Archer Daniels Midland Company

Andriy Voronovsky

Charles Abbas

Andriy Sibirny

Olena Ishchuk

Oleh V Stasyk

Olena B Ryabova

Methods of identifying genes conferring ethanol tolerance in yeasts, genes that confer ethanol tolerance, and mutant strains used to identify such genes are described. A gene herein designated HpETT1 was isolated from the yeast. Expression of HpETT1 in an ethanol sensitive mutantstrain designated 7E complimented ethanol sensitivity of the mutant. When multiple copies of the HpETT1 were integrated into the genome and overexpressed, the transformed strain demonstrated approximately 10-fold greater resistance to ethanol and resistance to the protein misfolding agent AZC. Expression of HpETT1 also increased ethanol tolerance in. HpEtt1 has 39% sequence identity to a previously identified protein fromdenoted MPE1, however, the MPE1 gene does not confer ethanol resistance to the 7E mutant. Another gene from the yeastwas identified that encodes an orthologue protein having 37% identity to HpETT1 herein designated PsETT1 and also confers ethanol resistance to the 7E mutant.

Genes conferring tolerance to ethanol and high temperature for yeasts

Genes SWA2 and GAM1 from the yeast,, encoding &#x3b1;-amylase and glucoamylase, respectively, were cloned and expressed in. The expression was achieved by integration of the SWA2 and GAM1 genes into the chromosome ofunder operably linked to a strong constitutive promoter of the-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, and a xlnD gene coding for &#x3b2;-xylosidase was obtained from the fungus. Co-expression of these genes was also achieved by integration into thechromosome 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&#xb0; C. Further with co expression of the forgoing genes in astrain that overexpresses a pyruvate decarboxylase gene further improved ethanol production.

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Methods and compositions for the production of ethanol from lignocellulosic starting materials are provided herein. Embodiments provide yeast cells of the genuswith one or more modifications, including, for example, an inactive acid trehalase gene, overexpression of xylulokinase, and/or overexpression of heat-shock protein 104.

Methods and compositions for the production of ethanol from lignocellulosic starting materials are provided herein. Embodiments of the invention provide methods of manipulating the carbon flux of a host cell transformed with plasmids of the invention. Plasmids of the invention may include nucleotides that encode pyruvate decarboxylase. In one embodiment, a strain of the thermotolerant yeastthat has been transformed with plasmids and polynucleotides of the invention is provided.

Growing community of inventors

Lviv, Ukraine

Andriy Voronovsky