Studies On Extraction And Application Of Crude Polysaccharide From Ulva Prolifera

Since mid-June 2008,there appeared large amounts of seaweed Ulva prolifera in the central yellow sea waters,then drift to the sea off Qingdao,it affect the sailing competition of the Olympic Games.Ulva prolifera is drugfree,but a large amounts of Ulva prolifera will block the light on the sea,and dead Ulva prolifera are also consumes oxygen,,some of the creatures will be seriously affected below sea level,it will not only lead to biological pollution,and also has a large negative impact on the landscape.The main ingredients of Ulva prolifera contain crude protein and crude ash,fats,polysaccharides,and fiber,and is rich in carbohydrates,protein and crude fiber,edible,medicinal and the production of animal feed and fertilizer.First of all,in order to explore the optimum conditions of extraction for Ulva prolifera polysaccharide.Research on alcohol sink water extraction technology of Ulva prolifera coarse polysaccharide in the algae body treatment,water extraction,sugar concentration and process cycle time with fresh Ulva prolifera collected from Jiangsu the East China Sea as raw materials,and extraction scheme obtained is fresh Ulva prolifera with 95% ethanol immersion after filtration,algae after drying according to liquid ratio of 1: 40(g/mL)soaked with distilled water,crushed tissue at 95 C for 15 min heating,cooling after filtration,the filtrate was concentrated to 95% moisture content after centrifugation supernatant,and 80% ethanol final concentration of alcohol precipitation after 24 h filter.Crude polysaccharide was obtained after precipitation.Under this condition,the fresh Ulva prolifera polysaccharide freeze-dried powder was 20.1%,the polysaccharide content of 51%.The effects of four kinds of seaweed polysaccharides on the growth and immunity of crucian carp were studied.The crucian carp(50g + 5g)reared for two days,were randomly divided into normal diet group,Ulva prolifera group,Porphyra yezoensis group,Sargassum horneri group,Porphyra haitanensis group for 4 replicates,accurate records its weight.After 60 d,it was injected with Aeromonas hydrophila for 107cfu/ml.After 24 h,the body weight of the fish was weighed,and the weight of the spleen was weighed,and detect the activities of ALP,AST,ALT,Lg by the blood of the fish.The experimental results show that the growth rate of Ulva prolifera group,Porphyra yezoensis group,Sargassum horneri group compared with normal diet group was increased,and the weight gain rate of Ulva prolifera group was best for 47.5%.The spleen coefficient of four groups was increased,Ulva prolifera group' and Porphyra yezoensis group' were better then others' for 23.8% and 27.7%.The number of colonies in four groups of medium compared with ordinary feed group reduced.Biochemical blood test results,the content of TP and Lg in the group of Ulva prolifera were higher than ordinary diet group.Finally,90 Oreochromis niloticus(50 + 5g)were divided into three groups: control group,Ulva prolifera polysaccharide group and Ulva prolifera powder group with three cylinder repeat breeding cycle for 6 weeks,every two weeks sampling,recorded the spleen coefficient,measured immune indexes and parameters.Experimental results show that the spleen coefficient of Ulva prolifera polysaccharide group and Ulva prolifera powder group were improved in a certain extent first four weeks,and Ulva prolifera polysaccharide group was the best at second weeks,it was 25.6% higher than the control group,the Ulva prolifera powder group was the highest at fourth weeks,it was 17% higher than the control group;The content CAT and MDA were increased and then decreased,they were highest at the fourth week,and Ulva prolifera group was the best.In conclusion,as is shown in Ulva prolifera polysaccharides extraction process was optimized and the energy loss in the process of extraction decreased,Ulva prolifera polysaccharides is suitable for batch preparation;Ulva prolifera polysaccharides were added in the feed can not only promote the growth of fish,but also improve the fish body immunity,confirm the effects of Ulva prolifera polysaccharides is superior to the effects of algae powder arides from Ulva prolifera algae powder is better than that of direct add.Therefore,we believe that Ulva prolifera polysaccharides is suitable for batch extraction,and it possess as feed additive to improve the ability of fish growth and immunity.