蚕蛹蛋白质的酶—酸两步水解

将木瓜蛋白酶催化水解和酸水解联合起来应用于水解蚕蛹蛋白质制备氨基酸。与单纯酶解(水解时间48h)或酸水解(水解时间24h)相比,水解时间分别缩短了2/3和1/3,后处理简化,能耗降低。研究了蚕蛹蛋白质水解的影响因素,在适宜条件下,得到有香味的混合氨基酸,收率为98.5％(对蛋白质),其中含有17种游离氨基酸(色氨酸未测),含量为47.9％。     

以动物脏器——猪腰渣为原料提取氨基酸

<正> 利用本厂生产的废渣——猪腰渣为原料,提取精氨酸、组氨酸,余下的酸性氨基酸和中性氧基酸作为本厂产品的营养添加剂,是实验的主题。围绕这个题目,我们有两个实验方案:第一法,腰渣经酸水解浓缩减酸脱色后。以串接的大小二根732阳离子柱吸附全部氨基酸,根据氨基酸在柱上的色谱分布按区段分头洗脱,以缩短生产周期。用此法进行三批试验,得精氨酸收率为3.9%,2.1%,4.0%,组氨酸收率为0.4%和1%,从试验得率,讨论了水解完全后继续     

利用蚕蛹生产复合氨基酸营养物研究——Ⅲ 蚕蛹酸水解330树脂脱酸制备混合氨基酸研究

本文对蚕蛹酸水解用330树脂脱酸制混合氨基酸及酸水解时间进行了研究,得到的结果是:常压下适宜的酸解时间为22小时。330树脂脱酸法最高收得混合氨基酸达83.26%,具有工艺简单,生产周期短,成本低,收率高等优点。     

猪血粉制备复合氨基酸工艺研究

本文采用正交试验法优选硫酸水解猪血粉制备复合氨基酸的最佳条件,经中试及工业规模生产证明:复合氨基酸收率平均为53.3％,氨基酸含量为72.7％。     

猪毛中胱氨酸的分离和复合氨基酸的制备

本文研究了以猪毛为原料,经过水解、赶酸、中和、结晶、精制提取出胱氨酸纯品;并从分离胱氨酸后的母液中,经过脱色、离子交换、浓缩、结晶、精制,制备出复合氨基酸.在本工艺条件下,胱氨酸产品的收率为4.8%,纯度在99%以上;复合氨基酸产品的收率为41%,纯度在83%以上.本文为扩大试验打下了基础.     

水蚯蚓制备混合氨基酸的研究

本文报导以水蚯蚓为原料,用酸水解法与离子交换树脂相结合制备混合氨基酸,收得率为蛋白质的41.11％,含量77.66％,计含16种氨基酸,必需氨基酸占7种。产品洁白无异味,易使用户接受,并具成本低,得率高,社会效益与经济效益兼备等优点。     

角蛋白质酸水解法介绍

<正> 角蛋白质经酸水解可以获得多种氨基酸,水解时,酸比、温度和时间三个因素关系到水解产品的收率。近年来许多国家对毛发水解因素研究颇多,在水解工艺上提出了一些改进意见:1.Warenke 提出用钴、镍、铜的离子作催化剂可以加速 DL—丝氨酸甲酯的水解速度2.Davis Clyde Faward Jr 提出用金属络合物作催化剂可以加速多肽化合物的水     

工业废羊毛酸解工艺条件选择

毛发蛋白盐酸水解提取胱氨酸时 ,温度、毛酸比、时间等因素影响到毛发蛋白的水解率和产品胱氨酸的总收率。通过正交试验法 ,进行了废羊毛酸解工艺参数的试验研究 ,确定了最佳酸解工艺参数为 :温度 1 0 5℃ ,毛酸比(W/V) 1∶1 .7,连续水解时间 7.0h。     

鸡羽毛制备复合氨基酸铁铵的研究

本文介绍了以鸡羽毛为原料,采用盐酸水解,经与铁络合、调ＰＨ值制备复合氨基酸铁铵的方法。收率为４４．２％,总铁含量９．６％,游离铁含量０．４２％。废物充分利用,工艺简单易行。     

茶叶中氨基酸的提取方法研究

比较了沸水、0.1 mol·L-1盐酸、甲醇、无水乙醇、85％乙醇、60％乙醇等不同溶剂提取茶叶中氨基酸的效果,结果以60％乙醇超声波法提取60 min最好;比较了用6 mol·L-1盐酸采用电磁水解法和超声波法提取茶叶中氨基酸的效果,电磁水解法优于超声波法,但电磁水解法对含硫氨基酸破坏较大.     

Enzymatic production of cyclodextrins from milled corn starch in an ultrafiltration membrane bioreactor

Cyclodextrin glycosyltransferase (CGTase) was found to be severely inhibited by cyclodextrins. In order to increase the conversion yield by reducing product inhibition and reuse the CGTase in the production of cyclodextrins from milled corn starch, an ultrafiltration membrane bioreactor system was employed. In a batch operation with ultrafiltration, the conversion yield was increased 57% compared with that without ultrafiltration. Operating conditions for the continuous production of cyclodextrins in the membrane bioreactor were optimized by taking into consideration the filtration rate and the conversion yield as follows: initial starch concentration, 7% (w/v); starch feeding rate, 240 mg/h; CGTase loading, 350 units/initial gram starch. When cyclodextrins were continuously produced in the membrane bioreactor under optimized conditions, 340 units of CGTase was require to produce 1 g of cyclodextrins for 48 h, while in the case of conventional batch operation, 1 g of cyclodextrins was produced for 24 h by 1410 units of CGTase. (c) 1993 John Wiley & Sons, Inc.     

胆红素提取工艺中的皂化水解条件

为提高胆红素生产效益,采取正交实验法,优化皂化水解pH、温度和时间。结果表明:在pH12.0、105℃、20 min时,胆红素粗制品收率平均为0.866 7 g/L,但纯度仅为24.01%,折合纯品收率为0.208 1 g/L。胆红素的纯度在pH11.0、100℃、10~30 min时,平均纯度为67.91%,但粗制品收率仅为0.402 2 g/L,折合纯品收率为0.273 1g/L。胆红素的折合纯品收率,在pH10~12、100℃、20 min时,平均可达0.366 8 g/L,粗制品收率为0.568 9 g/L、纯度64.12%,此时胆红素的生产效益比传统方法提高了43.9%。     

Effects of spacing interval of wide bed planting on canopy characteristics and yield in winter wheat

2010-2012连续两年在大田试验条件下以多穗型品种‘百农矮抗58’为供试材料, 研究了宽幅播种(播幅8 cm)种植方式下不同带间距7 cm (KF7)、12 cm (KF12)和17 cm (KF17)对冬小麦(Triticum aestivum)冠层特征及产量的影响。结果表明: 与常规条播比较, 宽幅播种群体叶面积指数、平均叶倾角、光截获量、相对湿度、成穗数、生物量和产量较高, 而冠层开度和温度较低; 2010-2011年和2011-2012年宽幅播种成穗数和产量显著高于常规条播, 成穗数分别增加4.8%-16.4%和8.9%-21.0%, 产量分别提高2.96%-15.94%和4.09%-14.23%。宽幅播种下随带间距增大, 叶面积指数、平均叶倾角、光截获量、湿度及成穗数降低, 而冠层开度和温度升高; 穗粒数、千粒重、产量、生物量和收获指数以KF12最高, KF7最低。综合分析, 宽幅播种下12 cm带间距处理的小麦冠层结构合理, 微环境适宜, 产量最高, 可作为该种植方式的适宜带间距。     

高GC含量DNA模板的PCR扩增

目的：探索高GC含量DNA的PCR扩增条件,为扩增达托霉素生物合成基因簇及拼接奠定基础。方法：在PCR扩增体系中,使用高保真的聚合酶及添加不同浓度的DMSO、7-deaza-dGTP等增强剂,并选择合适的PCR循环程序,优化富含GC的DNA的PCR扩增条件。结果：向反应体系中额外添加1%~4%的DMSO可以显著提高富含GC的DNA的PCR扩增产物量,但会降低其特异性;7-deaza-dGTP可以提高扩增产物的特异性及保真度,但产量会有所下降。应用touch down PCR并在体系中添加7-deaza-dGTP能够提高扩增产物的特异性和产率,增加扩增的保真度。结论：应用优化的PCR扩增条件将所有达托霉素生物合成基因簇分段扩增出来,并可扩增出长达6 kb的片段,且序列完全正确,可以进行后续拼接。     

不同耕作方法对水稻生长和土壤生态的影响

1998－1999年在华南双季稻田研究了不同耕作方法水稻生长和土壤生态的影响,结果表明,在抛秧条件下,免耗水稻分蘖数,有效穗数和实粒数减少,水稻产量比传统耕降低13．4％,经济效益减少10．9％,免耕土壤容重和硬度增大,癖孔隙度,非毛管孔隙度和有效P,K降低,放线菌和真菌数量减少,而土壤细菌数量增加,酶活性增强,轻耕和传统耕的土壤物理化学性质,微生物数量和酶活性相似,但轻耕水稻有效穗数和千粒重较高,水稻产量比传统耕增加2．1％,轻耕降低了耕作成本,经济效益比传统耕作提高11．0％。     

Industrial production of monoclonal antibodies and therapeutic proteins by dialysis fermentation

A novel and powerful fermentation method is reported for the large-scale growth of mammalian cells and their secreted products. The system described illustrates many of the advantages of conventional batch fermentation processes but in addition has been shown to yield cell densities in excess of 1×10⁷ cells/ml with concomitant increase in product concentration.Abbreviations MAb Monoclonal Antibody - STR Stirred Tank Reactor - FBS Foetal Bovine Serum     

几种氨基酸在庆大霉素生产中作用的研究

庆大霉素是氨基糖苷类广谱抗生素,其不仅用于临床治病,而且广泛应用于畜牧业。由于其发酵周期长,产素率低,生产成本高,因此改进生产方法势在必行。本文报道了在绛红色小单孢菌产生庆大霉素的培养过程中,添加一定量的甘氨酸、蛋氨酸、赖氨酸、酪氨酸能够有效地提高微生物细胞的代谢能力,缩短发酵培养周期,提高产素率。本方法是在小试（摇瓶）成功基础上,用5L玻璃发酵罐运转一个多月,取一个月的平均罐批数据表明：新方法较原工艺发酵周期缩短30% ~45%,罐批产量增加14% 左右,产素率提高30 % ~95%（因菌种生产能力不同而异）,产品质量符合中国药典2000版（CP2000）、英国药典2000版（BP2000）、美国药典26版（USP26）,生产成本大幅度降低,具有很强的市场竞争力。     

Preparation of high purity biphenyl cyclooctene lignans from Schisandra extract by ion exchange resin catalytic transformation combined with macroporous resin separation

In this study, ester-bond biphenyl cyclooctene lignans were efficiently hydrolytically degraded into free biphenyl cyclooctene lignans by ion exchange resin transformation and simultaneous removal of impurities by macroporous resin. The OH-type strongly basic anion exchange resin 201×7 was the best one, and the dynamic hydrolysis efficiency was 146.7±5.0%. HPD5000 macroporous resin, which offered higher adsorption and desorption capacities and faster adsorption than other resins. The purity of free biphenyl cyclooctene lignans in the product increased from 5.14±0.24% to 79.67±0.0.67%. After dynamic catalytic transformation by 201×7 resin combined with purification of HPD5000 resin, the yield and the purity of free biphenyl cyclooctene lignans in the product were 132.1±4.7% and 80.91±3.53%, respectively.     

Modeling of an integrated fermentation/membrane extraction process for the production of 2-phenylethanol and 2-phenylethylacetate

An unstructured model for an integrated fermentation/membrane extraction process for the production of the aroma compounds 2-phenylethanol and 2-phenylethylacetate by Kluyveromyces marxianus CBS 600 was developed. The extent to which this model, based only on data from the conventional fermentation and separation processes, provided an estimation of the integrated process was evaluated. The effect of product inhibition on specific growth rate and on biomass yield by both aroma compounds was approximated by multivariate regression. Simulations of the respective submodels for fermentation and the separation process matched well with experimental results. With respect to the in situ product removal (ISPR) process, the effect of reduced product inhibition due to product removal on specific growth rate and biomass yield was predicted adequately by the model simulations. Overall product yields were increased considerably in this process (4.0 g/L 2-PE+2-PEA vs. 1.4 g/L in conventional fermentation) and were even higher than predicted by the model. To describe the effect of product concentration on product formation itself, the model was extended using results from the conventional and the ISPR process, thus agreement between model and experimental data improved notably. Therefore, this model can be a useful tool for the development and optimization of an efficient integrated bioprocess.     

An efficient method for production of uridine 5'-diphospho-N-acetylglucosamine

Uridine 5'-diphospho-N-acetylglucosamine (UDP-GlcNAc) has been synthesized by a yeast-based method from 5'-UMP and glucosamine, in which yeast cells catalyze the conversion of 5'-UMP to 5'-UTP and provide enzymes involved in UDP-GlcNAc synthesis using 5'-UTP and glucosamine as substrates. However, this conventional method is not suitable for practical production of UDP-GlcNAc because of the low yield of the product. We found that the yqgR gene product of Bacillus subtilis, which has been identified as a glucokinase, can catalyze the phosphorylation of N-acetylglucosamine (GlcNAc) to give GlcNAc-6-phosphate, an intermediate of UDP-GlcNAc biosynthesis. The addition of the yqgR gene product to the yeast-based reaction system enabled us to synthesize UDP-GlcNAc using GlcNAc in place of glucosamine. The addition of two enzymes, GlcNAc-phosphate mutase and UDP-GlcNAc pyrophosphorylase, increased the yield of UDP-GlcNAc. Using this novel method, UDP-GlcNAc was produced at an amount of 78 mM from 100 mM 5'-UMP and 100 mM GlcNAc.