The effect of seaweed polysaccharides on immune activity and immune gene expression in shrimp penaeus monodon culture system

Abstract

An initial investigation was carried out to extract the polysaccharides such as fucoidan sodium alginate and alginic acid from brown seaweed s wightii the physicochemical and phytochemical characters of individual polysaccharides were studied the result of uv spectral ft ir 13c and 1h nmr analysis indicated the presence of carbon and anomeric proton of and#945; l fucose 1 6 and#946; d linked galacton and#946; d manuronic acid and sulphate group in purified fucoidan and gluronic acid and mannuronic acid in sodium alginate and alginic acid respectively the antibacterial activity of all the three polysaccharides was screened against vibrio pathogens the fucoidan sodium alginate powder sodium alginate beads and alginic acid were enriched with artemia nauplii at four different concentrations 100 200 300 and 400mg l for 12h and were fed to p monodon postlarvae for 20 days and the growth performance was studied then the p monodon postlarvae were challenged with wssv and v parahaemolyticus individually and the reduction in mortality percentage of experimental groups over control group was recorded with good result in experimental groups against both pathogens the wssv infection in the challenged shrimp was determined through nested pcr analysis and confirmed the concentration dependent variation heavy 910bp to low 296bp the v parahaemolyticus load was increased from 10th to 30th days of challenge test in control group however it was decreased positively in the experimental groups further the polysaccharides were supplemented individually