【作者】 杨抚林；

【导师】 邓放明；

【作者基本信息】 湖南农业大学 ， 食品科学， 2005， 硕士

【摘要】 冠突散囊菌(Eurotium cristatum)是茯砖茶生产过程中的优势菌，是形成茯砖茶独特品质的主要因素。本研究从茯砖茶中分离纯化出冠突散囊菌，对其菌落、菌体形态特征进行了观察；探索不同培养基组分及发酵条件对冠突散囊菌菌丝体生长的影响，确定了冠突散囊菌最佳液体培养基和培养条件；采用机械搅拌发酵罐对冠突散囊菌进行液体深层发酵，研究了其发酵过程中茶多酚、儿茶素、茶色素、氨基酸、pH值和蔗糖含量的变化动态，并测定冠突散囊菌菌丝体随发酵时间的变化情况，绘制出冠突散囊菌生长曲线；采用体外模拟胃液和模拟肠液，研究了冠突散囊菌发酵液对α-淀粉酶、胃蛋白酶、胰蛋白酶和脂肪酶活力的影响。其主要结果如下：1．从茯砖茶中分离纯化出冠突散囊菌，接种到PDA培养基上培养。培养前期，菌落周边呈白色或淡黄色，内部颜色稍深；培养后期，菌落周边呈黄色，内部呈褐色。冠突散囊菌菌落由子囊果与菌丝组成。菌丝呈白色，直径8～10μm；子囊果呈球形或近球形，黄色，直径150～200μm，子囊果中含有许多子囊，呈球形至近球形，直径5μm左右，子囊果生长到一定时期就会破裂释放子囊。2．冠突散囊菌深层发酵适宜的培养基组成为：黑茶0.8％、蔗糖6％；其最适培养条件为：培养温度30℃，转速120r／min，起始pH值5.5，接种量孢子悬液1％(孢子浓度为5.0～6.0×10~8个／ml)，发酵周期84h。在优化的试验条件下，进行摇瓶发酵，冠突散囊菌菌丝体生物量(以菌丝体干重表示)达0.3992mg／100ml。3．冠突散囊菌生长曲线呈现迟滞期(0～48h)、对数生长期(48～84h)和稳定期(84～120h)，第84h菌丝干重达到最大值0.3754g／100ml。4．冠突散囊菌发酵过程中，黑茶发酵液pH值的变化规律为前期下降，中期回升，后期稳定。具体变化情况是0～36h下降缓慢，pH值从5.51下降到4.76；36～48h下降较快，pH值从4.76下降到4.05；在48～96hpH值开始回升，从4.05回升到5.04；96h～120hpH值趋于稳定，为5.00左右。5．冠突散囊菌发酵过程中，黑茶发酵液的茶多酚和儿茶素含量急剧下降，茶色素含量不断升高。茶多酚的含量从发酵初期的123.726mg/100ml降低到48.935mg／100ml；儿茶素总量降低了73.68％；发酵液中TF的含量很少，仅为1.52mg/100ml，发酵的前24h有微量增加，以后逐渐下降，到96h时不能检出TF；TR的含量在发酵的前84h一直是增加的，发酵前24h增加幅度稍大，到96h时TR含量开始下降；TB的含量在发酵过程中一直是增加的，前期增加缓慢，72h后增加较快。(TF+TR)／TB呈先升后降的趋势。6．冠突散囊菌发酵过程中，黑茶发酵液的氨基酸总量呈下降趋势。发酵84h时，氨基酸含量从最初8.340mg/100ml下降到1.756mg/100ml，下降了78.9％。7．采用体外模拟胃液，冠突散囊菌黑茶发酵液对胃蛋白酶活性有促进作用，但对脂肪酶活性有抑制作用，发酵72h的发酵液可提高胃蛋白酶活性3.98倍，降低脂肪酶活性46％。在模拟肠液中，发酵72h的发酵液可提高α-淀粉酶活性1.59倍，提高胰蛋白酶活性3.45倍，降低脂肪酶活性14％。更多还原

【Abstract】 In this study, Eurotium cristatum were isolated and purified from Fuzhuan bricktea. Its microflora and individual shape characteristics were observed. Thesubmerged fermentation conditions of Eurotium cristatum were studied with shakeflask culture method. The optimal content of liquid culture medium and conditions ofEurotium cristatum were confirmed too. Adopt mechanical mixing fermenter, thevariations of main components of fermentative liquor during the submergedfermentation of Eurotium cristatum were investigated. In addition, the effects ofEurotium cristatum fermented solution on amylase, proteinase and lipase activitieswere studied. The results were concluded as follow:1. Eurotium cristatum isolated and purified from Fuzhuan brick tea, was inoculated onPDA culture medium. In the earlier stage of cultivation, the color of colonyperimeter is white or yellow and the inside color is slightly dark. In the later stage,colony perimeter is yellow and inside is brown. Eurotium cristatum colony ismade up of mycelium and plectomycete. The mycelium is white. Theplectomycete is yellow and like or nearly like a ball. Its diameter is 150-200μm.Plectomycete contain a lot of sporangium, which is like or nearly like a ball andits diameter is about 5μm. Plectomycete will split open and release sporangiumin a regular period.2. The optimal composition and content of culture medium are as follows: sucrose6%, dark green tea 0.8%. The optimal cultivation conditions of Eurotium cristatumthrough orthogonal designs were initial pH 5.5, Rotational speed 120r/min, culturetemperature 30℃, fermentation time 84h and inoculating amount 1%. Under the optimal conditions, the dry weight of mycelium reached 0.3992mg/100mlfermented solution.3. The growing curve of Eurotium cristatum is made up of lag phase (0～48h), thelogarithm growth phase (48～84 hours) and the stationary phase (84～120 hours).After fermented 84h, the dry weight of mycelium reached 0.3754mg/100mlfermented solution.4. PH value of the fermented liquid drops generally during the fermentation. It dropsslowly in 0～36 hours, from 5.51 to 4.76. PH value drops fast in 36～48 hours,from 4.76 to 4.05. PH value begins to go up in 48～96 hours, from 4.05 to 5.04. PHvalue tends towards stability from 96 hours to 120 hours, and it is about 5.00.5. The contents of tea polyphenols and catechins decrease fast and the content of teapigments is rising constantly during the fermentation. The content of teapolyphenols decreases to 48.935mg/100ml from 123.726mg/100ml and thecontent of catechins reduces by 73.68%. There is a little content of TF Infermentation solution, and it increases a little in initial 24 hours and decreasesgradually afterwards. TF can’t be examined out at the 96th hour. In the first 84hours the content of TR increases, then it turns to decrease gradually. The contentof TB increases during the fermentation, increases slowly in earlier stage,increased very fast after 72 hours.6. The content of Amino acid during the fermentation changed from 8.340mg/100mlto 1.756mg/100ml, decreases by 78.9%.7. In simulated gastric, fluid Eurotium cristatum fermented solution could promotethe activities of gastric proteinase and inhibit the activity of lipase, the activities ofgastric proteinase increase to 1.59 times and the activity of lipase reduced by46% compared with the control. In simulated intestinal fluid, the activities ofgastric proteinase andα-amylase increase to 3.45 and 3.98 times compared withthe control, but activity of lipase reduced by 14%.更多还原