Aconitic acid exporter (aexA) increases organic acid production in aspergillus

A method of producing 3-hydroxypropionic acid (3-HP), comprising:

• culturing an isolated recombinant Aspergillus fungus in Riscaldati medium, or modified Riscaldati medium under conditions that permit the fungus to produce 3-HP, thereby making 3-HP,
• wherein the fungus comprises:
• an exogenous nucleic acid molecule encoding an aconitic acid exporter (aexA) protein comprising at least 60% sequence identity to SEQ ID NO:
• 2, 3, 4, or 5, operably linked to an exogenous promoter, thereby overexpressing the aexA in the fungus;
• an endogenous or exogenous nucleic acid molecule encoding aspartate 1-decarboxylase (panD);
• an endogenous or exogenous nucleic acid molecule encoding β-alanine-pyruvate aminotransferase (BAPAT);
• and
• an endogenous or exogenous nucleic acid molecule encoding 3-hydroxypropionate dehydrogenase (3-HPDH), and
• wherein the Riscaldati medium comprises 100 g/L glucose, 0.11 g/L KH2PO4, 2.36 g/L (NH4)2SO4, 2.08 g/L MgSO4*7H2O, 0.074 g/L NaCl, 0.13 g/L CaCl2*2H2O, 0.0013 g/L ZnSO4*7H2O, 0.0055 g/L FeSO4*7H2O, 0.0002 g/L CuSO4*5H2O, and 0.0007 g/L MnCl2*4H2O, or
• wherein the modified Riscaldati medium comprises 100 g/L glucose, 0.11 g/L KH2PO4, 2.36 g/L (NH4)2SO4, 2.08 g/L MgSO4*7H2O, 0.074 g/L NaCl, 0.13 g/L CaCl2*2H2O, 20 times 0.0013 g/L ZnSO4*7H2O, 20 times 0.0055 g/L FeSO4*7H2O, 20 times 0.0002 g/L CuSO4*5H2O, and 20 times 0.0007 g/L MnCl2*4H2O.