Analysis On Nutritional Composition Of Gracilaria Lemaneiformis And Studies On Isolation, Purification And Physiological Functions Of Phycoerythrin

In this paper the main nutritional composition of the Gracilaria lemaneiformis collected from the sea area around Nan'ao county was analyzed. Besides, some of its harmful metals was also been analyzed. The results showed that the content of the crude protein, crude fat, crude fiber, total carbohydrate, polysaccharide and ash are 21,0.46,6.25,43.76,32.1,28.82% respectively. The contents of Hg, Pb are all below the national secure and sanitational standard of foods except of As. Compared with other algas, It is rich in vitamin C. The content is117 mg/kg. It revealed that the Gracilaria lemaneiformis is an useful edible seaweed with high nutritional values. It showed high development and application value.Different methods were tested to extract and purify phycobiliproteins from the red alga Gracilaria lemaneiformis. It is proven that tissue- trituration method has the highest efficiency for cell fragmentation compared with other methods, and ammonium sulfate at saturation degree of 60% had much better salting-out effect, and chromatographing the crude phycobiliproteins by both Hydroxyapatite and Sephadex G-100 column had the best purification effect. The phycobiliprotein's properties were investigated by methods of electrophoresis, absorption spectrum and fluorescence spectrum. The results show that the two molecular weights of subunits of the phycoerythrins are 18000Da and 24000Da, absorption maximum at 498nm, 540nm and 566nm, belongs to R-PE type I , the fluorescent emission peaks of 436nm and 540nm were both at 580nm.The scavenging activities of the crude phycobiliproteins and the PE on ·OH of Fenton reaction and O2 ·~- of Luminol reaction were studied. The results showed that the crude phycobiliproteins and the PE both could scavenge free radicals, but their abilities were different. In this paper we also did a rice experiment to investigate the antioxidative effect of the phycoerithrins in body. The methods of spectrophotometry and pyrogallol autoxidation were used to test LPO content in blood serum and SOD content in erythrocyte. The results showed that the PE could obviously decrease the content of serum lipoperoxide, and also increase the activity of superoxide dismutase of erythrocytes. It showed that the PE has an antioxidative effect, suggesting that it hasantiaging function.The inhibitory effect of the crude phycoerythrin(PE) on the frequency of PCE micronucleus induced by CP and its anti-tumor effect on mice bearing Si8o sarcoma were also studied. The result showed that the PE could decrease significantly the frequency of PCE micronucleus with dose-effect relationship, and also an obvious antitumor effect with an inhibitory rate 44%.