Chitinase and Insect Meal in Aquaculture Nutrition: A Comprehensive Overview of the Latest Achievements

Abstract

The aquaculture industry is looking for sustainable alternatives to conventional fish meals in fish feed, and insect-based meals are proving to be a promising solution. These meals are nutritionally optimal as they have a high protein content and an ideal amino acid profile. However, the presence of chitin, a component of the insect exoskeleton in these meals presents both an opportunity and a challenge. Chitosan, a derivative of chitin, is known to improve the physiological functions of fish, including growth, immunity, and disease resistance. While chitin and its derivative chitosan offer several physiological benefits, their presence can affect the digestibility of feed in some fish species, making the inclusion of insect-based meals in aquafeeds complex. While studies suggest positive effects, some problems, such as reduced growth rates in certain species, emphasize the need for further research on chitin digestion in fish. Chitinase, an enzyme that breaks down chitin, is being investigated as a potential solution to improve the nutritional value of insect meals in aquafeed. This review provides a comprehensive analysis of the applications, benefits, and challenges of using chitinase in aquaculture, highlighting the enzyme’s role in improving feed digestibility, disease control, and environmental sustainability. Extensive research is required to fully understand the potential of chitinase enzymes in aquaculture and to optimize their applications in this dynamic field. Overall, this review provides insight into the evolving landscape of insect-based meals and the applications of chitinase enzymes within sustainable aquaculture practices.

The Replacement of Fish Meal with Poultry By-Product Meal and Insect Exuviae: Effects on Growth Performance, Gut Health and Microbiota of the European Seabass, Dicentrarchus labrax

“…Insect meal and especially exuviae are considered as valuable sources of chitin. Chitin is an insoluble fiber consisting of β-1,4-poly-N-acetyl-D-glucosamine and can be used as a substrate for bacterial fermentations, leading to the production of acetate, propionate, and butyrate as the main end products with positive effects on gut health [22,48]. In the present study, the highest amount of propionate and butyrate was found in the gut of seabass fed with exuviae meal.…”

“…It can produce antimicrobial and volatile organic compounds and degrade non-starch polysaccharides; last but not least, the bacteria of this genus have chitinolytic activity [51,52,[57][58][59]. The presence of chitinolytic bacteria is particularly important when feeding insect-derived ingredients to fish as bacterial chitinases help to improve the digestibility of the feed [48]. In rainbow trout, on the other hand, the addition of 1.6% pupal exuviae meal of H. illucens to a diet containing 20% FM resulted an enrichment of various bacteria genera, such as Corynebacterium, Bacillus, Facklamia, and Brevibacterium.…”