微藻减排CO2制备生物柴油的研究进展

碳减排与可再生能源的开发利用是研究可持续发展的热点,而微藻在此方面具有巨大优势.利用微藻减排CO2合成生物柴油生产原料油脂,对于解决能源短缺和全球变暖具有重大战略意义.将碳减排与微藻生物柴油的制备方法相结合,对微藻转化CO2合成生物油脂的机制,微藻油脂积累的影响因素以及国内外在工业上的研究概况等方面进行综合归纳和评述,并对微藻生物油脂的发展前景进行了展望.     

Fe~(3+)对小球藻的生长及油脂含量的影响

传统化石能源储量日益减少,生物柴油因其环保可再生性成为优质的石化柴油替代品。利用小球藻生产生物柴油速度快、油脂含量高,受到了广泛关注。为进一步提高小球藻生产生物柴油效率,分别探究了Fe3+的浓度及添加时间对自养和异养小球藻生长及产油的影响,获得最优Fe3+培养条件为:自养小球藻延滞期添加10-3 g/L Fe3+,生物量及油脂含量达2.80 g/L及30.90%;异养小球藻指数期添加10-5 g/L Fe3+,生物量及油脂含量达3.30 g/L及29.05%。经脂肪酸分析,以上条件获得的微藻油脂均可作为生物柴油生产原料。     

我国微藻生物柴油的研究背景与发展战略

生物柴油是可再生能源开发利用的重要发展方向。藻类制备生物柴油具有产油量高、生长速度快、环境适应能力强、不与农作物争夺农田和淡水资源等优势。从微藻制备生物柴油着手,简要介绍了生物柴油的生产原料与发展历程、微藻油脂的组成与生物合成途径、微藻制备柴油的工艺与瓶颈及解决策略,最后对微藻制备生物柴油技术提出了近中远期发展目标及展望。     

基于模糊综合评价的产生物柴油微藻藻种筛选

产生物柴油微藻大规模培养对微藻藻种的性能要求较高。从丰富的藻种资源中筛选到高品质的藻种一直是个亟待解决的问题。通过研究3株产油微藻,从系统工程的角度综合整个微藻生物柴油的技术工艺,建立了以生长速率、含油率、油脂组成等18种指标的二级评价体系,采用二级模糊综合评价的模糊数学方法对产生物柴油微藻的性能进行综和分析、筛选。最终确定供评价的三株微藻二级模糊综合评价集：小球藻LICME001［0.360 0.315 0.192 0.069 0.064］,微绿球藻LICME002［0.277 0.331 0.236 0.104 0.052］和葡萄藻LICME003［0.325 0.371 0.232 0.071 0.060］。根据最大隶属度法则分析得：小球藻LICM001株产生物柴油微藻品质为优等级别,适合产生物柴油的技术工艺要求;微绿球藻LICME002和葡萄藻LICME003为良等级别的产生物柴油藻种。     

微藻生物柴油的发展

微藻生物柴油是一种具有较大发展潜力的可再生能源,与动、植物为原料制备的生物柴油相比,它有不占用耕地、产油效率高等优点。目前,微藻生物柴油在国内外都有很大发展,产业化的进程也在逐步推进。介绍了高油脂含量微藻的种类、微藻合成油脂的机理研究、微藻的培养技术及微藻生物柴油的产业化现状,并对微藻生物柴油发展中的一些问题进行了分析。     

三角褐指藻产油突变株的筛选

能源短缺和原油价格上涨是全球关注的问题之一, 生物柴油作为一种优质的替代液体燃料越来越受到重视。以油料作物、废食用油和动物脂肪为原料生产生物柴油已远远不能满足需求。相比而言, 产油微藻具有光合效率高、生物量大、油含量高、生长速率快、不受季节的限制及不占用耕地等优势15, 被认为是制备生物柴油燃料的更有潜力的原料。由于目前微藻生物柴油生产成本过高, 尚未获得商业化生产。       

微藻藻种的筛选和育种及基因工程改造

正利用微藻油脂、烷烃或微藻淀粉生产生物柴油或生物酒精已成为国际生物能源研究领域的前沿和各个国家尤其是西方发达国家能源科技竞争的热点。然而,微藻生物燃料面临用于大规模工业化培养的微藻品种较少、生产成本高而难于商业化应用的问题。文章深入研究微藻生物技术的发展,对目前微藻藻种筛选、育种和基因工程技术改造进行分析,为进一步发掘筛选新的微藻生物资源、获得富含生物燃料原料成分及多种生物活性成分的优良藻种提供指导,加快微藻的生物产品和生物燃料商业化生产。     

微藻生物柴油技术的研究现状及展望

微藻生物柴油是一种优良的可再生新能源,对于解决人类面临的能源短缺和全球变暖两大危机具有潜在的重大战略意义。综述了微藻生物柴油的技术流程、油脂含量较高的微藻藻种、微藻生物柴油的最大技术瓶颈、提高微藻油脂总产量的方法、微藻的大规模培养、微藻的采收和微藻生物柴油的制取等方面的研究现状,并对微藻生物柴油未来的核心研究方向提出了初步见解。     

富油脂微藻育种技术研究进展

微藻因生长迅速、光合作用效率高、分布范围广和油脂积累能力强等优势,已被认为是生产生物柴油的理想原料。诱变育种可改善野生型微藻生长缓慢、油脂含量低和环境适应能力弱等缺陷,提高了以微藻生产生物柴油的可行性。概述了物理、化学和基因工程三类诱变育种方法的研究现状,介绍了低场核磁共振和荧光激活细胞分选两种富油脂微藻筛选技术以及一种测定诱变藻株致死率的方法,讨论了三种诱变方法的应用前景,供相关研究人员参考。     

生物柴油原料资源高油脂微藻的开发利用

生物柴油作为化石能源的替代燃料已在国际上得到广泛应用。至今生物柴油的原料主要来自油料植物, 但与农作物争地的情况以及较高的原料成本限制了生物柴油的进一步推广。微藻作为高光合生物有其特殊的原料成本优势, 微藻的脂类含量最高可达细胞干重的80%。利用生物技术改良微藻, 获得的高油脂基因工程微藻经规模养殖, 可大大降低生物柴油原料成本。介绍了国内外生物柴油的应用现状, 阐述了微藻作为生物柴油原料的优势, 对基因工程技术调控微藻脂类代谢途径的研究进展, 以及在构建工程微藻中面临的问题和应采取的对策进行了综述和展望。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Physiological characteristics of various species of strains of carboxydobacteria

Seven strains of aerobic carbon monoxide-oxidizing bacteria (carboxydebacteria) when growing on CO as sole source of carbon and energy had doubling times which ranged from 12–42 h. The activity profiles obtained after discontinuous sucrose density gradient centrifugation indicated that the CO-oxidizing enzymes are soluble and the hydrogenases are membrane-bound in all strains examined. The CO-oxidizing enzymes of Pseudomonas carboxydohydrogena, Pseudomonas carboxydoflava, Comamonas compransoris, and the so far unidentified strains OM2, OM3, and OM4 had a molecular weight of 230,000; that of Achromobacter carboxydus amounted to 170,000. The molecular weights of the CO-oxidizing and H₂-oxidizing enzymes turned out to be identical. The cell sonicates were shown to catalyze the oxidation of both CO and H₂ with methylene blue, thionine, phenazine methosulfate, toluylene blue, dichlorophenolindophenol, cytochrome c or ferricyanide as electron acceptors. Methyl viologen, benzyl viologen, FAD⁺, FMN⁺, and NAD(P)⁺ were not reduced. The spectrum of electron acceptors was identical for all strains tested. Neither free formate, hydrogen nor oxygen gas were involved in the CO-oxidation reaction. Methylene blue was reduced by CO at a 1:1 molar ratio. The results indicate that CO-oxidation by carboxydobacteria is catalyzed by identical or similar enzymes and that the reaction obeys the equation CO+H₂OCO₂+2H⁺+2e^- as previously shown for Pseudomonas carboxydovorans.Dedicated to Otto Kandler remembering almost three decades of enjoyable cooperation     

Modulation of allostery of pyruvate kinase by shifting of an ensemble of microstates

Since the introduction of the concepts of allostery about four decades ago, much advancement has been made in elucidating the structure-function correlation in allostery. However, there are still a number of issues that remain unresolved. In this review we used mammalian pyruvate kinase (PK) as a model system to understand the role of protein dynamics in modulating cooperativity. PK has a triosephosphate isomerase (TIM)(α/β)₈ barrel structural motif. PK is an ideal system to address basic questions regarding regulatory mechanisms about this common (α/β)₈ structural motif. The simplest model accounting for all of the solution thermodynamic and kinetic data on ligand-enzyme interactions involves two conformational states, inactive E^T and active E^R. These conformational states are represented by domain movements. Further studies provide the first evidence for a differential effect of ligand binding on the dynamics of the structural elements, not major secondary structural changes. These data are consistent with our model that allosteric regulation of PK is the consequence of perturbation of the distribution of an ensemble of states in which the inactive E^T and active E^R represent the two extreme end states. Sequence differences and ligands can modulate the distribution of states leading to alterations of functions. The future work includes: defining the network of functionally connected residues; elucidating the chemical principles governing the sequence differences which affect functions; and probing the nature of mutations on the stability of the secondary structural elements, which in turn modulate allostery.