Methods for improving malic acid production in filamentous fungi

A filamentous fungal host cell comprising a heterologous first polynucleotide encoding a C4 dicarboxylic acid transporter, wherein the C4 dicarboxylic acid transporter is selected from the group consisting of:

• (a) a C4 dicarboxylic acid transporter comprising an amino acid sequence having at least 60% sequence identity with SEQ ID NO:
• 8, SEQ ID NO:
• 34, or SEQ ID NO:
• 36;
• (b) a C4 dicarboxylic acid transporter encoded by a polynucleotide that hybridizes under low stringency conditions with SEQ ID NO:
• 7, SEQ ID NO:
• 33, SEQ ID NO:
• 35, SEQ ID NO:
• 37, or a full-length complementary strand thereof;
• (c) a C4 dicarboxylic acid transporter encoded by a polynucleotide comprising a nucleotide sequence having at least 60% sequence identity with SEQ ID NO:
• 7, SEQ ID NO:
• 33, SEQ ID NO:
• 35, or SEQ ID NO:
• 37;
• (d) a C4 dicarboxylic acid transporter variant comprising a substitution, deletion, and/or insertion of one or more (several) amino acids of the mature polypeptide of SEQ ID NO:
• 8, SEQ ID NO:
• 34, or SEQ ID NO:
• 36;
• and
• (e) a fragment of the C4 dicarboxylic acid transporter of (a), (b), (c), or (d) that has C4 dicarboxylic acid transporter activity;
• and wherein the filamentous fungal host cell is capable of secreting increased levels of C4 dicarboxylic acid compared to the filamentous fungal host cell without the heterologous first polynucleotide encoding the C4 dicarboxylic acid transporter when cultivated under the same conditions.