Microbial pigments as sustainable bio-products: Extraction techniques, optimization, and applications

Abstract:

The growing preference for natural and eco-friendly colorants has intensified research into microbial pigments as sustainable alternatives to synthetic dyes. Microorganisms such as fungi, bacteria, yeast, and algae are valuable sources of diverse bio-pigments, including carotenoids, melanin, prodigiosin, and polyketides like Monascus pigments. These compounds not only impart attractive colors but also exhibit antioxidant, antimicrobial, and anticancer properties. Efficient pigment extraction is essential for maximizing yield and purity, with conventional methods like solvent extraction increasingly complemented by enzyme-assisted, ultrasound, and supercritical fluid techniques. Extraction efficiency depends on culture parameters such as pH, temperature, substrate composition, and oxygen availability, which influence both pigment synthesis and stability. Recent advances in bioprocess optimization and green extraction methods have improved pigment recovery while reducing environmental impact. However, challenges remain in large-scale production, color stability, and regulatory approval for food applications. Overall, microbial color extraction represents a promising, sustainable, and multifunctional approach that aligns with global trends toward natural, health-promoting, and clean-label products.