Is feather biodegradable? (17 applications of feathers).

This article shall answer the question, ” is feather biodegradable?”.

It shall also cover areas such as:

  • Types of feathers.
  • Importance of feathers to birds.
  • Uses of feathers by humans.
  • The biodegradation process of feathers.
  • The effects of feathers on the environment.

Is feather biodegradable?

Yes, feathers are a natural, organic material formed on the bodies of birds. They are composed of natural keratin protein, the same protein found in human fingernails or animal hooves.

Although keratin is a tough protein that takes longer to break down as compared to other biomolecules, nonetheless, it breaks down into small biomass which does not affect the environment.

Feathers can be biodegradable naturally in the environment or can be used in compost to enrich the compost with nitrogen minerals.

The types of feathers depend on different birds. Feathers come in different sizes and colors and they also have different functions.

Biodegradation process of feathers.

Feathers are a major byproduct of the poultry industry. They are made of keratin proteins which are naturally resistant to degradation by protease enzymes of bacteria and fungi.

This resistance to protease degradation means that feathers can be a major environmental pollutant if unchecked.

However, feathers are broken down by bacterial and fungal keratinase enzymes which break the keratin protein into small amino acid molecules.

The biodegradation process involves bacteria and fungi.

Biodegradation is the process by which naturally occurring organic materials are broken down by microorganisms such as bacteria and fungi into small particles which are not harmful to the environment.

Biodegradation is carried out by different agents such as UV radiation, light, wind, and water but the most effective agents of biodegradation are bacteria and fungi.

Biodegradation occurs in three distinct stages: biodeterioration, bio-fragmentation, and assimilation.

The biodeterioration process loosens up the structure of the organic substance. For instance, the cell wall of plants is weakened by light, wind, water, and UV radiation.

Bio-fragmentation involves the breakdown of organic matter into smaller, nontoxic particles by bacteria and fungi, releasing water and carbon dioxide in the process.

Assimilation is the last stage of biodegradation and it involves the microorganisms taking up the products of bio-fragmentation into their biological machinery to be used to make energy.

Biodegradation can either involve the microorganisms using oxygen, aerobic biodegradation or it can involve the microorganisms which do not use oxygen, anaerobic biodegradation.

What is keratin in feathers?

Keratin is a protein material that is found in the feathers of birds and the nails and hair of humans.

It is a tough molecule that can resist biodegradation from common protein degrading enzymes such as proteases. Keratin is effectively broken down by keratinase enzymes.

Keratin comprises almost 90% of feathers. It forms fibrous structures and is found in many organisms in nature. It is the third most abundant natural material after cellulose and chitin.

Keratin is made of cysteine amino acids. Keratin containing less than 10% cysteine is categorized as soft keratin while that with 10-14% is classified as hard keratin.

Hard keratin is found in hair, nails, hooves, claws, and wool. Soft keratin is found in the epidermal part of the skin.

Keratin forms polymers through hydrogen bonds, disulfide bonds, and hydrophobic interactions which result in compounds insoluble in water and organic solvents.

The polymers are tough and make keratin resistant to degradation by common proteases like trypsin and pepsin.

Keratin’s secondary structure contains alpha-helix and beta-sheet structures, and therefore, keratin can be classified as alpha keratin or beta keratin.

Both alpha and beta keratin is found in different concentrations in different molecules. Wool contains alpha keratin while feathers have both alpha and beta keratin.

Applications of keratin protein.

Keratin can be used as a source of nitrogen in many industrial applications.

The following are some of the applications of keratin.

  • Keratin from human hair can be used as a carrier for bone morphogenetic protein-2 in bone regeneration.
  • Keratin is used in wound healing applications.
  • Keratin from feathers and other organs can be converted into amino acids which are used to make animal feeds.
  • Keratin is used as a carbon and nitrogen source in Microbial culture.

What are the types of feathers?

There are two main categories of feathers; vaned feathers and down feathers.

Vaned feathers are found on the exterior of the body. Down feathers are found underneath the vaned feathers.

The two main categories can then be subdivided into smaller categories depending on the purposes.

  • Pennaceous feathers- these are types of vaned feathers. They are also called contour feathers.

They emanate from tracts and they cover the entire body.

  • filoplume feathers- these hairlike feathers are associated with the pennaceous feathers. They occur beneath the pennaceous feathers and grow from the same origin. They are found mostly in the bird’s head, neck, and trunk.

Filoplume feathers are absent in some types of birds.

  • Remiges feathers- these are also called flight feathers. They are found in the wings. They work the same way as the rectrices feathers found in the tail.
  • Flight feathers; remiges and rectrices are stiffened to work against the air in the downstroke.

Parts of feathers.

Different parts of feathers serve different purposes.

The different parts include:

Calamus/Quill.

This is the large hollow part of the shaft that attaches feathers to the bird’s skin or bones. The calamus contains no barbs.

Rachis.

This is also called the shaft of the feather. It is long and slender. It is the central part of the feather that holds the vanes.

Vane.

This is the part of the feather that grows from the rachis. 

Barb.

The barbs grow from the central shaft of the feather. It is like a feather within a feather because it is found within the vane. It lacks a shaft and has little barbs called the barbules.

Barbules. 

These are small barbs that grow from the central shaft of barbs. On one side, the barbules are smooth and on the other side, they have small hooks called barbicels that hook up the smooth barbules next to them.

Afterfeather.

These are the downy lower barbs. The afterfeather lacks barbicels. They are mainly used for warmth and not flight.

The applications of feathers.

There are different uses of feathers, either in industries, households, or cultural practices.

The different uses include the following:

  • Feathers are good at trapping heat and therefore they are used in beddings such as blankets, pillows, and mattresses.
  • They are used in filling winter clothes and outdoor beddings such as sleeping bags.
  • They are used in making quill pens.
  • They are used in decorations and the making of ornaments.
  • Feathers are used in fashion and military headdresses.
  • Feathers are used for fletching arrows.
  • Colorful feathers are used for decorating fishing lures.
  • Feathers are used in forensic studies to determine the geographic ancestry of birds.
  • Feathers are used in sampling non-destructive sampling pollutants.
  • Feathers are used in the culturing of microorganisms.
  • Feathers have been used in industries to make biodegradable polymers.
  • They are used as a source of enzymes.
  • Feather proteins have been used to make wood adhesives.
  • In South America, feathers are used to make brews for traditional medications.
  • In India, peacock feathers have been used to treat snake bites and infertility.
  • In Scotland, some people wear feathers on their bonnets to signify authority.
  • Feathers are used to make women’s hats and other headgear.

Are feathers eco-friendly?

Yes, feathers are eco-friendly because they are biodegradable and therefore they don’t accumulate in landfills and water bodies.

According to a study report, microorganisms that produce keratinase are capable of breaking down feathers.

However, the disposal of feathers in the environment might lead to landfills because feathers, as much as they are biodegradable, take a long time to fully break down because of the tough nature of keratin protein.

Biodegradation of feathers produces gases such as hydrogen sulfide, methane, and nitrous oxide; these gases are toxic to the human respiratory system, and therefore, feathers should be disposed of with a lot of care 

Feathers can also be burnt in an incinerator.

Conclusion.

This article has answered the question of feather biodegradability.

It has also addressed other areas such as:

  • Types of feathers.
  • Parts of feathers.
  • Applications of feathers.
  • Biodegradation of keratin protein in feathers.
  • Eco-friendliness of feathers.

For any questions or comments please use the comment section below.

Frequently Asked Questions (FAQs): is feather biodegradable?

Do feathers decompose?

Yes, feathers are decomposable. They are made from keratin which is a natural biomolecule that is broken down by the keratinase enzymes of bacteria and fungi.

Are feathers plastic?

No, feathers are biological molecules made from keratin protein, while plastics are synthetic materials obtained from petroleum.

Why do feathers not decompose?

Feathers do decompose. But the rate of decomposition can be slower when the population of keratinase-producing bacteria is low because non-keratinase-producing bacteria do not break down feathers.

Feathers are made from a tough keratin molecule that takes longer to break down than other biological molecules.

Citations.

Bonser, R.H.C.; Dawson, C. (1999). “The structural mechanical properties of down feathers and biomimicking natural insulation materials”. Journal of Materials Science Letters. 18 (21): 1769–1770. doi:10.1023/A:1006631328233

Lucas, Alfred M.; Stettenheim, Peter R. (1972). “Structure of feathers”. Avian Anatomy Integument. Vol. Part 1. Washington D.C.: US Department of Agriculture. pp. 235–276.

Prum, Richard O (1999). “Development and Evolutionary Origin of Feathers” (PDF). Journal of Experimental Zoology Part B: Molecular and Developmental Evolution. 285 (4): 291–306. doi:10.1002/(SICI)1097

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