ABSTRACT
Seaweeds contain significant quantities of lipids, protein, vitamins and minerals. Aquavac Ergosan contains 1% alginic acid extracted from two brown seaweeds, Laminaria digitata and Ascophyllum nodosum. Both in vivo and in-vitro researches have mainly been focused on the effect of Ergosan on fish growth, survival rate, reproductive performance and innate immunity in blood and epidermal mucus. Despite numerous studies on the effects of Ergosan on immune system of aquatic animals and evaluation of seaweeds in proximate analysis, there is no data available on proximate analysis of irradiated Ergosan extract [alginic acid]. Therefore, the aim of this study was to assess the effect of on different groups of irradiated alginic acid [10, 20, 30, 40 and 50 KGy] for analyzing proximate composition. Alginic acid was prepared from the sonicated Ergosan extract. The Alginic acid extracted from Ergosan was irradiated with a gamma cell. The protein and lipid content and Moisture and ash were recorded. Statistical analysis showed no significant differences among all of groups in terms of protein, lipid, ash and moisture. Radiation processing is a very convenient tool for imparting desirable effects in polymeric materials. The polysaccharide degradation by gamma or ultraviolet irradiation is free of initiators. High energy radiation technique can be effectively used to decrease the molecular weight of different polysaccharides such as alginate and Chitosan. Based on the results of this study, gamma irradiation of alginic acid as natural polysaccharide had no effect on crude protein, crude lipid, moisture and ash
ABSTRACT
Background: Vibrio paraheamoloyticus is one the causative agents of vibriosis with high mortality in farmed fish and shrimp and under predisposing conditions
Objectives: This study was aimed to assess the effect of gamma irradiation on the inactivation of V. paraheamoloyticus under fresh and freeze-dried conditions
Methods: Vials of 0.5 ml fresh culture of the bacterial suspensions at 1.5[asterisk]10[10] cfu/ml were subjected to 1, 1.5,2, 2.5, 3 and 4 KGy. Also, vials of 0.5 ml freeze-dried culture of the bacterial suspensions at 1.5 x 1010 cfu/ml were subjected to 2, 4, 7 and 8 KGy. The bacterial growth behavior was then evaluated on fresh medium
Results: The obtained results showed that the minimum doses of 4 and 10 KGy were sufficient for the inactivation of fresh and freeze-dried bacteria, respectively
Conclusions: The result of this study shows that inactivation of V. paraheamolyicus in fresh culture condition requires below half- dosage of gamma ray required for the inactivation of the freeze- dried of bacterial cells
ABSTRACT
The approaches chosen for control of Outbreaks of infectious diseases in Aquatic farming industry include improvement of environmental conditions, stocking of specific pathogen free [SPF] brood stockings, and application of vaccines and immunostimulants. Despite numerous studies on the effects of Ergosan on immune system of aquatic animals, there is no data available on antioxidant activities of Ergosan. The aim of the present study was to investigate and evaluate the radical scavenging activities of Ergosan extract by DPPH [1, 1-diphenyl-2-picrylhydrazyl] free radical scavenging assay, and the possible effects of gamma irradiation on its assumed radical scavenging activities. Ergosan was irradiated with gamma rays [10, 20, 30, 40 and 50 kGy], and their structural changes and antioxidant activities were investigated by UV absorbanceand DPPH [1,1-diphenyl-2-picrylhydrazyl] assays, respectively. The gamma irradiation decreased the average pH of irradiated Ergosan, and UV spectra of irradiated product showed increase in the number of carboxyl groups and double bonds. Our results showed that 30 kGy irradiated Ergosan suspension had significant higher level of antioxidant activity in comparison with non-irradiated Ergosan [P<0.05]. Also, the reducing power values of 30 and 50 kGy irradiated Ergosan were higher than that of nonirradiated [P<0.05] and the other doses of irradiation couldn't make any significant difference in reducing power of Ergosan. Results indicate that the 30 kGy irradiated Ergosan might be an appropriate candidate for the use in aquatic animal diets as a natural antioxidant agent besides its immunostimulant role