Stoffumwandlung mit Biokatalysatoren. Modifizierung der Glucoamylase von Arxula adeninivorans in Hefe Bericht aus Forschung und Entwicklung. Endbericht

Abstract

By immunoscreening the glucoamylase gene (GAA-gene) was isolated from the yeast Arxula adeninivorans. The gene could be identified on a DNA-fragment on chromosome 2 from Arxula and comprises 1872 bp. Within the N-terminal end of the protein the first 16 amino acids are the signal sequence for entering the endomembrane system. Comparing the amino acid sequence from the glucoamylase with those of other fungal glucoamylases it is shown that our glucoamylase has a high homology with the glucoamylase from Rhizopus oryzae (32.6%). No homology could be detected to the glucoamylase from Schwanniomyces occidentalis. By using Saccharomyces cerevisiae promoters in autonomously replicating plasmids it was possible to express the isolated GAA-gene in S. cerevisiae and Kluyveromyces lactis. The transformants secreted more than 90% of the expressed glucoamylase into the culture medium. The glucoamylases secreted by all three microorganism has similar biochemical properties but is expressed and secreted more rapidly in the S. cerevisiae transformants than in A. adeninivorans or K. lactis transformants. (orig.)SIGLEAvailable from TIB Hannover: F95B1130+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman