营养保健甘薯汁制备工艺的优化

目的:优化营养保健甘薯汁的制备工艺。方法:本研究以甘薯为原料,在加酶量、作用时间、反应温度、pH及底物浓度五个单因素试验的基础上采用响应面分析法,以甘薯浆中还原糖量为评价指标,对耐高温α-淀粉酶酶解甘薯浆中淀粉的最佳工艺进行了研究,并利用统计学方法建立了耐高温α-淀粉酶酶解甘薯浆中淀粉的二次多项数学模型。结果:最佳酶解条件为:加酶量480U/g,作用时间90min,反应温度77℃,pH值6.0,底物浓度2.6g/10ml。结论:在最佳酶解条件下,甘薯中还原糖最大估计值为13.97345%,实测值为(13.968±0.05)%。     

α-淀粉酶水解魔芋飞粉最佳条件优化的研究

本研究采用单因素和正交试验的方法对α-淀粉酶水解魔芋飞粉的酶用量、pH值、温度、[Ca2 ]和底物浓度等条件进行优化,结果表明当α-淀粉酶用量为4u/g淀粉、pH为6.0、温度为60℃、[Ca2 ]为0.01mol/L和底物浓度为8%时,水解度达20%,为最佳反应条件,研究为进一步利用α-淀粉酶水解魔芋飞粉生产燃料乙醇奠定了基础.     

淀粉类酶在烟叶中降解条件的研究

采用酶解的方法,在一定条件下向烟叶中施加一定量的α-淀粉酶的糖化酶,使烟叶中的淀粉降解为水溶性糖。实验得出α-淀酶粉／糖化酶的最佳用量分别为8（u/g)/80(u/g),可降解烟叶中的淀粉80％,烟叶中水溶性糖增加21．4％左右。最佳作用条件为：烟叶水分25％,酶的作用时间6h,作用温度30度,且在真空破膜条件下,效果更明显。     

海洋耐高温酸性α-淀粉酶水解玉米淀粉的研究

为开发适用于工业生产的新型酶制剂,以实验室自主构建的基因工程菌所产的新型海洋耐高温酸性α-淀粉酶为液化酶,以玉米淀粉液化后的DE值为指标,研究影响玉米淀粉的液化的因素,确定该酶水解玉米淀粉的最佳工艺条件。新型海洋耐高温酸性α-淀粉酶最佳的工艺条件为温度85℃、时间90 min、粉浆浓度250 g/L、酶用量32 U/g淀粉。     

超声波协同复合酶法提取姬松茸多糖

研究了超声波协同复合酶法提取姬松茸多糖的最佳工艺条件。采用均匀设计法分别考察不同时间、pH值、温度、酶浓度、固液比对纤维素酶、果胶酶以及木瓜蛋白酶酶解反应的影响,并研究三种酶联合使用时的加酶方式以及超声波协同提取时的最佳条件。结果表明,超声波协同复合酶法可显著提高姬松茸多糖的提取率,其最佳提取条件为：超声波作用20min,分步加酶法（先加果胶酶：pH值3．8、温度50℃、时间90min、加酶量7000U／g、固液比1：45;然后加纤维素酶：pH值3．6、温度75℃、时间120min、加酶量150U／g、固液比1：45;最后加木瓜蛋白酶：pH值3．6、温度75℃、时间120min、加酶量20000U／g、固液比1：45）,多糖提取率达到14．51％。     

直接加热膨化蔗渣酶法水解的研究

采用加热时间为２０ｍｉｎ,压力为２．０ＭＰａ,温度为１２０℃的直接加热膨化甘蔗渣为水解底物、日本ｙｓｋｕｌｔ生物化学试剂公司生产的ｏｎｏｚｕｋＲＳ型纤维纯洁酶粉进行蔗渣的酶法水解实验,考察了蔗渣中纤维素的酶解还原糖得率与反应时间、酶浓度、ｐＨ值、缓冲液种类、离子强度以及固液比的关系,结果表明：当固液比为５％（ｗ／ｖ）,酶浓度＞１．２０ｍｇ／ｍｌ时,还原糖得率随酶浓度的增加变化不显著;本实验条件下,缓冲液种类和离子强度对还原糖得率几乎没有影响;水解最适宜ｐＨ值为４．２～４．９;最佳反应温度为５０℃。     

异淀粉酶在α-环糊精制备中的应用及条件优化

环糊精具有外侧亲水内部空腔疏水的桶形结构,可与众多的各类大小、形状合适的疏水性客体分子形成包合物,改变其理化性质。其中,α-环糊精(α-CD)具有较小的空腔、溶解性好及耐酸解,因此在很多领域具有特殊的应用。目前,单独采用环糊精葡萄糖基转移酶(α-CGTase)生产α-CD的底物利用率低,而已开发的双酶法不仅底物成本高,而且环糊精总转化率及α-CD比例也有待提高。因此,为了提高α-CD的得率,降低生产成本,本研究将α-CGTase与异淀粉酶复配,以木薯淀粉为底物,对酶转化条件进行了优化。结果表明,当底物浓度15%,液化时间10 min,温度40℃,反应p H 5.5,异淀粉酶加量144 U/g底物,α-CGTase加量15 U/g底物,正癸醇浓度5%(v/v),转化周期18 h,环糊精总转化率为90.5%,α-CD所占比例为96.3%,α-CD的转化率为国内外报道的最高水平。     

微生物酶拆分方法生产D-泛酸的手性中间体D-泛解酸内酯

筛选到一株产D－泛解酸内酯水解酶的串珠镰孢霉菌（Fusarium moniliforme SW-902)。产酶条件研究表明,用甘油作碳源,蛋白胨作氮源,初始pH8.0,温度26℃,摇瓶培养3d,产酶量最高。在60L和1000L发酵罐中通风发酵45－47h,产酶量为6－8g干菌体／L,D－泛解酸内酯水解酶酶活力达到0．87－0．92IU／g干菌体。该酶的最适反应温度为55℃,最适反应pH为7．0－7．5。在酶不对称水解泛解酸内酯过程中,对溶液加酶量5％－10％,底物浓度10％－20％,控制水解率20％－30％,水解效果最好。     

60Co-γ射线辐照协同氢氧化钠预处理对油菜秸杆酶解产糖的影响

研究了辐照协同氢氧化钠预处理油菜秸秆对酶解产还原糖的影响。利用响应面法对氢氧化钠反应条件进行了优化,得出最优条件为氢氧化钠浓度为2．38％,反应温度为100℃,反应时间为0．5h。这一条件预期还原糖产量为524．93mg／g,通过实验验证,实际还原糖含量（528．51mg／g）能够很好地与预期相吻合。扫描电镜观察表明,辐照协同氢氧化钠预处理后秸秆表面积明显增大,出现很多蜂窝状孔洞结构,能够有效增大酶解可及表面积,从而提高酶解效率。     

嗜热真菌 Thermomyces lanuginosus热稳定a—淀粉酶的纯化及特性

嗜热真菌Thermomyces lanuginosus在液体培养基中于50℃静止培养14d,培养液经硫酸铵分级沉淀、DEAE-Toyopearl离子交换层析、Butyl-Toyopearl疏水层析、SephacrylS-300分子筛层析和FPLC MonoQ离子交换层析,得到了凝胶电泳均一的淀粉酶。纯酶与淀粉反应不同时间后,用碘色反应法和DNS法测定淀粉和还原糖量,结果显示淀粉量在开始时迅速下降,但还原糖的量却增加很慢;产物经TLC层析分析为麦芽糖和少量葡萄糖。由此说明它为α-淀粉酶。用SDS-PAGE和Sephacryl S-300分子筛层析测定分子量为56000,不具亚基。酶反应最适温度和pH分别为65℃和4.5～5.0。在pH4.6条件下,酶在50℃是稳定的;60℃保温1h,仍保留94％的原酶活性;酶在70℃的半衰期为10min。钙离子对酶有激活作用。酶对糖原和糊精有一定的水解能力。     

Acid hydrolysis of sweet potato for ethanol production

Studies were conducted to establish optimal conditions for the acid hydrolysis of sweet potato for maximal ethanol yield. The starch contents of two sweet potato cultivars (Georgia Red and TG-4), based on fresh weight, were 21.1 +/- 0.6% and 27.5 +/- 1.6%, respectively. The results of acid hydrolysis experiments showed the following: (1) both hydrolysis rate and hydroxymethylfurfural (HMF) concentration were a function of HCL concentration, temperature, and time; (2) the reducing sugars were rapidly formed with elevated concentrations of HCl and temperature, but also destroyed quickly; and (3) HMF concentration increased significantly with the concentration of HCl, temperature, and hydrolysis time.Maximum reducing sugar value of 84.2 DE and 0.056% HMF (based on wet weight) was achieved after heating 8% SPS for 15 min in 1N HCl at 110 degrees C. Degraded 8% SPS (1N HCl, 97 degrees C for 20 min or 110 degrees C for 10 min) was utilized as substrate for ethanol fermentation and 3.8% ethanol (v/v) was produced from 1400 mL fermented wort. This is equal to 41.6 g ethanol (200 proof) from 400 g of fresh sweet potato tuber (Georgia Red) or an ethanol yield potential of 431 gal of 200-proof ethanol/acre (from 500 bushel tubers/acre).     

超临界下有机酸对稻秆水解糖化的影响

采用间歇式反应器在超临界条件下,以有机酸（甲酸、乙酸和丙酸）为催化剂对稻秆进行水解糖化研究,重点考察反应温度、反应时间、固液比对还原糖产率的影响。实验表明：有机酸的加入有利于稻秆的水解糖化,稻秆水解速率和还原糖产量都有所提高,这种趋势在加入甲酸时最为明显;随着反应时间的延长,还原糖产量会逐渐减少;适当提高固液比有助于增加还原糖产量。稻秆超临界水解糖化的最佳条件：甲酸体积分数3％、固液比4：60（g／mL）、反应温度410℃、反应时间5min,在此条件下,还原糖产量最高,达6．65g／L。     

Direct fermentation of potato starch in wastewater to lactic acid by<Emphasis Type="Italic">Rhizopus oryzae</Emphasis>

The fungal species ofRhizopus oryzae 2062 has the capacity to carry out a single stage fermentation process for lactic acid production from potato starch wastewater. Starch hydrolysis, reducing sugar accumulation, biomass formation, and lactic acid production were affected with variations in pH, temperature, and starch source and concentration. A growth condition with starch concentration approximately 20 g/L at pH 6.0 and 30°C was favourable for starch fermentation, resulting in a lactic acid yield of 78.3%–85.5% associated with 1.5–2.0 g/L fungal biomass produced in 36 h of fermentation.     

化学-酶法制备L-高苯丙氨酸

以苯丙酸乙酯为原料,通过正交设计优化2-氧4-苯基丁酸盐的制备条件：苯丙酸乙酯与草酸二乙酯摩尔比为1：3,缩合反应时间为2．5h,H2SO4质量分数为20％,水解反应时间为15h,优化条件下2-氧-4-苯基丁酸盐的产率为68．24％。随后,利用E．coli A5所产的天冬氨酸转氨酶为生物催化剂制备L-高笨丙氨酸。酶转化反应的最适条件为：游离细胞体系pH、温度、底物质量浓度和细胞质量浓度分别为8．5、37℃、20g/L和30g／L;而固定化细胞体系则分别为7．0—9．0、40℃、10g／L和30g/L。采用廉价的L-谷氨酸（L—Glu）作为氨基供体,添加表面活性剂有利于提高L-HPA产率。通过研究固定化细胞转化反应进程,结果发现8h内90％的底物可转化为L—HPA。     

稀酸水解玉米芯制备丁二酸

利用正交设计得到稀H2SO4水解玉米芯制备混合糖液的优化工艺:玉米芯料液比1∶5(质量体积比),物料粒径250~380μm、H2SO4用量3%(体积分数)、水解温度126℃、反应时间2.5 h。此工艺条件下的总糖收率达90%,总糖质量浓度为60 g/L,发酵抑制物糠醛含量为0.87 g/L,5-羟甲基糠醛含量为0.68 g/L。在此基础上利用活性炭吸附和Ca(OH)2中和对玉米芯混合糖液进行脱毒及脱盐处理,SO42-脱除率达96%,色素脱除率为96%,糠醛、5-羟甲基糠醛及多酚类物质脱除率均高于50%。处理后的玉米芯多组分糖液作为产琥珀酸放线杆菌(Actinobacillus succino-genes)NJ113的发酵C源,当培养基中初始总糖质量浓度为50 g/L时,丁二酸收率为61.68%,丁二酸质量浓度为30.8 g/L;初始总糖质量浓度为70 g/L时,丁二酸收率仍可达50%以上,丁二酸质量浓度为35.2 g/L。发酵实验表明,将经过脱毒脱盐处理的玉米芯多组分糖液替代葡萄糖作为C源发酵制备丁二酸具有可行性。     

酶法破碎裂殖壶菌提取胞内油脂

采用酶法破碎裂殖壶菌提取胞内油脂,进行单因素实验和正交实验优化酶解反应条件,酶解反应的影响因素主次顺序依次为酶用量、温度、时间、pH,最佳酶解工艺参数:55 ℃、pH 9.5、搅拌反应2.5 h、酶用量为菌体生物量的2%.在该条件下,胞内油脂的提取量高达(81.53±0.33) g/L,过氧化值仅为0.15,酸价为0.24.     

The effect of process conditions on the alpha-amylolytic hydrolysis of amylopectin potato starch: An experimental design approach

The hydrolysis of amylopectin potato starch with Bacillus licheniformis alpha-amylase (Maxamyl) was studied under industrially relevant conditions (i.e. high dry-weight concentrations). The following ranges of process conditions were chosen and investigated by means of an experimental design: pH [5.6-7.6]; calcium addition [0-120 microg/g]; temperature [63-97 degrees C]; dry-weight concentration [3-37% [w/w]]; enzyme dosage [27.6-372.4 microL/kg] and stirring [0-200 rpm]. The rate of hydrolysis was followed as a function of the theoretical dextrose equivalent. The highest rate (at a dextrose equivalent of 10) was observed at high temperature (90 degrees C) and low pH (6). At a higher pH (7.2), the maximum temperature of hydrolysis shifted to a lower value. Also, high levels of calcium resulted in a decrease of the maximum temperature of hydrolysis. The pH, temperature, and the amount of enzyme added showed interactive effects on the observed rate of hydrolysis. No product or substrate inhibition was observed. Stirring did not effect the rate of hydrolysis. The oligosaccharide composition after hydrolysis (at a certain dextrose equivalent) did depend on the reaction temperature. The level of maltopentaose [15-24% [w/w]], a major product of starch hydrolysis by B. licheniformis alpha-amylase, was influenced mostly by temperature.     

Studies on the production and application of cellulase from Trichoderma reesei QM-9414

High yielding mutant strain, Trichoderma reesei QM-9414, was employed for the cellulase enzyme production. Enzyme production conditions (pH, inoculum age and concentration, and organic supplements) were optimized. The ability of partially purified enzyme to hydrolyze various regionally abundant lignocellulosic raw materials was studied. Enzymatic hydrolysis conditions (temperature, pH, enzyme and substrate concentrations) were optimized. Temperature 50v°C, pH 4.5, enzyme concentration 40 FPU/g substrate and substrate concentration 2.5% were found to be optimum for the maximum yields of sugars. #-glucosidase supplementation was found to increase both the sugar yield and hydrolysis rate, and shorten the reaction time significantly.     

重组人抗凝血酶发酵条件的优化

目的:通过实验室发酵条件优化工作,实现在巴斯德毕赤酵母中高效表达重组人抗凝血酶。方法:在摇瓶培养条件下,应用正交实验方法考查人抗凝血酶重组毕赤酵母菌pPIC9K-AT-02的培养温度、培养基pH值、接种比例、甲醇补加间隔时间及甲醇补加浓度等5种因素对重组人抗凝血酶活性的影响,确定最优发酵条件。结果与结论:筛选出的最终发酵条件为培养温度30℃、培养基pH6.0、接种比例20%、甲醇补加间隔时间24 h、甲醇补加浓度2%,重组人抗凝血酶在巴斯德毕赤酵母中表达活性为4098 U/L,比原始活性提高了150%。