杏鲍菇胞外多糖液体发酵条件优化论文-毕业论文.doc

杏鲍菇胞外多糖液体发酵条件优化摘要杏鲍菇是一种品质优良的名贵珍稀食用菌，有很高的营养和食用价值，其营养成分丰富，多糖含量在食用菌中位于前列。相关研究已经证明杏鲍菇多糖具有降血脂等生物功能，因此通过液体发酵获得较高的杏鲍菇胞外多糖产量具有实际意义。本研究以杏鲍菇菌丝体为实验对象，通过五个单因子实验确定杏鲍菇菌丝体发酵获得胞外多糖产量最高的培养基组分。实验结果显示最佳碳源、氮源、无机离子、pH值和培养时间，依次分别为半乳糖、蛋白胨、磷酸二氢钾、6.0和9天。在单因子实验的基础上，本文通过四因素三水平的正交实验得到杏鲍菇胞外多糖产率最高的培养基配方应为半乳糖30g/L，蛋白胨5g/L，磷酸二氢钾3g/L且初始pH调节至6.0，按照上述条件可得到的杏鲍菇胞外多糖得率为5.92±0.84g/L。关键词杏鲍菇；胞外多糖；培养基优化AbstractPleurotuseryngiiisakindofrareandpreciousfunguswhichhashighnutritionalandediblevalue.Furthermore,itisrichinpolysaccharidecontent,whichhasbeenprovedrecentlytohavelipid-loweringpowerinblood.Therefore,thestudyoffluidmediumoptimizationofP.eryngiifortheimprovementoftheproductionofextracellularpolysaccharideisfullofpracticalsignificance.Inthisstudy,wetreatmyceliumasexperimentalsubject,andcarryoutfivesinglefactorexperimentstofindoutthebestmediumcomponents,whicharegalactoseasthebestcarbonsource,peptoneasthebestnitrogensource,potassiumdihydrogenphosphateasthebestinorganicions,6.0asthemostsuitablepHvalueand9daysastheincubationtime.Basedonthesinglefactorexperiments,weproceedtoanorthogonalexperimentaldesignwhichhasfourfactorsandthreelevelsofeachfactor,andthroughthisexperimentwefindouttheoptimalmediumforthelargestproductionofP.eryngiiextracellularpolysaccharide,whichisgalactose30g/L,peptone5g/L,potassiumdihydrogenphosphate3g/LandtheinitialpHvalueshouldbeadjustedto6.0.Undersuchconditions,theratioofproductionofP.eryngiiextracellularpolysaccharideis5.92±0.84gperliteroffermentationliquor.KeywordsPleurotuseryngii；extracellularpolysaccharides；fluidmediumoptimization目录TOC\o"1-3"\u1引言PAGEREF_Toc408412材料与方法PAGEREF_Toc1956632.1主要材料与试剂PAGEREF_Toc1572932.1.1生物材料PAGEREF_Toc1613232.1.2试剂PAGEREF_Toc938232.1.3培养基PAGEREF_Toc1539232.2主要设备PAGEREF_Toc1798832.3试验方法PAGEREF_Toc3098932.3.1菌种活化PAGEREF_Toc2567032.3.2碳源单因子实验PAGEREF_Toc2926242.3.3氮源单因子实验PAGEREF_Toc250642.3.4无机离子单因子实验PAGEREF_Toc1140542.3.5pH值单因子实验PAGEREF_Toc1607842.3.6培养时间单因子实验PAGEREF_Toc1379242.3.7液体发酵培养条件正交试验PAGEREF_Toc1199142.3