Studies On The Synthesis Of Trehalose From Corn Amylose By Enzymatic Method

Trehalose is a non-reducing disaccharide by a a,l-1 glucosidic linkage that bindsthe two glucose molecules. Trehalose inside orpanism cell will rise promptly to protect itSelfwhen it is at different constrained conditions as hunger,dryhightemperatUr,freezing,radiation,h Permeation pressure and POisonous reagent.Thus trehaloseis paid c1ose attention.Trehalose eXterior organism can also act on oI'ganism and biologicmolecule to protect them distinctively .Therefore trehalose is widely used inbi o l ogy pharn aeeuti cals, fbodstuff cosm eti c and argh cu ltUre. A t presenL it is prim ari l y used tOsynthesize trehalose that tranSform amylose with low coSt of manufacture and high ovetallrecovery rate .This stUdy mainly discussed synthesis of halose from amylose throughcombined action of microoganism by intramloecular tranSglycosylation.Scain that producederwme and itS cultUred proPethes,character ofthehalose creataSe and production oftrehalosewere detailed StUdied.The start strain was treded with UV-ray irradiation to obndn a strain of ST4l2 with highyield trehalose.Staln was inoculated dbectly on solid medium and irradiated imrnediatelyunder ultraviolet lamp.Producing CaPaCityits of ST4l2 was increased 7tAnes higher than theoriginal sthen with stability. Modality charaCter, chendcal classificationy, physiology andbiochemiStry characteristic of ST4l2-strain were identified.The result showed that this mein isStraptomeyCes lu!egheus.The cultured propertier of ST4l2-Strain were discussed.The resultS shOwed that: (l )Maltose was the oPtjmum wtn source,pePone and be f endon were the oPtimumnitrOgen source, K2HPO and MgSO4 7H2O were the oPtiInum inowic. (2 ) The formula ofculwt medium boUgh ortboonal exPeriInent Asgh was ope as:the 1 -- .5 %,be f ndOn0Th.K2HPO0 .2% and MgSO4 7H2oc. 05 %. (3 ) TheOPboam twon conditions werempreture3l C .PH7.0,CaPaCity 100ml per 50OrnltriWlar bottle .boention time 144 home.The proPerties oftrehalose cds were considerd SyStematically.The resultS indicaed2002^6^that:If the concentration of liquefied solution of amylose and liquefied time were 10% and SOminutes relatively, ( 1 ) the enzyme exhibited an optimum tempreture of 40*C and the optimum pH value of 7.0 . (2) the enzyme activity was increased by addition of Ca2+ and Mn2+ ,but was inhibited 96%,69%,77% and 79% enzyme activity by Cu2+,EDTA,Fe3+ and Fe2+ , relatively. ( 3 ) Substrate specifixity of trehalose creatase had been verified by experiment, which eliminated possibility of glucose and maltose as its substrate. (4) the conserving stability of crude enzyme solution was inferior.lt is unsuitble to conserve enzyme solution for long time at4"C.It was investigated of the possibility of using ultrafiltration technique in the concentration process of trehalose-creatase.The regenerated cellulose ultrafiltration membrane of one ten thousand dalton were selected to concentrate trehalose-creatase liquor.The time of concentration,yield of concentration and ratio of rejection were determined.And observe the flux,too.The experimental results indicated that molecular weight 10,000d is feasible under the optimum conditions (pressure of 0.04Mpa,tempreture of 30?0 "C) , furthermore yield of concentration could surpass 60%.It was found that using ultrafiltration not only would protect the activities of enzyme.but also could remove low molecular impureties partly effectively.Studies on reaction condition for production of trehalose were made systematically. Above all,it was determined that concentration of liquefied solution of amylose and liquefied time were 1 0% and 30minutes relatively by single factor analyse.lt was optimized by orthogonal experiment design for another five influent factors such as tempreture,time,concentration of buffer and pH and the mount of enzyme.The experimental results indicated that the optium conditions were tempreture 40 癈 , time 36hours,concentration of bufferO.lM, pH 7.0 and the mount of enzyme27 U/g amylose followed with 28. 1 4% tr...