Production of 5-Aminolevulinic Acid by Heterotrophic Cultures of Chlorella regularis YA-1 and the Mutant YA-603 Strains

Abstract Effects of pH and temperature on 5-aminolevulinic acid(ALA) production were investigated in the heterotrophic cultures of newly screened Chlorella regularis YA-1. The optimum pH and temperature were 6.0 and 33°C, respectively. 1.96 mM of ALA was produced extracellularly by the YA-1 strain under the optimum conditions. The pH was found to be more critical than temperature for ALA production. Moreover, it was suggested that the activity of ALA production and the inhibitory effect of levulinic acid for ALA dehydratase were higher at a lower pH. One of the mutant strains, the YA-603 strain, obtained from the 1-methyl-3-nitro-1-nitoroso-guanidine (NTG) treatment of the YA-1 strain, demonstrated higher activity of ALA production than the YA-1 strain, and extracellularly produced 2.40 mM of ALA under the optimum conditions for the YA-1 Strain.