Optimization of Culture Conditions for Pyrroloquinoline Quinone-Overproducing Mutant Hyphomicrobium denitrificans and...

Pyrroloquinoline quinone (PQQ) is a water-soluble quinone derived from bacteria, known for its antioxidant properties and ability to enhance mitochondrial function. These characteristics make PQQ a promising bioactive molecule for anti-aging applications in dermatology. This study aimed to improve PQQ production by developing a UV-induced mutant strain and optimizing the culture medium, and to evaluate the potential of the produced PQQ as a cosmetic ingredient. The mutant strain, NPP-230, was compared with the wild-type strain, Hyphomicrobium denitrificans ATCC51888, for growth and PQQ production after 96 h of cultivation. The effect of optimized medium on both strains was also assessed. The PQQ obtained from the cultures was evaluated for skin-related biological activities, including collagen synthesis, melanin inhibition, tyrosinase inhibition, and L-3,4-dihydroxyphenylalanine (L-DOPA) oxidation inhibition. The mutant strain cultured in optimized medium showed higher biomass and PQQ production than the wild type. Furthermore, PQQ promoted collagen synthesis and inhibited melanin production and tyrosinase activity in a concentration-dependent manner. These findings indicate that PQQ production in H. denitrificans can be enhanced under optimized conditions, and that the produced PQQ exhibits anti-aging and skin-whitening properties.