Compounds From Symbiotic Bacteria Kill Pathogens

Biological Strategy

Eurasian hoopoe

AskNature Team

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.

Search this Function

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.

Search this Function

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.

Search this Living System

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

Bacteria that consume the keratin of bird feathers are obvious enemies of birds. Without their plumage, they could not fly and would not be able to regulate their internal temperatures. The hoopoe bird prevents growth of these keratin-consuming bacteria by cultivating populations of symbiotic bacteria within special glands accessed during preening. These bacterial allies secrete antiseptics called bacteriocins that can kill the keratin-consuming bacteria. However, it appears that the birds apply enough of the antiseptic to slow the pace of keratin degradation rather than totally wiping out the bacterial parasites perhaps in an effort to ward off an aquired resistance.

Last Updated August 23, 2016

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

embedly preview

AskNature