciplinary group consisting of both biologists and physicists. Our research activities relate mainly to the fields of Metabolic Engineering and Molecular Microscopy.

Metabolic Engineering

Our research activities are focused on developing the yeast Saccharomyces cerevisiae into an efficient producer (cell factory) of various chemicals and fuels by using a metabolic engineering approach. We have a long standing history of research in connection to optimization of bioethanol production. In more recent years we have also included butanol has an alternative biofuel that has many advantages compared to ethanol. S. cerevisiae is not a natural producer of butanol but by identification and insertion of suitable genes followed by protein engineering and careful selection of process conditions a novel efficient butanol forming organism/process will be developed. A similar approach has been used to transform S. cerevisiae into an ethylene producing organism. The aim of this project is to develop a sustainable process using renewable substrates for production of polyethylene that nowadays rely on finite fossil resources.

In order to be successful in our metabolic engineering projects we also focus on exploring the mechanisms for regulation/control of various metabolic pathways in the cell. Special attention has been directed towards the role of energy metabolism and the importance of adenine nucleotide levels but also redox metabolism is a field of interest.

The field of metabolic engineering in most cases relies on changing/adding the expression of proteins/genes in the host organism. To achieve proper expression and/or localization of the targetted protein it is necessary to understand the different layers of gene regulation involved. One project related to basic research into this area concerns the role(s) of, and regulatory mechanisms acting via the 3' untranslated region, using yeast as a model organism.

Molecular Microscopy

Generations of scientists within the bio- and material sciences have created microscopy images based on the light absorption, scattering, refraction and polarization properties of their samples. In our strive to visualize the ”invisible”, the requirements of resolution and contrast have the last decade changed radically: we want to follow biochemical processes on a molecular level with high temporal resolution in living cells. This stimulates us to seek beyond the traditional techniques utilizing transmitted and reflected light, which has induced the development of a series of sophisticated microscopy methods based on multi-photon processes where the conventional light sources are replaced by technically advanced laser systems. Non-centrosymmetric bio-polymers such as collagen fibers can be visualized by Second Harmonic Generation (SHG), membranous structures by Third Harmonic Generation (THG) and the specific vibrational properties of bio-molecules by Coherent Anti-Stokes Raman Scattering (CARS) – all without interference by any labeling molecules or sample preparation procedures. Thus, the distribution of macromolecules in cellular systems can be studied in full 3-dimensions at sub-micron resolution (~300 nm) under physically and biologically natural conditions. An overview is given of the necessary technology behind multi-photon microscopy, as well as some examples from the research conducted in the Group of Molecular Microscopy and Biotechnology at Chalmers University of Technology. CARS/SHG microscopy images of the dynamic formation of lipid stores in the important model organisms S. cerevisiae (yeast) and C. elegans (a nematode) are shown, of the integration of nano-particles in skin tumour cells (Squamous Cell Carcinoma) for targeted treatment, and of the integration and proliferation of different mammalian cells in bioengineered cellulose scaffolds for functionalized artificial tissues. With these highlights from our work, we want to bring forward the unique kind of information multi-photon microscopy contributes with and hopefully inspire to new applications.

Our mission is to develop and integrate these emerging microscopy techniques into the biosciences in order to meet the increasing interest and need for visual information on dynamic distributions of essential biomolecules (lipids, carbohydrates, and structural proteins etc.) in living cells & organic matter. In order to fulfill our mission, we have moved the experimental setup from the Physics building into two lab units in the Chemistry/Life Sciences building (Fig. 1).