Study On Polysaccharide-degrading Enzymes From Monascus

It is rare in the report that Monascus can produce xylanase and raw starch enzyme. Xylanase is the main raw material which is applied in papermaking,food,feed,energy, pharmaceuticals and environmental protection.By hydrolyzing raw starch,the raw starch enzyme can save the energy.The main research contents:In this paper,Eight strains of Monascus which can produce xylanase were isolated by Kongo red dye.It was concluded that the Monascus 533 and the Monascus M2 can produce amylase and raw starch enzyme.It was inspected that Monascus 533 and Monascus M2 can produce amylases by PEAE.The optimal fermentation conditions were determined by orthogonal experiments,the results as follows:incubation time,6 days;fermentation temperature,36℃;the initial pH,4.5; dry medium:water=1:1.2.1t was discovered that the incubation time was the greatest influence element in production of xylanase.The raw starch enzyme was purified by 50%-70% ammonium sulfate precipitation, SephadexG-25,DEAE Sepharose fast flow column Chromatographies and Sephacryl S-200. The purity of the sample showed two protein bands which are a molecular weight of about 60.0 kDa by SDS-PAGE.It was proved that the sample contains raw starch enzymes.The optimal temperature and pH value for xylanase activity were 47℃and 5.5, respectively.The xylanase was stable in pH value 4.5-5.5. The activity was activated by Ca2+,Na+ and Tween80,while inactivated by Mn2+and SDS.The xylanase can restrain 65% activity under 4℃.Km and Vmaxof the xylanase were 3.08g/ml and 0.4947u/min repectively.It can decompose purple potato,rice straw powder,bran and sawdust.The optimal temperature and pH value for raw starch enzyme activity were 45℃and 5 respectively.The raw starch enzyme was stable in pH value 3-7.Km and Vmaxof the raw starch enzyme were 6.37g/ml and 3.85u/min repectively.