Feasibility and durability of a first-of-a-kind, sustainable biologic paint using bacterial pigment and protein binder

Abstract

Conventional paints present notable health and environmental hazards due to the presence of heavy metal-based pigments and the emission of volatile organic compounds (VOCs) from synthetic binders. Prior research has shown that genetically engineered microorganisms, such as Escherichia coli, can biosynthesize pigments that offer reduced environmental impact. However, biologically derived pigments to date have been formulated with VOC-emitting binders. Casein, a natural, VOC-free binder used since antiquity, represents a promising alternative, though its compatibility with biologically derived pigments has not been systematically evaluated. Bacterial pigments and protein binders are sustainable because they are derived from renewable biological sources. This study investigates a novel paint formulation combining E. coli–derived pigment with a casein-based binder and compares its spectral durability to two mineral-based commercial paints under varied environmental conditions. Spectral intensity analysis demonstrated that biologic paint retained color stability comparable to both commercial standards; although four statistically significant differences were observed, all were below the threshold of human visual perception. These results demonstrate that coupling biologically derived pigments with a casein binder can yield an effective, environmentally safer alternative to conventional paint systems.