Membrane protein insertion in liposomes: implications for the synthetic cell

The formation of a synthetic cell is a major challenge within the field of synthetic biology. Here the goal is to create a living cell bottom-up from individual components that is capable of growth and division. One of the requirements for this will be the synthesis of membrane proteins and their correct insertion into the synthetic cell membrane. For most membrane proteins, this insertion does not occur spontaneously but is facilitated by the translocon, a protein complex ubiquitously present in all forms of life. This thesis focuses on the functioning and optimization of the translocon from Escherichia coli with regard to the synthetic cell. Furthermore, it introduces an optimized method to form giant unilamellar vesicles (GUVs) containing the translocon

Release of CO2 and CH4 from lakes and drainage ditches in temperate wetlands

Shallow fresh water bodies in peat areas are important contributors to greenhouse gas fluxes to the atmosphere. In this study we determined the magnitude of CH4 and CO2 fluxes from 12 water bodies in Dutch wetlands during the summer season and studied the factors that might regulate emissions of CH4 and CO2 from these lakes and ditches. The lakes and ditches acted as CO2 and CH4 sources of emissions to the atmosphere; the fluxes from the ditches were significantly larger than the fluxes from the lakes. The mean greenhouse gas flux from ditches and lakes amounted to 129.1 ± 8.2 (mean ± SE) and 61.5 ± 7.1 mg m-2 h-1 for CO2 and 33.7 ± 9.3 and 3.9 ± 1.6 mg m-2 h-1 for CH4, respectively. In most water bodies CH4 was the dominant greenhouse gas in terms of warming potential. Trophic status of the water and the sediment was an important factor regulating emissions. By using multiple linear regression 87% of the variation in CH4 could be explained by PO4 3- concentration in the sediment and Fe2+ concentration in the water, and 89% of the CO2 flux could be explained by depth, EC and pH of the water. Decreasing the nutrient loads and input of organic substrates to ditches and lakes by for example reducing application of fertilizers and manure within the catchments and decreasing upward seepage of nutrient rich water from the surrounding area will likely reduce summer emissions of CO2 and CH4 from these water bodie