Optimized carotenoid production and antioxidant capacity of gordonia hongkongensis

Abstract

The current emphasis within the cosmetic market on sustainable ingredients has heightened the exploration of new sources for natural, active components. Actinomycetota, recognized for producing pigments with bioactive potential, offer promising functional cosmetic ingredients. This study aimed to optimize pigment and antioxidant metabolite production from the Gordonia hongkongensis strain EUFUS-Z928 by implementing the Plackett-Burman experimental design and response surface methodology. Extracts derived from this strain exhibited no cytotoxic activity against human primary dermal fibroblast (HDFa, ATCC® PCS-201-012™, Primary Dermal Fibroblast; Normal, Human, Adult). Eight variables, including inoculum concentration, carbon and nitrogen source concentration, NaCl concentration, pH, incubation time, temperature, and stirring speed, were analyzed using the Plackett-Burman experimental design. Subsequently, factors significantly influencing pigment and antioxidant metabolite production, such as temperature, inoculum concentration, and agitation speed, were further optimized using response surface methodology and Box-Behnken design. The results demonstrated a substantial increase in absorbance (from 0.091 to 0.32), DPPH radical scavenging capacity (from 27.60% to 84.61%), and ABTS radical scavenging capacity (from 17.39% to 79.77%) compared to responses obtained in the isolation medium. The validation of the mathematical model accuracy exceeded 90% for all cases.