Formation of 5-aminolevulinic acid under aerobic/dark condition by a mutant of Rhodobacter sphaeroides

A mutant strain CR-17 ofRhodobacter sphaeroides was characterized by the low activity of 5-aminolevulinic acid dehydratase (ALAD) compared to the wild-type strain. Without addition of levulinic acid (inhibitor of ALAD), the mutant secreted 5-aminolevulinic acid under anaerobic/light (64.5 μM) or under microaerobic/dark (32 μM) conditions; 82.5 μM of ALA was secreted under aerobic/dark condition with addition of 15 mM levulinic acid.