Bioethanol from straw and algae

The joint research project Bioethanol ¨Optimized conversion of cellulose and hemicellulose from corn straw in sugar monomers by the combined use of thermal pressure and novel enzyme sources¨ is funded by the Bundesministerium für Ernährung, Landwirtschaft und Verbraucherschutz (BMELV) via the Fachagentur Nachwachsende Rohstoffe e.V. (FNR). In collaboration with the Institute of Microbiology and Wine Research, Johannes Gutenberg University, Mainz, SeqLab GmbH, Göttingen and ASA Spezialenzyme GmbH, Wolfenbüttel,  the central objectives are an optimized transformation of straw cellulose and hemicellulose into monosaccharides.  

Increasing costs of petroleum and agricultural food products have shifted the attention more towards straw, trees, nonfood crops, and other low-cost agricultural waste materials (second generation resources). The transformation of plant and algal biomass into saccharides requires the separation and depolymerization of cellulose, hemicellulose and lignin. These saccharides can be used for production of building-block chemicals (such as ethanol) by fermentation or transformation (enzymatically or chemically). However, the high amount of cellulose and hemicellulose in corn straw, woody and herbaceous crops remains a key challenge for their efficient and cost-effective depolymerization. In biorefineries lignocellulose is pretreated using chemical and physical procedures to make the biomass matrix more accessible to enzymes. As a sustainable alternative microorganisms or microbial communities can assist either in the decomposition or directly decompose and transform plant and algae derived polysaccharides.

Within the Bioethanol project we will investigate microbial communities decomposing straw in natural continuous cultures. Samples will be taken from a graduation tower packed with straw and the gut of straw consuming termites. Straw decomposing microorganisms will be enriched and isolated from these samples. Microbial strains or microbial communities isolated will be screened for their potential to decompose plant and algae derived biomass.
    In the second part of the Bioethanol project we will screen genomes of type strains (i) to predict their polysaccharide decompositing potential indicated by the number and diversity of genes encoding for carbohydrate active enzymes (CAZyme) and (ii) to gain further insights into whether strains from different ecological habitats possess distinct biochemical pathways and sets of CAZymes. This part of the project is in close collaboration with the Phylogenomics group and the Department Microbial Ecology and Diversity Research. Motivated by their great potential for biotechnological applications we have focused on type strains of the families Flavobacteriaceae (Bacteria) and Halobacteriaceae (Archaea).

Project Partner at the DSMZ
Dr. Richard Hahnke
Dr. Brian J. Tindall