营养盐浓度对航天搭载盐藻生长及胞外多糖含量的影响

比较了培养液中不同营养盐浓度对“神舟5号”搭载盐藻(Dunaliella salina)和非搭载盐藻的生长及胞外多糖积累的影响,发现经“神舟5号”搭载后盐藻最适营养盐浓度发生了变化。非搭载盐藻培养液中最佳单因子组合为:CaC l2200 mg/L、MgC l2500 mg/L、KNO31 000 mg/L、KH2PO455 mg/L。搭载盐藻培养液中最佳单因子组合为:CaC l2250 mg/L、MgC l2500 mg/L、KNO31 000 mg/L、KH2PO415 mg/L。搭载和非搭载盐藻胞外多糖累积的最佳单因子组合相同:CaC l2、MgC l2、KNO3、KH2PO4分别为250、2 000、500、15 mg/L,但搭载盐藻胞外多糖的分泌明显高于非搭载盐藻。     

恶臭假单胞菌S1产胞内海藻糖合成酶发酵培养基的优化

采用摇瓶发酵法研究了不同碳源、氮源对恶臭假单胞菌S1干重和胞内海藻糖合成酶酶活力的影响。通过正交试验得出其最佳培养基配方为(g.L-1):葡萄糖25,玉米浆15,麦芽糖20,豆粕水解液10 mL.L-1,Na3C6H5O7.2 H2O 0.5,Na2HPO4.12 H2O 0.5。优化后菌体密度、单位细胞产酶活力分别提高了1.44倍和72.16%。     

未成熟杏胚离体培养

ImmatureEmbryoCultureofApricotinvitroWANGYuZhu,SHIHons（PomologyandForestInstitute,AgricultureandForestryScienceAcademyofBeijing,Beijing100093）1植物名称杏（Prunusarmeniaca）极早熟品种“骆驼黄”。2材料类别盛花后41、46和57d的未成熟胚。3培养条件培养基为Tukey、SH、Norstog［KNO3160mg／L（单位下同）,Ca（NO3a）2·4H2O290,NaH2PO4·H2O800,Na2SO4200,MgSO4·7H2O730,KCl140,FeC6H5O7（1％）10,H3BO30.5,CuSO4·5H2O0．25,MnSO4·4H2O3,ZnSO4·7H2O0．5,Na2MoO4·2H2O0．…     

产油微藻的选育及其培养条件优化

为了利用微藻处理废水生产生物质燃料，实现治理环境污染和缓解化石能源短缺的耦合，需要筛选能够适应石家庄本地气候，生产状况良好且油脂产率较高的微藻藻株。从石家庄市自然河流中采样，经过BG11培养基分离纯化后筛选出10株微藻，利用SPASS 19.0软件对培养中的相关数据进行方差分析及LSD多重比较发现，自养条件下藻种DK-3生物量、总脂含量较其他藻株高,分别为：1.86 g·L-1、(10.23 ± 2.63) mg·L-1·d-1，经18S rDNA 鉴定为栅藻（Scenedesmus meyen），构建其系统发育树。利用Box-Behnken Design (BBD)设计耦合响应曲面法（RSM）探索藻种DK-3最佳异养培养条件，最终藻种DK-3最佳培养条件为葡萄糖20 g·L-1、K2HPO4·3H2O 90 mg·L-1、MgSO4·7H2O 200 mg·L-1（其他成分参考BG11培养基），经验证在此培养条件下，经240 h培养后生物量为5.47 g·L-1，油脂产量为1.28 g·L-1，比对照组生物量3.37 g·L-1提高了62.31%，因此，藻种DK-3具有较高的研究潜能。     

也门铁的组织培养技术研究

以4品种也门铁的茎段为外植体进行组织培养技术研究。结果表明,控制普通也门铁茎段褐化效果最理想的培养基为MS + 0.25 g·L-1 VC + 0.50 g·L-1 Na2S2O3;诱导也门铁不定芽萌动的最佳培养基为MS + 3.0 mg·L-1 6-BA + 0.2 mg·L-1 NAA + 0.1 mg·L-1 KT;诱导也门铁不定芽增殖的最佳培养基,因品种不同而异,普通也门铁和金心也门铁为MS + 2.0 mg·L-1 6-BA + 1.0 mg·L-1 NAA + 0.1 mg·L-1 GA3,扭纹铁和金心扭纹铁为MS + 1.0 mg·L-1 6-BA + 0.5 mg·L-1 NAA + 0.1 mg·L-1 GA3;也门铁壮苗的最佳培养基为MS + 0.05 mg·L-1 6-BA + 0.05 mg·L-1 NAA + l g·L-1AC;也门铁生根最优培养基为1/2MS + 0.5 mg·L-1 IBA。     

根瘤菌4012a菌株产细胞分裂素发酵条件的研究

用酶标免疫检测法研究了根瘤菌4012a菌株细胞分裂素发酵的适宜培养基和培养条件。结果表明,其最佳培养基为（g／L）：葡萄糖10.0,（NH4）2SO41.0,K2HPO4·3H2O0．6,MgSO4·7H2O0.1,CaCl2·2H2O0.4,FeCI3·6H2O0．04,Na2MoO4·2H2O0．1mg／L,泛酸钙100μg／L,腺漂吟200mg／L。该菌株在150r／min的旋转摇床上27℃振荡培养96h,发酵液中细胞分裂素产量可达908μg／L,生物活性（萝卜子叶扩大法）为1mg／L激动素当量。     

化学药剂对水稻种子萌发和幼苗生长的影响

以早丰 11号水稻种子为材料 ,用KNO3、KH2 PO4 、Na2 HPO4 等不同药液浸种 .结果显示 ,早丰 11号种子在适当浓度的KNO3、KH2 PO4 、Na2 HPO4 浸种后 ,发芽势、发芽率比对照有所提高 ,幼苗生长加快 ,表现在根长、发根数、苗高、鲜重比对照生长好 ,并且对水稻秧苗表现有抵抗低温的作用 .     

Medium optimization of α-glucosidase inhibitors production by response surface analysis

[目的]采用响应面法对戈壁三素链霉菌PW409发酵合成α-糖苷酶抑制剂的培养基进行优化.[方法]采用Plackett-Burman法筛选影响α-糖苷酶抑制剂产生的关键因素,用最陡爬坡试验逼近关键因素的最大响应区域,采用Box-Behnken设计以及响应面分析法,得到各因素的最佳浓度,通过液相色谱-串联质谱法(LC-MS/MS)对发酵液中α-糖苷酶抑制剂进行定量分析.[结果]发酵培养基中可溶性淀粉、KNO3和K2HPO4的浓度对α-糖苷酶抑制剂的产量影响较大.优化后的培养基组成为:可溶性淀粉9.01 g/L,KNO311.0 g/L,K2HPO4 0.32 g/L,MgSO4·7H2O 0.50 g/L,FeSO4·7H2O 0.01 g/L,pH 7.5.[结论]在此优化条件下,链霉菌PW409发酵液对麦芽糖苷酶的半数抑制浓度IC50为22 mg/L,抑制活性较优化前提高了近10倍.发酵液中的1-脱氧野尻霉素含量可达7.84 mg/L,较优化前提高了668倍,米格列醇的含量可达0.94 mg/L,较优化前提高了10倍.     

利用响应面法优化α-糖苷酶抑制剂发酵培养基

【目的】采用响应面法对戈壁三素链霉菌PW409发酵合成α-糖苷酶抑制剂的培养基进行优化。【方法】采用Plackett-Burman法筛选影响α-糖苷酶抑制剂产生的关键因素,用最陡爬坡试验逼近关键因素的最大响应区域,采用Box-Behnken设计以及响应面分析法,得到各因素的最佳浓度,通过液相色谱-串联质谱法(LC-MS/MS)对发酵液中α-糖苷酶抑制剂进行定量分析。【结果】发酵培养基中可溶性淀粉、KNO3和K2HPO4的浓度对α-糖苷酶抑制剂的产量影响较大。优化后的培养基组成为:可溶性淀粉9.01 g/L,KNO3 11.0 g/L,K2HPO4 0.32 g/L,MgSO4.7H2O 0.50 g/L,FeSO4.7H2O 0.01 g/L,pH 7.5。【结论】在此优化条件下,链霉菌PW409发酵液对麦芽糖苷酶的半数抑制浓度IC50为22 mg/L,抑制活性较优化前提高了近10倍。发酵液中的1-脱氧野尻霉素含量可达7.84 mg/L,较优化前提高了668倍,米格列醇的含量可达0.94 mg/L,较优化前提高了10倍。     

不同营养盐及浓度对黄丝藻Tribonema sp. FACHB-1786生长及脂质积累的影响

丝状微藻黄丝藻Tribonema sp.具有抗浮游动物捕食、易收获、油脂含量高等优点,且其脂肪酸组分中含有丰富的棕榈油酸 (Palmitoleic acid,PA) 和二十碳五烯酸 (Eicosapentaenoic acid,EPA),被认为是生产生物柴油和高附加值产品的重要原料。为了提高黄丝藻脂质生产效率,文中研究了不同浓度的氮 (NaNO3：255–3 060 mg/L)、磷 (K2HPO4：4–240 mg/L)、铁 ((NH4)3FeC12H10O14：0.6–12 mg/L)、镁 (MgSO4：7.5–450 mg/L) 元素对黄丝藻FACHB-1786生长、油脂积累和脂肪酸组分的影响。结果表明,培养基中磷、铁、镁三种元素的浓度对黄丝藻生长具有显著影响,其中增加MgSO4浓度可显著提高黄丝藻的生物量,当MgSO4浓度增加至450 mg/L时,获得最大生物量为8.09 g/L,显著高于目前报道的有关黄丝藻自养条件下获得的生物量;氮元素浓度对黄丝藻的生长没有显著影响 (P>0.05),但高浓度氮元素有利于黄丝藻脂质的积累;黄丝藻FACHB-1786在765 mg/L NaNO3、80 mg/L K2HPO4、6 mg/L (NH4)3FeC12H10O14、75 mg/L MgSO4的营养盐条件下可获得最大总脂单位体积产率、棕榈油酸和EPA产率,分别为319.6 mg/(L·d)、135.7 mg/(L·d)和24.2 mg/(L·d)。研究结果为后期黄丝藻的生产应用提供一定的理论依据和参考。     

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