Compounds From Symbiotic Bacteria Kill Pathogens

Biological Strategy

Eurasian hoopoe

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Protect From Microbes

In living systems, microbes play important roles, such as breaking down organic matter and maintaining personal and system health. But they also pose threats. Bacteria can be pathogens that cause diseases. Some bacteria create colonies called biofilms that can coat surfaces, reducing their effectiveness–for example, inhibiting a leaf’s ability to photosynthesize. Living systems must have strategies for protecting from microbes that cause disease or become so numerous that they create an imbalance in the system. At the same time, living systems must continue living in harmony with other microbes. Some living systems kill microbes. Others repel without killing to reduce the chances that microbes will adapt to the lethal strategy and become resistant to it. For example, some pea seedlings exude a chemical that inhibits biofilm buildup.

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Cooperate/Compete Between Different Species

From parasitism to mutualisms, there are endless interactions between organisms in nature. Interactions between species that lead to a negative outcome for one species are known as competition. Cooperation occurs when organisms work together for the benefit of each organism or species. While competition often occurs over resources or mates, the more biologists have begun to look for examples of cooperation in nature, the more they have found. For example, around 90% of plants have a beneficial partnership with fungi. Fungi provide the plant with nutrients such as nitrogen and phosphorus, in exchange for sugars from the plant.

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Birds

Class Aves (“bird”): Eagles, hawks, sparrows, parrots

Birds are evolutionary engineering marvels. They are descended from dinosaurs, but are far from our idea of heavy, scaly reptiles. Of the specific adaptions that set them apart, most notable is flight—although some mammals can fly, birds take the prize for abundance in the skies. Many birds have hollow, lightweight skeletons and specially-designed wings to help them stay aloft. They also have feathers made of keratin that help them stay warm, attract mates, and improve navigation and aerodynamics in flight. In contrast to their dinosaur ancestors, they lack true teeth and have replaced them with specialized beaks and bills.

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The uropygial glands of hoopoe birds contain a symbiotic bacteria that secrete antiseptics targeted at feather-eating bacteria.

Introduction

The Eurasian hoopoe (Upupa epops), known for its striking feathers and unique crown, has a special way of keeping its plumage healthy. This bird, which lives in open woodlands, grasslands, and other habitats across Europe, Asia, and North Africa, faces threats from harmful bacteria that can break down its feathers. To protect itself, the hoopoe relies on a partnership with bacteria living in its uropygial , a small gland at the base of its tail. These bacteria produce natural chemicals that stop harmful microbes from damaging the bird’s feathers.

The Strategy

The hoopoe’s uropygial gland contains bacteria called Enterococcus faecalis, which produce special compounds known as bacteriocins. These compounds are like natural antibiotics, and they work to kill harmful microbes such as Bacillus licheniformis. This harmful bacterium is common in the wild and produces an enzyme that breaks down keratin, the tough that makes up most of a feather. If left unchecked, B. licheniformis can weaken feathers, making it harder for birds to fly, stay warm, or attract mates.

When a hoopoe preens itself, it spreads the oily secretion from its uropygial gland onto its feathers. This oil carries the bacteriocins, which attack the harmful bacteria by breaking open their cells, stopping them from producing the enzymes that degrade keratin. Laboratory experiments have shown that feathers treated with the hoopoe’s bacteria or their bacteriocins stay much healthier than untreated feathers exposed to B. licheniformis. The protection extends not only to the feathers but also to pure keratin, demonstrating the powerful effects of these natural chemicals.

This protective system is especially important during the nesting season, when hoopoes face a higher risk of infections. Females stay in the nest for long periods while incubating eggs, and the nest environment can become dirty and humid—conditions that encourage bacterial growth. By relying on their bacterial partners, hoopoes ensure their feathers stay intact, which is critical for their survival and their chicks’ development.

The Potential

The hoopoe’s clever use of bacteria offers valuable lessons for humans. By studying how these natural bacteriocins work, scientists could develop new, eco-friendly ways to fight harmful microbes. For example, we could create safer alternatives to synthetic antibiotics, which often cause environmental harm. Industries like farming, textile preservation, and even medicine could benefit from treatments inspired by the hoopoe’s strategy, such as coatings to protect materials from bacterial damage or new ways to keep wounds clean and free of infection. The hoopoe’s partnership with bacteria shows how nature’s innovations can inspire solutions to some of our biggest challenges.

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Last Updated January 29, 2025

References

Journal article

Symbiotic bacteria living in the hoopoe's uropygial gland prevent feather degradation

Journal of Experimental Biology | 30/10/2009 | M. Ruiz-Rodriguez, E. Valdivia, J. J. Soler, M. Martin-Vivaldi, A. M. Martin-Platero, M. Martinez-Bueno

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