Research fields
Head: Dr. FalkoMatthes (komm.) , Prof. Dr. Gotthard Kunze
The main field of research in the yeast genetics unit is the non-conventional, non-pathogen yeast Arxula adeninivorans and its use for the production of recombinant proteins, as a gene-donor and biocatalyst for new biotechnological products. It is also utilised as the microbial component in biosensors for the analysis of waste water, urine and blood, for the monitoring of feed and food and for medical investigations.
The yeast A. adeninivorans was used already in the 1980's for the production of single cell protein in Malchin (Mecklenburg-Western Pomerania) because of its rapid growth, extraordinarily high cell titers and its braod substrate spectrum. Parallel to the biotechnological utilisation investigations took place regarding its taxonomical classification and its physiology. In cooperation with the department yeast genetics of the University of Greifswald molecular tools were developed for the production of mutants by chemical mutagenesis, protoplast fusion and mitotic segregation as the basis for further improvement of A. adeninivorans as host for the production of new biotechnological products and the construction, establishment and validation of microbial biosensors. Such biosensors for the monitoring of food and environmental conditions as well as medical and pharmaceutical purposes were developed starting from the 1990's in the working group yeast genetics under the direction of Professor Dr. habil. Gotthard Kunze.
The genome of A. adeninivorans
Beginning in the early 1990's the genome of A. adeninivorans was analysed in detail by DNA reassociation studies. At the same time physiological studies were accomplished concerning usable substrates as carbon and nitrogen sources and the corresponding metabolic pathways were examined. In this context the first transgenic A. adeninivorans strains were constructed. In the following years several A. adeninivorans genes and its 25S rDNA were isolated and characterised leading to establishment of a transformation/expression system for the production of recombinant proteins in transgenic yeast strains. This system called Xplor®2 was further developed to a modular platform (expression modules, selection marker modules, ARS modules, Chaperon modules) for fast and effective construction of desired plasmids. In order to make this platform usable for the construction of custom-made transgenic production strains with high acceptance, it was established in close cooperation with small and medium-sized enterprises (KMUs) like the ARTES Biotechnology GmbH in Langenfeld. The main advantage of this patent-registered platform is that only essential DNA sequences are transformed avoiding undesired E. coli sequences and resistance genes. Since the expression modules stably integrate in the A. adeninivorans genome the transformed yeast strains show a high mitotic stability, essential for biotechnological application.
In 2010 the complete genome of A. adeninivorans was sequenced and annotated at the IPK making the Xplor®2 system even more attractive.