还原型谷胱甘肽高产菌株的初筛及其提取工艺优化

目的:筛选还原型谷胱甘肽(GSH)高产菌株并优化其提取工艺.方法:从中科院沈阳应用生态研究所菌种保藏室的酵母菌库中筛选GSH高产的酵母菌,改进培养基组分,提高胞内GSH含量,并优化热水抽提和乙醇提取两种方法,提高提取液中GSH含量.结果:筛选获得一株酿酒酵母Y,其胞内GSH含量9.60 mg/g,培养基改良后,胞内GSH含量又提高了34.8%.通过单因素和正交试验确定热水抽提法最优提取条件为:料液比1∶3,pH 2.0,在90℃水浴中,抽提10min,GSH的产量可达14.27mg/g干菌体.结论:添加氨基酸和葡萄糖都有利于酵母菌体的生长和GSH合成.热水抽提法较乙醇提取法相比,提取效果好、无污染、操作简单,为后续的分离纯化工作奠定基础.     

热水提取酿酒酵母中S-腺苷-L-甲硫氨酸的研究

研究了采用热水法直接提取酿酒酵母胞内产物S-腺苷-L-甲硫氨酸（SAM）北京,并且通过实验对影响SAM抽提的5个条件：抽提温度、抽提时间、热水用量、搅拌转速、硫酸用量等进行了优化。得出的最佳实验条件为：温度70℃、每30g湿菌体加入热水100mL、硫酸浓度0．25mol／L、搅拌转速160r／min,此时SAM的抽提率可达91．5％。与其他方法相比,该方法耗时少、仪器简单、抽提液中S-腺苷-L-甲硫氨酸质量浓度高、经济且无污染。     

产谷胱甘肽昆虫共生酵母菌的筛选、鉴定和培养条件优化

从水黾肠道中分离并筛选到1株产还原型谷胱甘肽(GSH)的酵母菌株SM3,经初步鉴定为Candida carpophila菌。通过正交实验优化菌株产GSH的最佳培养基成分:3%蔗糖为碳源,0.2%(NH4)2SO4为无机氮源,0.8%酵母浸粉为有机氮源,K2SO40.3%,KH2PO40.6%,MgSO40.15%。单因素实验表明其较佳培养条件为:接种量15%,培养时间36 h,摇床转速200 r/min,温度32℃,pH 6.0,装液量为20/250 mL。优化后GSH产量可达159.35 mg/L,较优化前提高了105.27%。     

灰灰菜抗菌物质提取及抗菌效果研究

研究了从灰灰菜中以95％的乙醇提取有效抗菌物质的工艺条件,并通过正交实验,确定其提取最佳工艺条件为：抽提比为1：10,回流温度为90℃,回流时间2．5h;其提取液的最大吸收峰为366nm。通过抑菌实验和对照实验,发现其提取液对金黄色葡萄球菌和大肠杆菌有明显的抑菌效果,对青霉也有一定抗菌效果。     

若羌大枣多糖提取及分离工艺研究

目的：确定大枣多糖提取分离工艺的参数。方法：采用热水浸提法取多糖,乙醇沉淀法分离多糖。对液固比、浸提时间、浸提温度进行了单因素和L9（3^3）正交实验,并对提取过程中影响提取率的因素进行了统计分析。对多糖浸提液浓缩倍数、乙醇沉淀体积、醇沉时间对大枣多糖得率的影响进行了研究。结果：最佳提取工艺条件为：提取时间6h,料水比1：24,提取温度90℃。最佳分离工艺：浓缩倍数为8倍,4倍体积乙醇,醇沉12h,大枣多糖的得率最大。结论：实验结果为新疆次级大枣的深加工提供了可参数据。     

蝉蜕中甲壳素的提取工艺优化及其抗氧化活性和止血效果评价

该研究以蝉蜕为原料,通过单因素结合正交实验,对超声辅助酸碱提取蝉蜕中甲壳素的工艺条件进行优化;以ABTS、DPPH及O₂^-自由基清除率为指标,评价提取物的抗氧化活性;通过提取物对兔血凝固时间的影响以及对不同出血模型出血时间、出血量的影响来评价提取物的止血效果。结果表明,蝉蜕中甲壳素的最佳提取工艺为：脱钙：质量分数：8%盐酸,温度：室温,料液比：1∶25,超声功率：160 W,超声时间：150 min;脱蛋白：质量分数：10%氢氧化钠,温度：60℃,料液比：1∶25,超声功率：无显著差异,超声时间：90 min;脱色：质量分数：5%高锰酸钾、8%亚硫酸氢钠,温度：90℃,时间：高锰酸钾反应60 min、亚硫酸氢钠反应90 min;蝉蜕甲壳素对ABTS、DPPH及O₂^-自由基均有一定的清除能力;相同剂量的蝉蜕甲壳素粉末与云南白药粉末相比,蝉蜕甲壳素体外促凝血能力更优,且蝉蜕甲壳素显著地缩短了鼠尾出血时间、出血量及肝创口的出血时间。该研究可为昆虫类中药的高值化利用与综合开发提供借鉴。     

用改进的方法从酵母制取还原型谷胱甘肽(GSH)结晶

磨碎732离子交换树脂,筛选60—80目组分用于吸附酵母抽提液中的GSH,2N硫酸洗脱,新鲜CU_2O沉淀CuGS。最后,含GSH的溶液通N_2减压浓缩得到GSH结晶。熔点195℃,含量99%,总收率40%。     

应用液—液双水相抽提技术分离纯化甘油激酶、a-甘油磷酸脱氢酶及心肌黄酶

用液-液双水相抽提技术分别从嗜热脂肪芽胞杆菌(Bacillus stearothermophilus)菌体、兔肌及猪心肌匀浆液中分离甘油激酶、a-甘油磷酸脱氢酶及心肌黄酶,研究了pH,匀浆液的量、氯化钠浓度及丙酮等因素对分配系数、上下相体积之比,酶活性回收率及分离效果等参数的影响,并确定了抽提上述三种酶的最佳相组成系统。用本文的工艺抽提甘油激酶、a-甘油磷酸脱氢酶及心肌黄酶有下列优点： 1．酶活回收率较高,分别为90％、95％及70％2：分离效果较好,通常提纯三、四倍以上3．各酶均存留在下相,即磷酸钾盐富相中,故可省去聚乙二醇(PEG)的分离工序而直接与后继精制工艺衔接,简化了工艺,在实验室及工业生产中均有实用价值。     

香圆种子萌发特征及催芽技术

以香圆（Citrus wilsonii Tanaka）种子为实验材料,通过测定种皮透水性、种皮机械障碍、发芽温度等对种子萌发的影响从而探讨种子萌发特征;通过切割种子、热水浸种、赤霉素浸种、低温层积等处理方式探索种子的催芽方法。结果显示：香圆种皮不存在透水性障碍,但其机械障碍对种子萌发具有抑制作用,且内种皮对萌发影响较大;种子在15℃、25℃、35℃恒温及15℃/30℃变温条件下均可萌发,其最适萌发温度为25℃;采用低温层积、热水浸种、切除1/3种子等方法均可一定程度上促进种子萌发。生产中宜采用始温60℃热水浸种24h的方法对香圆种子进行催芽。     

文冠果种子油提取工艺

以石油醚（60~90℃）为溶剂,通过单因素和正交实验优化了提取文冠果种子油工艺,得到的最佳工艺参数为：种仁粒径为2 mm,提取温度为90℃,提取时间为10 h,料液比为1：5（W/V）。在最佳提取条件下,平均提取率可达62.49%。利用高效液相色谱技术分析了油脂的脂肪酸组成,结果表明其主要成分与一般生物柴油主要成分基本相同,文冠果种子油将是生产生物柴油原料的新来源。     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV