Studies On Selection And Cultivation Of High Maltooli-gasaccharides Producing Rhizopus In Distillers' Yeast And Its' Major Degrading Products From Starch

Rhizopus is mainly used in fermentation for its enrichment amylases.In the glutinous rice wine it is the main microbe of saccharification. To enhance the functional oligosaccharides in the glutinous rice wine.This experiment studied on the amylases of Rhizopus and the relation with the malt-ooligasaccharides content,selected and cultivated the strain that highly yield maltooligosaccharides,studied on the characters of the glucoses. This thesis deals with five parts:1 This experiment made a selection and purification of Rhizopus from Distillers' yeast.We gained four strains Rhizopus RN-1, Rhizopus RA-1, Rhizopus RS-1 and Rhizopus RQ-1 which had oligosacchridase activity, these four strains produce a -amylase and glucoamylase better than traditional Q303.The glutinous rice wine made with Rhizopus RA-1 has the most maltooligosaccharides.2 We gained Rhizopus RA-UV4 with 403.75 higher oligosacchridase ,486.2% higher α -amylase, 567.8% higher glucoamylase than the original one after mutagenesis by ultraviolet and NaNO₂ on Rhizopus RA-1.3 Amylases of Rhizopus RA- UV4 are separated and purified by (NH₄)₂SO₄ fractional precipitation,DEAE-cellulose ion-exchange chromatography and gel G-100 filtration. It was determined by PAGE, the amylase shows glucoamylase line and two a -amylase lines, the three molecular weights detemined by SDS-PAGE are about 78 kD,48 kD and 50 kD.4 We made glutinous rice wine with Rhizopus RA- UV4.After the gel G-100 column we found glucose, dissaccharide, triasaccharide.The glutinous rice wine can yield total sugar 355.43 g/k g(rice),reducing sugar 305.21 g/kg(rice),oligosaccharides value 14.13%, total oligosaccharides 50.21 g/kg(rice), 105.9% higher than the original one triasaccharides 25.43 g/kg(rice), 119.1 % higher than the original one.