New green”  by-products from bio-ethanol production

  1. Different fractions of distiller’s waste as a source of protein-rich “green” fermentation media. In industrial cultivation of microorganisms, protein components from meat or soy are currently the most common sources of amino acids required for microbial growth. For a wide range of bio-products, especially those for human consumption, there are strong market demands to avoid meat- and soy-derived proteins. We have initiated such projects in order to develop protein-rich “green” fermentation substrates.
  1. Use of components from distiller’s waste as drying protectants for microbial bio-products. A prerequisite for commercial use of viable microorganisms is that they can be formulated (stabilised) with maintained viability and long storage stability.There are indications that certain components from distiller’s waste can function as drying protectants for freeze drying and as carrier materials for fluidised bed drying of microorganisms.

  1. For efficient and safe use of distiller’s waste as fermentation media or drying protectant, it is of great importance to characterise its contents with respect to carbohydrates, proteins, amino acids, heavy metals, pH, etc. The proposed project will focus on chemical analysis of the water-soluble fraction of several different distiller’s wastes, with special emphasis on carbohydrates. This will be achieved by use of nuclear magnetic resonance spectroscopy in conjunction with chromatographic techniques and chemical derivatization methods. Other chemical analyses (proteins, amino acids, heavy metals) will be performed by commercial laboratories. There will also be some focus on the non-soluble fraction of distiller’s grain with respect to dry weight, fiber contents and mechanical properties, among others. Microbiological characterisation of the distiller’s waste will also be performed within the proposed project, and this will include determination of the number of lactic acid bacteria, total bacteria, yeasts and moulds.



  • Chemical characterisation, NMR, chromatography
  • Cultivation/fermentation of microorganisms
  • Microbial formulation, freeze- and fluid bed drying




    Anders Broberg, Dept. of Chemistry, SLU in Uppsala,, +46 (0) 18 672217
    Sebastian Håkansson, Dept. of Microbiology, SLU in Uppsala,
    Thomas Eberhard, Dept. of Microbiology, SLU in Uppsala,