Optimization of fermentation, purification, and properties of blue pigment produced from Quambalaria cyanescens QY229

Abstract

Abstract Aim Blue pigments have broad applications in foods, cosmetics, and clothing. However, natural blue pigments are rare. At present, the majority of blue pigments for sale are chemically synthetic. Owing to the safety risks of chemical pigments, it is an urgent demand to develop novel natural blue pigments. Methods and Results The fermentation medium and culture conditions of blue pigment produced by Quambalaria cyanescens QY229 were optimized by Plackett–Burman (PB) experimental design and response surface methodology (RSM) for the first time. The stability, bioactivity, and toxicity of the obtained blue pigment were studied after isolation and purification. Conclusion The results showed that the optimal fermentation parameters were 34.61 g·L−1 of peptone concentration, 31.67°C of growing temperature, and 72.33 mL of medium volume in a 250-mL flask, and the yield of blue pigment reached 348.2 ± 7.1 U·mL−1. QY229 blue pigment is stable to light, heat, pH, most metal ions, and additives, and has certain antioxidant and inhibitory activity of α-glucosidase in vitro. QY229 blue pigment at concentrations of 0–1.25 mg·mL−1 was nontoxic to Caenorhabditis elegans in an acute toxicity trial.