Mutant of genus Rhizopus

A method for improving organic acid productivity of a Rhizopus fungus, comprising:

• deleting or inactivating a pdc gene in the Rhizopus fungus, wherein
• the pdc gene is at least one polynucleotide selected from the group consisting of:
• a polynucleotide consisting of the nucleotide sequence set forth in SEQ ID NO:
• 1;
• a polynucleotide consisting of a nucleotide sequence having at least 90% identity to the nucleotide sequence set forth in SEQ ID NO:
• 1 and that encodes a polypeptide which has pyruvate decarboxylase activity;
• a polynucleotide comprising a nucleotide sequence that has 1-20 deletions, insertions, substitutions or additions of nucleotides as compared to the nucleotide sequence set forth in SEQ ID NO:
• 1 and that encodes a polypeptide which has pyruvate decarboxylase activity;
• a polynucleotide encoding a polypeptide which consists of the amino acid sequence set forth in SEQ ID NO:
• 2;
• a polynucleotide encoding a polypeptide which consists of an amino acid sequence having at least 90% identity to the amino acid sequence set forth in SEQ ID NO:
• 2 and that has pyruvate decarboxylase activity;
• and
• a polynucleotide encoding a polypeptide which comprises an amino acid sequence that has 1-10 deletions, insertions, substitutions or additions of amino acid residues as compared to the amino acid sequence set forth in SEQ ID NO:
• 2 and that has pyruvate decarboxylase activity;
• and culturing the fungus to produce the organic acid,
• wherein the organic acid is selected from the group consisting of fumaric acid, lactic acid, succinic acid, malic acid, and α-ketoglutaric acid,
• and wherein production of the organic acid is improved in the Rhizopus fungus compared to the production of the organic acid before deletion or inactivation of the pdc gene.