Fungi and insects contain chitin, which is about 6% nitrogen. Can an animal - like me - make use of this as a nitrogen source to build proteins?

Are there any animals that can do this?

Are there other uses an animal can put Nitrogen from this specific source to?


2 Answers 2


This article suggests a certain amount of chitin digestion is possible.


I can't quantitatively say how much of any of the myriad potential chitin sources (fungal, crustacean or other arthropods) would be digested within a 'normal' time frame in the human digestive system. That work should probably be undertaken, though.

  • $\begingroup$ You might summarize the key points of the article, including the fact that humans do have chitinase genes. I would cut your last line, which is a matter of opinion on research priorities. It's not the sort of work that I would fund. $\endgroup$
    – David
    Jul 12, 2017 at 9:08

The first answer is that humans cannot. Chitin is a major component of the exoskeleton of insects and other arthropods, the cell wall of fungi and bacteria, the perisarco of hydroids and is also present in the epidermal cuticle or other surface structures of many other invertebrates. After cellulose, chitin is the most abundant naturally occurring biopolymer.

Chitin is a polysaccharide consisting of multiple units of N-acetylglucosamine (N-acetyl-D-glucos-2-amine) linked together with a bond-type β-1, 4, of the same glucose units forming the cellulose. Therefore, the the chitin can be regarded as a cellulose in which the hydroxyl group on each monomer has been replaced a group of acetilammina.

Pepsin in the stomach cleaves peptide bonds that bind together the amino acids of proteins, thus forming small peptides and amino fragments.

From the organoleptic point of view, chitin is considered a fiber, like cellulose and chitosans, suggesting it is indigestible.

Some herbivores, such as goats and some ruminants can digest cellulose, breaking them down long chains of polysaccharides. Similarly, echinoderms can eat shellfish, sea urchins and mussels and digest chitin, breaking mechanically only ones with hard shells.

However, hydrogen bonds between adjacent polymer guarantee the substance a remarkable hardness. This feature, combined with its flexibility and the fact that it is degradable by endogenous enzymes, chitin is an excellent material for the production of wires for surgical sutures, bandages and also synthetic leather. Chitin also has the unusual property of accelerating the healing of wounds in humans, closely related to chitosan (a more water-soluble derivative of chitin) and to the immune system of plants and animals.


Yes, @mart. Echinoderms use chitin for producing proteins, similar to how herbivores use plant cell walls, which consist mainly of polysaccharides (non-nitrogen compounds), to produce the proteins (nitrogen-containing compounds), that serve us also (since we are not able to digest the grass).

  • $\begingroup$ More sparing use of formatting might make your answer easier to read $\endgroup$
    – Rory M
    Apr 17, 2013 at 13:50
  • $\begingroup$ Counted my bad English, I will very gratefull if you do it :) $\endgroup$ Apr 17, 2013 at 14:07
  • $\begingroup$ Those animals that can digest chitin, do they use the contained N for protein building or other purposes? $\endgroup$
    – mart
    Apr 17, 2013 at 14:23
  • $\begingroup$ This answer should not have been accepted in my opinion. It contains a ragbag of mainly irrelevant information and then it gets its key fact wrong. Humans have the potential to digest chitin as they have the genes for chitinase. The doubtful assertion that the the product of chitin digestion (Nacetyl glucosamine) is used for protein synthesis (i.e. converted to amino acids) rather than used for the synthesis of polysaccharides is not backed by any references or links so we cannot judge whether it is correct. $\endgroup$
    – David
    Jul 12, 2017 at 9:05

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