Engineered Bacteria Produce Octopus Pigment Xanthommatin at Gram Scale

Researchers at the University of California San Diego announced a significant development in November 2025 concerning the production of xanthommatin, the ommochrome pigment crucial for the camouflage capabilities of octopuses. Historically, synthesizing this complex molecule outside of an animal presented substantial chemical barriers, with previous synthetic attempts proving slow, costly, and low-yielding due to its intricate structure. This new biological approach moves the compound from a laboratory curiosity toward a potentially viable commercial material by achieving production titers up to a thousand times greater than earlier methods.

The innovation centers on reprogramming the common soil bacterium Pseudomonas putida using a novel system termed "biosynthesis coupled to growth" (GrowBio). This intelligent system directly links the survival of the microbe to the creation of the target pigment, overcoming the common issue where high-yield production pathways inhibit cellular growth. The researchers engineered a metabolic dependency within the strain: the biosynthesis of xanthommatin from its precursor, tryptophan, releases formate, a one-carbon (C1) moiety. The engineered P. putida was designed as a 5,10-methylenetetrahydrofolate auxotroph, meaning it required this C1 component to grow. Consequently, the formate released during pigment generation served as the essential growth driver, establishing a self-sustaining feedback mechanism where pigment creation fueled biomass generation.

This bioproduction process was further refined through adaptive laboratory evolution, a technique that utilized growth rate selection to allow the microbes to autonomously improve their output. This rigorous, data-driven refinement, which incorporated robotic evolution, streamlined the process to the gram-scale using simple carbon sources like glucose. This breakthrough signals a shift away from environmentally taxing chemical synthesis and natural extraction, which was deemed unviable for xanthommatin due to technical and ethical constraints.

The ability to cleanly and reproducibly manufacture xanthommatin opens avenues across several industries. Beyond its role in cephalopod camouflage, the pigment contributes to the coloration of insects like monarch butterflies. Furthermore, its utility extends to advanced materials, as its redox-dependent absorption profile allows it to function in photochromic coatings that shift hue upon light exposure. Studies also indicate that xanthommatin can enhance the UVA and UVB absorption properties of conventional UV filters by over 50%, positioning it as a multifunctional cosmetic ingredient that proved non-mutagenic in bacterial assays.

Senior author Bradley Moore and the research team from UC San Diego concluded that this growth-coupled strategy is highly versatile. They suggest this model, which utilizes biology as an efficient factory, can be adapted for the large-scale manufacturing of numerous high-value compounds, including specialized medicines and functional materials, confirming nature as a profound source for designing sustainable, high-performance materials.