一种放线菌发酵产天然蓝色素的研究*

对一种放线菌产生天然蓝色素的发酵条件作了详细探讨。单因素发酵试验表明 ,碳源以2 %的蔗糖最佳 ;氮源以 0.1%的KNO₃为最好。正交试验表明 ,蓝色素发酵最佳配方为 :4%蔗糖 +0 1 %KNO₃+0.075 %盐 +1 0μg/mLFeSO₄。最佳培养温度为 3 0℃ ;最佳初始pH为 7 4。并测定了罐发酵过程中的溶解氧、pH变化及碳、氮的利用情况。用HPLC法对该色素的各成分进行了分离 ,结果显示 ,该蓝色素至少含有以放线紫红素     

嗜酸乳杆菌P302菌株产类细菌素最佳条件的研究

目的对产类细菌素嗜酸乳杆菌P302的发酵条件进行研究。方法采用琼脂扩散法测定发酵上清液对大肠埃希菌O139的抑菌活性。结果通过正交试验确定P302产类细菌素的最佳培养基组分为牛肉膏4％、胰蛋白胨0．2％、酵母粉0．8％、碳酸钙0．4％和蔗糖1％,0．4％复合维生素,0．3％Tween-80有利于类细菌素的产生。发酵工艺条件为最适初始pH7．0,最适温度37℃,最佳接种量0．3％,种龄14h,厌氧培养22h。结论通过优化发酵条件和发酵工艺,类细菌素的产量提高了35％。     

一种崂山百合的离体快速繁殖技术

以崂山百合的鳞茎为外植体,通过植物组织培养技术成功获得了再生植株,建立了该植物的快速无性繁殖体系。整个组织培养过程分为芽的诱导、根的诱导和移栽三个阶段。适合芽诱导的最佳外植体是：鳞茎基部,最适培养基是：1／2MS＋0．5mg／LNAA＋0．8mg,LKT＋3％蔗糖。用于生根的最佳培养基是：1／2MS＋0．4mg/LIBA＋3％蔗糖。最适培养温度为25℃．不同基质对组培苗移栽的成活率有一定影响,其中在珍珠岩上的移栽成活率为98％。     

一种快速高效诱导大豆再生的方法

ARapidandEffectiveMethodtoInduceSoybeanRegenerationZHAOGui-ying,CHENHang(BeijingVegetableResearchCentre,Beijing100081)1植物名称大豆（Glycinemax）品种京黄1号、里外青、黑皮青、丰南黄豆。2材料类别无菌种子萌发6d的子叶柄。3培养条件（1）种子前发及诱导芽分化培养基：1／2MS＋6－BAP1．0mg·L－1＋3％蔗糖十0．7％琼脂，pH5．8~6．0。（2）生根培养基：1／2MS＋NAA0．1mg·L－1＋2％蔗糖十0．7％琼脂，pH5．8~6．0。培养温度25~28℃，光照16·d－1，光照度3500lx。4生长与分化情况4．1萌发种子用75％酒精浸泡30…     

毛蕊铁线莲的组织培养与植株再生

1植物名称毛蕊铁线莲（Clematis lasiandra Maxim．）,别名小木通、丝瓜花。2材料类别带芽茎段、节间和叶片。3培养条件诱导培养基：（1）MS＋6-BA0．5mg．L-1（单位下同）＋NAA0．05＋3％蔗糖;（2）MS＋6-BA0．5＋NAA0．1＋2,4-D0．1＋3％蔗糖;（3）MS＋6-BA2．O＋NAA0．1＋3％蔗糖。增殖分化培养基：（4）MS＋6-BA1．0＋NAA0．1＋3％蔗糖;（5）MS＋6．BA2．0＋NAA0．1＋2,4-D0．01＋3％蔗糖;（6）MS＋6．BA2．0＋NAA0．05＋3％蔗糖。生根培养基：（7）1／4MS＋NAA0．5＋0．1％活性炭＋15％蔗糖。所有培养基均附加0．6％琼脂粉,pH5．8-6．0,培养温度为（25±2）℃,光照强度为3040gm01．m-2．S-1,光照时间为14h．d-1。     

大豆根瘤菌HH103菌株培养基的筛选与优化

以快生型大豆根瘤菌HH103菌株为供试菌株,采用单因素碳氮源利用试验和正交设计试验,确定最佳培养基及其配方。结果表明：该菌株在YMA中生长良好,最佳碳源为蔗糖,最佳氮源为酵母膏,最佳培养基成分配方（g/L）：蔗糖11,酵母膏0.9,K2HPO4 0.5,MnSO4 0.005,CaCl2 0.1,KH2PO4 0.5,MgSO4 0.2,KNO30.77,（NH4）2HPO4 0.33,FeCl3 0.005,pH 7.2。     

栀子蓝色素的发酵及分离纯化工艺的研究

以宇佐美曲霉AS3．758为发酵菌株、栀子黄废液为原料,以液态发酵方式生产栀子蓝色素,通过正交试验法优选栀子蓝色素的最佳工艺条件。结果为：培养温度为29％、发酵液pH为6．5、发酵培养时间为36h,发酵结束后经水解、过滤,滤液中加入谷氨酸钠,反应后得栀子蓝色素液,转化率达98．43％。色素液经D301离子交换树脂吸附,再用1.0mol／L盐酸洗脱,洗脱液经低温干燥得到的栀子蓝色素,色价E1cm ^1%（590nm）达55．6。     

BP神经网络优化微生物浸矿工艺

以低品位黄铜矿溶液为原料,浸矿制备Cu2＋能有效提高低品位黄铜矿的利用价值。基于浸矿过程中存在多因素影响的现象,通过正交试验与神经网络分析方法,对浸矿条件（接种量、矿石品位、Fe2＋添加量及浸矿溶液pH）实行优化。结果表明：在正交试验组中最佳试验结果为浸矿产128．753mg／LCu^2＋;BP神经网络优化后的最佳实验组合为微生物接种量12％、矿石品位0．3％、添加Fe^2＋24g/L及浸矿溶液pH1．7,该条件下验证试验产Cu^2＋ 141．352mg／L,通过正交试验及神经网络优化提高了微生物浸出低品位黄铜矿酸性溶液Cu^2＋的产量。     

黄山药愈伤组织诱导与分化

采用黄山药野生植株作为外植体,试验了不同激素处理对黄山药愈伤组织的诱导、分化影响,结果表明：不同的外植体的诱导率差别较大,叶片的诱导率最高,最高达到85．7％,茎段的诱导率较低,平均诱导率仅10％左右。以叶片作为外植体诱导愈伤组织的最佳培养基配方为MS 2,4-D2．0mg／L 6-BA2．5mg／L;愈伤组织分化生芽的最佳配方为MS BA1．0mg／L NAA0．5mg／L 蔗糖2％ pH6．4;愈伤组织分化生根的最佳配方诱MS BA1．0mg／L NAA0．1mg／L 蔗糖3％ pH6．80。     

蛹虫草中虫草素、虫草多糖综合提取工艺研究

以蛹虫草为材料．采用超声波水提法、超声波醇提法、水热回流法和醇热回流法4种提取方法选择虫草素和虫草多糖的最优提取办法．并用正交试验方法考察水热回流法中提取温度、提取次数、提取时间、料液比4个因素对虫草素、虫草多精综合提取效率的影响．以确定从蛹虫草中综合提取虫草素、虫草多糖最佳工艺。结果表明．水热回流法是提取虫草多糖和虫草素的最优提取方法．其最佳工艺条件为：用10倍量的水于80℃热回流提取3次．每次90min。     

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