IISc Researchers Decode Lac Insect's Laccaic Acid Production Mechanism

In a groundbreaking study conducted by researchers at the Indian Institute of Science (IISc), the intricate process through which the lac insect synthesizes laccaic acid—a key component in the production of lac pigment—has been elucidated. This pigment, valued in the realms of food coloring, textiles, handicrafts, and folk art, has long been a subject of scientific inquiry due to the mysterious nature of its biosynthesis. The findings were published in a recent paper on June 18, 2025.

The lac insect, primarily found on specific tree species such as the flame of the forest, derives its nourishment from the sugary sap of these trees while simultaneously secreting a sticky resin known as shellac. Historically, scientists grappled with the enigma of laccaic acid production, with previous genomic studies yielding no conclusive evidence of the necessary genes within the insect itself. "For decades, researchers have sought after the genetic basis for laccaic acid synthesis, but the answers remained elusive," stated Dr. Shantanu Shukla, Assistant Professor in the Department of Developmental Biology and Genetics at IISc.

The breakthrough came when the IISc team discovered that the laccaic acid is actually synthesized by a symbiotic yeast-like organism residing within the insect. This organism harbors the genetic framework essential for the pigment's production, including genes coding for enzymes that facilitate the formation of aromatic molecules, which serve as building blocks for laccaic acid. "The yeast-like fungus is integral to the insect’s lifecycle, as it provides essential components that the insect cannot produce or obtain from its diet," added Dr. Shukla.

To pinpoint the source of laccaic acid production, researchers sequenced the entire microbiome of the lac insect, identifying two primary candidates: a bacterium belonging to the Wolbachia genus and the aforementioned yeast-like fungus. Notably, the yeast-like organism possessed the complete set of genes requisite for laccaic acid synthesis, while neither the lac insect nor the Wolbachia bacterium contained these genes. This discovery marks a significant advancement in understanding the symbiotic relationships in nature, particularly in terms of nutrient exchange between organisms.

Dr. Anjali Mehta, an entomologist at the University of California, Berkeley, commented on the implications of this research: "The findings not only clarify the biological processes behind lac pigment production but also highlight the importance of microbial symbionts in insect physiology. This could pave the way for biotechnological applications in pigment synthesis."

The study further elaborates on the role of tyrosine, an amino acid vital for laccaic acid production, which the lac insect is incapable of producing itself. Instead, it relies on its symbiotic partner to supply this essential compound. "This is a classic example of mutualism in nature, where one organism provides nutrients to another in exchange for habitat," explained Dr. Lisa Wang, a microbiologist at Stanford University who specializes in symbiotic relationships.

The implications of this discovery extend beyond biological curiosities; they may influence the economic landscape of the lac industry, predominantly centered in India, which has been a leading producer of lac pigment for thousands of years. According to the Ministry of Textiles, Government of India, the lac industry supports the livelihoods of thousands of artisans and small-scale producers across the country.

As the global demand for natural pigments increases, understanding and optimizing the biological processes behind their production can enhance sustainable practices within the industry. The IISc findings not only contribute to the scientific community's understanding of pigment biosynthesis but also underscore the potential for biotechnological innovation in the sustainable production of natural dyes.

Looking ahead, researchers at IISc plan to further investigate the metabolic pathways involved in laccaic acid production and explore potential applications in synthetic biology. The ongoing research highlights the intricate relationships between organisms and the potential benefits of harnessing these interactions for ecological and economic sustainability.