Genes SWA2 and GAM1 from the yeast, Schwanniomyces occidentalis, encoding α-amylase and glucoamylase, respectively, were cloned and expressed in H. polymorpha. The expression was achieved by integration of the SWA2 and GAM1 genes into the chromosome of H. polymorpha under operably linked to a strong constitutive promoter of the H. polymorpha-glyceraldehyde-3-phosphate dehydrogenase gene (HpGAP. Resulting transformants acquired the ability to grow on a minimal medium containing soluble starch as a sole carbon source and can produce Ethanol at high-temperature fermentation from starch up to 10 g/L. A XYN2 gene encoding endoxylanase was obtained from the fungus Trichoderma resee, and a xlnD gene coding for &bgr;-xylosidase was obtained from the fungus Aspergillus niger. Co-expression of these genes was also achieved by integration into the H. polymorpha chromosome under control of the HpGAP promoter. The resulting transformants were capable of growth on a minimal medium supplemented with birchwood xylan as a sole carbon source. Successful expression of xylanolytic enzymes resulted in a recipient strain capable of fermentation of birchwood xylan to ethanol at 48° C. Further with co expression of the forgoing genes in a H. polymorpha strain that overexpresses a pyruvate decarboxylase gene further improved ethanol production.