GENETICALLY MODIFIED MICROORGANISMS CAPABLE OF PRODUCING BETA-GLUCANS AND METHODS FOR PRODUCING BETA-GLUCANS

摘要

The present invention relates to genetically modified microorganisms capable of producing beta-glucans, characterized in that the genetically modified microorganism overexpresses (i) a polynucleotide encoding a polypeptide having 1,3-β-D-glucan synthase-activity, and/or (ii) a polypeptide having 1,3-β-D-glucan synthase-activity, compared to a corresponding non-modified control microorganism of the same strain. The present invention also relates to the use of a polynucleotide encoding a polypeptide having 1,3-β-D-glucan synthase-activity or the use of such a polypeptide for producing β-glucans. Furthermore, the present invention relates to methods for producing β-glucans comprising the introduction of a promoter upstream of a polynucleotide encoding a polypeptide having 1,3-β-D-glucan synthase-activity thereby increasing the expression of the polynucleotide, or a polynucleotide encoding a polypeptide having 1,3-β-D-glucan synthase-activity into a microorganism being able to synthesize β-glucans.

主权项

1. A genetically modified microorganism capable of producing a polymer consisting of a linear main chain of β-D-(1-3)-glucopyranosyl units having a single β-D-glucopyranosyl unit (1-6) linked to a β-D-glucopyranosyl unit of the linear main chain with an average branching degree of about 0.3, characterized in that said genetically modified microorganism overexpresses (i) a polynucleotide encoding a polypeptide having 1,3-β-D-glucan synthase activity, wherein said polynucleotide comprises a nucleotide sequence having at least 70% sequence identity to the nucleotide sequence of SEQ ID NO: 3, SEQ ID NO: 7, SEQ ID NO: 11, or SEQ ID NO: 15, and/or (ii) a polypeptide having 1,3-β-D-glucan synthase activity, wherein said polypeptide comprises an amino acid sequence having at least 70% sequence identity to the amino acid sequence of SEQ ID NO: 8 or SEQ ID NO: 16, compared to a corresponding non-modified control microorganism of the same strain.