Vogelbusch optimises important aspect of the bioethanol production from woody raw materials

03-28-2008: Vogelbusch GmbH, which is based in Vienna (Austria), announced that it has applied for a patent for an efficient fermentation process for the high-yield extraction of bioethanol from materials containing hemicellulose. Working in partnership with the Institute of Biotechnology and Biochemical Engineering at Graz University of Technology, the company has succeeded in extracting significantly more ethanol from this raw material than other processes.

The new process aims to boost the ecological and economic efficiency of bioethanol production from alternative raw materials such as wood waste. Although the extraction of bioethanol from these types of raw materials is, in principle, feasible and offers attractive ecological benefits, current practices have thus far only produced small yields of the desired end product. The development from Vogelbusch GmbH significantly contributes to the cost-efficiency of bioethanol produced from hemicellulose-containing raw materials.

The aim of the research was to optimise the process that converts the carbohydrate xylose into ethanol using the yeast Saccharomyces cerevisiae. Xylose is a key intermediate in the production of bioethanol from wood waste, but production processes based on this material are usually relatively inefficient. The reason for this is the imbalanced availability of the substances NAD and NADP ­ which function as co-enzymes during the conversion process and transfer hydrogen groups ­ in the majority of microorganisms. The optimisation work that Vogelbusch has carried out on S. cerevisiae resolves the issue of co-enzyme imbalance, thereby delivering greater efficiency in the conversion of xylose into ethanol. The following specific adjustments have optimised S. cerevisia:

- Introduction of the capacity to synthesise a form of the enzyme xylose reductase with an altered binding site for certain co-enzymes.

- Introduction of the capacity to synthesise the enzyme xylitol dehydrogenase from Galactocandida mastotermitis.

- Introduction of the capacity to synthesise larger volumes of the enzyme xylulosekinase.

The increased efficiency levels in xylose-based ethanol production thus achieved also help to lower the production of unwanted by-products such as glycerine and xylitol. As a result, this optimised strain of S. cerevisiae is able to produce greater ethanol yields than other previously used strains.