Studies On Extracting Of Glycoprotein From Wastewater Of Sweet Potato Starch Production, Its Biological Activities And Structure

China is the biggest country of Sweet Potato production, most of Sweet Potato wasmanufactured into starch and a great deal of wastewater was produced during the SweetPotato starch production in China. The wastewater will pollute environment because thereare a large number of organics in it. Most of organics of wastewater are glycoprotein, whichhave excellent immunodulating and antitumor biological activity found by Japanesescientists. If the glycoprotein can be extracted from the waste water, not only the pollutingproblem can be resolved, but also can obtain a kind of biological activity product highappending value.Ultrafiltration was used for extracting glycoprotein from wastewater of Sweet Potatostarch production and the structure and biological activities of the glycoprotein were studiedin this paper. Major content of this paper as following:Technical route of extracting glycoprotein from wastewater of Sweet Potato starchproduction were confirmed as: wastewater was centrifuged twice (1,900 and 3,000rpm) andfiltrated with filtrating fabric (400 mesh), then concentrated with ultrafiltrator and vacuumconcentrator, then precipitated with 70% alcohol (final concentration), then freezed dryinginto powder.Optimum technical parameters and the retentive ratio and extracting ratio ofglycoprotein using hollow fabric ultrafiltrator was studied: pressure 0.17MPa, pH 6.5,temperature 20℃;volume concentration times after concentrating 100L wastewater was 7.7,glycoprotein concentration times was 5.25, retentive ratio of glycoprotein was 68.25%,extracting ratio of crude glycoprotein was 0.67%.Optimum technical parameters and the retentive ratio and extracting ratio ofglycoprotein using ceramic ultrafiltrator was studied: pressure 0.35MPa, pH 6.5,temperature 20℃, cross-flow velocity 2m/s;Volume concentration times after concentrating100L wastewater was 8.3, glycoprotein concentration time was 7.5, retentive ratio ofglycoprotein was 91.0%, extracting ration of crude glycoprotein was 0.88%.Although hollow ultrafiltrator can deal with large number of wastewater and use at alow cost, its membrane was polluted badly and difficult to clean, and lost of glycoproteinwas seriously compared with ceramic ultrafiltrator. So ceramic ultrafiltrator was moresuitable for concentrating glycoprotein from wastewater of Sweet Potato starch productionthan hollow fabric ultrafiltrator.A mathematic model of concentrating glycoprotein from wastewater of Sweet Potatostarch production using ceramic ultrafiltrator was described as following:26232. 43510.37780.9342390.91290.184910000ucPucJ =+ ? ?P?×+?Using this model and corresponding software, flux change can be predicted andoperating conditions also can be selected when flux confirmed.Glycoprotein of Sweet Potato has no acute toxicity certified by mice acute toxicityexperiment.Glycoprotein of Sweet Potato has excellent immunomodulating activity certified bycarbon clearance ratio of mice. Glycoprotein has the highest clearance index (4.52) at thedose of 50mg /kg.d. When used together with Cycolphosphamide, glycoprotein also canreduce damage of body by Cycolphosphamide.Glycoprotein of Sweet Potato has excellent antitumor activity certified by mice againstSarcoma 180 implanted tumor experiment. Glycoprotein has the highest tumor inhibitionrate (62%) at the dose of 50mg /kg.d. Glycoprotein also can enhance antitumor effect whenused together with Cycolphosphamide.Antitumor mechanism of glycoprotein of Sweet Potato was studied. Glycoproteinexerted its antitumor effect possibly through enhancing immunity of body, which proved bythe effects of proliferation of active splenocyte by ConA and S180 inhibition in vitroexperiment.Glycoprotein was separated and purified for screening high biological activitycomponents. Combining sulfate acid phase precipitation, ion-exchange, gel filtration,affinity chromatogram with the determining the effects of proliferation of active splenocyteby ConA and S180 inhibition in vitro experiment, Sp-3241 was got. Its purity was certified bygel filtration, PAGE and HPLC. The simulating index of no-active spleen lymphocyte invitro of the purified fraction SP-3241 was 1.727, which was enhanced 40.75% comparedwith index of crude glycoprotein, and the simulating index of active spleen lymphocyte invitro was to 1.965,which was enhanced 49.43% compared with index of crude glycoprotein.The structure of SP-3241 was studied, the result describe as following: SP-3241 is akind of glycoprotein;protein content is 91.60%;sugar content is 6.43%;it is rich in Asp(13.59%), Glu (7.75%) and Leu (7.27%);there were 4 kinds of sugar in the glycoproteinwith a ratio of glucose: galactose: rhamnose: arabinose 10.2:1.25:1:2.5;the relativemolecule weight of the glycoprotein determined by gel separation chromatogram and HPLCis 32359 and 32606Da respectively;sugar and protein is linked with O-link band and sugarlinked with Thr. There were 2 kinds of glycans in the glycoprotein (glycan-1 and glycan-2).Relative molecule weight of glycan-1 was 1725Da and there were 3 kinds of sugar in theglycan-1 with a ratio of rhamnose: glucose: galactose 1:10:1.2. Relative molecule weight ofglycan-1 was 468Da and there were 2 kinds of sugar in the glycan-2 with a ratio ofarabinose: glucose 1:2.05.Relationship between structure and biological activity was studied. The result was:there was no immunomodulating activity when using protein or sugar chain along;there wasimmunomodulating activity only when protein and sugar chains being linking together.