Abstract
Chitin, a polymer of N-acetyl-D-glucosamine (GlcNAc), functions as a major structural component in crustaceans, insects and fungi and is the second most abundant polysaccharide in the nature. Although these chitin-containing organisms have been suggested as novel animal feed resources, chitin has long been considered as indigestible fibers in the animal body. Recently, we reported that acidic chitinase (Chia) is a protease-resistant major glycosidase in mouse gastrointestinal tract (GIT) and that it digests chitin in the mouse stomach. However, the physiological role of Chia in other animals including poultry remains unknown. Here, we report that Chia can function as a digestive enzyme that breaks down chitin-containing organisms in chicken GIT. Chia mRNA is predominantly expressed in the glandular stomach tissue in normal chicken. We also show that chicken Chia has a robust chitinolytic activity at pH 2.0 and is highly resistant to proteolysis by pepsin and trypsin/chymotrypsin under conditions mimicking GIT. Chia degraded shells of mealworm larvae in the presence of digestive proteases and produced (GlcNAc)2. Thus, functional similarity of chicken Chia with the mouse enzyme suggests that chitin-containing organisms can be used for alternative poultry diets not only as whole edible resources but also as enhancers of their nutritional value.
Highlights
The world’s consumption of meat is increasing with growing population
Chia mRNA is highly expressed in glandular stomach in chicken
We found that Chia mRNA was predominantly expressed in glandular stomach, followed by spleen, gizzard, liver and kidney with gizzard having 50 times lower expression than glandular stomach (Fig. 1a)
Summary
The world’s consumption of meat is increasing with growing population This process requires a continuous increase in animal feed production in the limited source of land and water[1]. Insects and fungi are ubiquitous organisms that have recently become attractive as potential novel animal feed resources because they are rich in protein[6], high feed conversion efficiency[2], and lower production of greenhouse gas and NH3 emissions than livestock[7]. As animal feed, these organisms are more acceptable for many consumers rather than ingesting them directly. Genetic variants of Chia are associated with asthma in humans[25,26,27,28]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
