蛹虫草液体培养条件的优化及生长动力学考察

为了优化蛹虫草菌的液体培养条件 ,对液体培养菌丝的生长情况进行了研究。采用摇瓶培养的方法 ,以发酵得率为指标确定培养条件。结果表明 :优化培养基成分确定为蛋白胨 1.5 % ,葡萄糖 2 % ,KH2 PO4 0 .15 % ,Mg SO40 .0 5 %、VB1 5 m g/ L .2 ,4 - D 2 mg/ L .该培养基下发酵得率达 1.4～ 2 .2 g/ 10 0 m L ;考察了蛹虫草菌液体培养的外部条件 ,确定为 :装料系数为 30 % ,培养基 p H为 5 .5 ,接种量为 0 .0 3g,摇床振荡频率为 12 0 r· m in- 1 ;利用优化培养基得到了生长代谢曲线。在相同条件下 ,优化培养基比原来培养基的发酵得率提高了 4 .5 % ,研究初步得到蛹虫草菌液体培养条件和生长动力学 ,为工业化生产提供了一定的依据     

X.ampelina TS206发酵制备冰核活性蛋白的研究

优化XanthomonasampelinaTS2 0 6的发酵制备条件可以提高冰核活性和生物量。通过摇瓶培养对该菌进行培养基成分和温度的筛选。实验结果表明 :( 1 )鱼蛋白胨和乳糖的浓度对冰核活性的提高产生显著影响程度 ,玉米浆影响程度较小 ;( 2 )生物量影响程度大小的顺序依次为鱼蛋白胨 >乳糖 >甘油 >玉米浆。优化的发酵培养基配方为 :酵母粉 1 0g L、大豆蛋白胨 1 0g L、硫酸镁 0 .5g L、蔗糖 2 0g L、鱼蛋白胨 1 5g L、乳糖 1g L、甘油 2 0g L、玉米浆 1 0g L ,pH 7.0。其较优的发酵温度为 1 8℃ ,发酵时间为4 8h ,能获得较高的冰核活性和生物量。     

MntH与含锰过氧化氢酶共表达基因工程菌的构建与发酵优化

构建Mn2+转运蛋白MntH与来源于Thermus thermophilus HB27的含锰过氧化氢酶的共表达基因工程菌,并进行了发酵培养基及培养环境条件的优化,确定培养基中最佳的碳氮源种类及其浓度分别为:甘油7.0 g/L,酵母粉3.75 g/L和蛋白胨11.25 g/L;当培养基中的Mn2+浓度为1 mmol/L时,最佳的IPTG诱导浓度为0.05 mmol/L。此外,最佳的培养基初始p H值及培养温度分别为:p H 8.0和37℃,在最优发酵条件下工程菌摇瓶发酵培养24 h,过氧化氢酶活最高可达476 U/m L是未优化前3倍。在5 L发酵罐的验证实验中,过氧化氢酶的酶活进一步提高至1 094 U/m L。     

一株凝结芽孢杆菌产生糖脂的工艺研究

对分离出的一株凝结芽孢杆菌生产糖脂的摇瓶发酵工艺进行了优化和 1 0L罐发酵实验。适宜发酵条件为 :培养基由 6 %豆油、 3 5g/LNaNO3、 0 75g/L酵母膏以及一定量的无机盐组成 ,发酵温度 3 0℃ ,初始pH8 5 ,搅拌转数 1 5 0～ 2 4 0r/min ,发酵周期 96h。糖脂产量达到 7 0 73g/L。     

金针菇FV908菌株液体培养工艺的研究

通过单因子试验统计分析 ,优化筛选了适于金针菇 (Flammulinavelutipes)FV90 8的适宜培养基和摇瓶培养条件 ,结果表明 ,其适宜的液体培养基组成为玉米粉 5 .0 % ,麸皮 2 .0 % ,KH2 PO4 0 .1% ,MgSO4 ·7H2 O 0 .0 5 % ,10 μgVB1/ 10 0mL ,5 0 μgVB2 / 10 0mL ;适宜的摇瓶培养条件为 :培养基的起始pH 6 .0～ 7.0 ,5 0 0mL摇瓶装量为15 0mL ,接种量为 10 % ,培养温度 2 5℃ ,摇床转速为 12 0r/min ,菌丝干收率 39g/L。     

暹罗芽胞杆菌FJAT-45551用于农业生物防治的优化培养

以具有防病促长且抑菌谱广的暹罗芽胞杆菌(Bacillus siamensis)FJAT-45551为出发菌株,分别以生物量和发酵液的青枯雷尔氏菌和尖孢镰刀菌抑菌活性为指标,通过单因子和正交试验对其培养基成分和发酵培养条件进行优化,从而提高其抑菌活性。结果表明,优化后的培养基配方为:麸皮20 g/L,蛋白胨25 g/L,MgSO_4·H_2O 0. 2 g/L,CaCl_20. 1 g/L,FeSO_4·7H_2O 0. 1 g/L,NaH_2PO_4·H_2O 0. 5 g/L,K_2HPO_40. 5 g/L;最适发酵培养条件为:接种量1%、摇床转速130 r/min、温度20℃、装液量50 mL(250 mL的摇瓶装液50 mL)、初始pH值为6. 0。在优化的发酵条件下,FJAT-45551发酵液对番茄青枯病菌(Ralstorinia solanacearum)FJAT-91的抑菌圈直径达30. 82 mm,较优化前的抑菌圈直径增加了9. 09 mm,抑菌活性提高了41. 83%。     

睾酮转化菌的筛选及发酵条件优化

采用亚硝基胍(NTG)对主产雄甾-4-烯-3,17-二酮(AD)的菌株YHT-1进行诱变,获得了一株睾酮(TS)产量较高的菌株YHT-103。通过对发酵条件及发酵培养基的优化,获得最佳培养条件为转化培养基:葡萄糖15 g/L,硝酸铵4g/L,MgSO40.5g/L,K2HPO40.5g/L,植物甾醇2g/L,tween80 6g/L,pH值6.5。种子培养时间30h,接种量10%,培养温度28℃。最佳转化条件下,获得最高TS转化率为46.20%。     

绣球花的组织培养(简报)

1、植物名称绣球花（Hydrageamaerophylla）,又名八仙花,虎耳草科多年生草本植物。2、组培材料带侧芽茎段。3、培养条件（1）侧芽诱导及增殖培养基：MS＋6－BA2．0～3．0mg／L＋NAA01～0．5mg／L,蔗糖30g／L,琼脂7g／L,pH6．0;（2）诱导生根培养基：1／2MS＋NAA0.5mg／L,蔗糖15g／L,琼脂用量和pH值同（1）。培养基用121℃高温高压灭菌30min,培养温度为24～27℃,光照强度为1500Lux,照光10h。4、生长与分化（1）侧芽诱导及增殖取生长健壮的绣球花茎段清洗后,经常规方法灭菌,用无菌水冲洗3～4次。切取2～2．5cm的带侧芽…     

大黄鱼细菌性病原哈维氏弧菌培养特性的研究

弧菌是危害水产养殖动物的最为严重的病原之一.从患病大黄鱼肝脏分离致病的细菌哈维氏弧菌GYC1108-1为材料,对哈维氏弧菌GYC1108-1株的最佳生长条件及培养基优化进行了测定.综合考察不同的培养温度、培养时间、培养基盐度、培养基的pH值对细菌生长的影响,并采用正交实验法,对培养基配方进行优化.结果表明:不同的培养温度、培养时间、培养基盐度、培养基pH值等均会影响细菌的产量.GYC1108-1适宜生长的盐度为1%-5%、pH为5～9.5、温度为15～35℃、在培养基中添加硫酸铜、硫酸氨会明显促进生长;最佳培养条件及培养基成份为:NaCl 2%,pH8.0,温度30℃,蛋白胨1.0%、牛肉膏0.75%、CuSO4 0.3mg/L、(NH4)2SO4 0.1g/L.     

应用改良滴冻法超低温保存两种柿属植物的研究

以君迁子（Diospyros lotus L．）和柿（D．kaki Thunb．）组培苗茎尖为试材,对影响超低温保存效果的主要因素,如低温锻炼方式、预培养条件、PVS：（30％甘油＋15％乙二醇＋15％二甲基亚砜＋0．4mol／L蔗糖）处理时间等进行了研究。建立了2种柿属植物的超低温保存程序：（1）切取1cm左右试管苗梢段继代到1／2MS（KNO3和NH4NO3减半）培养基中,交替低温[昼（25±1）℃、夜（4±1）℃]锻炼6周;在含0．5mol／L蔗糖的1／2MS培养基上预培养5d,20℃下装载液（2．0mol／L甘油＋0．4mol／L蔗糖）过渡10min,0℃下PVS2处理1．5h;（2）投入液氮保存;（3）40℃水浴化冻,洗涤5～6次后接种于含1．0mg／LTDZ、0．6g／L可溶性PVP、30g／L蔗糖和7．0g／L琼脂的培养基（作者在优化柿属植物离体培养体系试验中获得）上暗培养1周,转入25℃,1500lx培养室。按照上述程序培养,‘鄂柿1号’、‘湘西甜柿’和君迁子的成活率分别为79．6％、67．4％和60．9％。     

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     

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.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

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.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细