Immune stimulating abilities of β-glucans have received considerable attention and have been well studied in vertebrates. A wide range of studies demonstrated that β-1,3-glucans have a strong immune stimulating activity in a variety of vertebrates, such as mice, rats, chicken, pigs, sheep, cattle, horses, monkeys, and humans and it has been reported that glucans raise both the cellular and the humoral immunity. Also in aquaculture enterprises these compounds have been tested and have been successfully used to enhance resistance of fish and crustaceans against various bacterial infections. Glucans can be isolated from a variety of sources and comprise schizophyllan from fungi (Schizophyllum commune) [9,16], zymosan from yeast (Saccharomyces cerevisiae), paramylon from algae (Euglena gracilis), curdlan from bacteria (Alcaligenes faecalis), and pustulan from lichens (crustaceous) (Umbilicaria pustulata). They all have a (1,3)-β-D-glucopyranosyl linked backbone, but their branching frequency, degree of polymerization, molecular weight and solubility differ which play a role in glucan-associated biological activity.
Citation: Jaafar RM, Skov J, Kania PW, Buchmann K (2011) Dose Dependent Effects of Dietary Immunostimulants on Rainbow Trout Immune Parameters and Susceptibility to the Parasite Ichthyophthirius Multifiliis. J Aquac Res Development S3:001. doi: 10.4172/2155-9546.S3-001