Parameters for sustainable and demand-oriented biogas production

............................................................................................................................................. 4 Introduction ........................................................................................................................................ 7 Renewable energies in Germany ...................................................................................................... 7 Biogas development in Germany ...................................................................................................... 9 Biogas substrates............................................................................................................................. 11 Sustainable biogas production ........................................................................................................ 13 Organic agriculture in Germany ...................................................................................................... 16 Biogas production on organic farms ............................................................................................... 18 Future role of biogas production .................................................................................................... 20 Motivation of doctoral thesis .......................................................................................................... 23 References ....................................................................................................................................... 24 Primary Publications .......................................................................................................................... 29 Manuscript 1 Characterisation of biogas plants on organic farms and potentials for improvement ................... 30 Manuscript 2 Stable carbon isotopes reveal that silage quality – not farming system – drives carbon degradation in anaerobic batch fermentations .............................................................................. 45 Manuscript 3 Functionally redundant but dissimilar microbial communities within biogas reactors treating maize silage in co-fermentation with sugar beet silage. ................................................................. 72 Additional Publications ...................................................................................................................... 83 Additional Information ...................................................................................................................... 84 Acknowledgments ........................................................................................................................... 84 Declaration of independent scientific work .................................................................................... 85 Curriculum vitae .............................................................................................................................. 86