The Microbial Palette: From Bioprospecting to Genetic Engineering of Microbial Pigments

Microbial pigments are secondary metabolites that represent promising alternatives to synthetic colorants, offering advantages even over other natural sources. These pigments can be produced independently of seasonality and at low cost, especially when using agro-industrial residues as substrates, and their production can be optimized. Bioprospecting of microorganisms in unexplored environments offers valuable opportunities to discover safer and more efficient pigment producers. Brazil harbors vast biodiversity across multiple biomes, providing a rich reservoir for such discoveries. Biomes such as the Atlantic Forest, Pampa, Pantanal and Coastal Marine are still poorly explored with respect to the bioprospecting of pigment-producing microorganisms, representing a valuable opportunity for the discovery of novel pigments. However, several bottlenecks still hinder the regulatory approval of microbial pigments, particularly those produced by filamentous fungi, due to the frequent co-production of mycotoxins. To overcome these challenges, genetic engineering tools are crucial for eliminating mycotoxin co-production. CRISPR-Cas9, CRISPRi and CRISPR-Cpf1 have become the most widely used techniques for this purpose. Another key application of CRISPR is the enhancement of pigment yields, which can accelerate the industrial adoption of microbial pigments. Together, these two strategies, bioprospecting new environments and genetic engineering, can significantly speed up the transition from synthetic pigments to safer and more eco-friendly microbial alternatives.