The effect of polysaccharide from Padina boergesenii on Aeromonas hydrophila resistance and growth, biochemical, digestive enzymes, non-specific immune response in Oreochromisniloticus

Abstract

The present study was designed to investigate the sulfated polysaccharide isolated from Padina boergesenii influenced immunological mechanisms and disease resistance in Nile tilapia Oreochromis niloticus after being infected with Aeromonas hydrophila. FTIR, NMR and HPLC were used to characterize the isolated Sulphated polysaccharide extracted from P. boergesenii. The antioxidant properties of the isolated polysaccharide were investigated. The experimental group was divided into five groups (T1-T5) and experimental groups (T2-T5) fed with polysaccharides at concentrations of 0.5%, 1.5%, 2.5%, and 3.5%. The Group T1 serves as a control, and the diet contains no polysaccharides. The 45-day study period involved the examination of O. niloticus haematological, immunological, biochemical, digestive enzymes, antioxidant, and growth traits. Growth, biochemical components, digestive enzymes, haematological, immunological, and antioxidant levels were significantly higher in Experiment T4 (2.5%) compared to the other experimental groups. The experimental groups were infected with A. hydrophila after the feeding trial. Our results predict that the feeding polysaccharide-rich diets may help in growth of the fish and develop their biochemical, digestive enzymes, non-specific immune response, and disease resistance in O. niloticus.