满江红鱼腥藻的异养生理

设计了一个经机械处理而获得蓝藻无菌培养物的方法,利用这一方法获得满江红鱼腥藻(Anabaena azollae)的无菌培养物。满江红鱼腥藻的无菌培养物能以果糖、葡萄糖或者蔗糖为底物,在黑暗中进行化能异养生长。将适应了光能自养生长的培养物转移至黑暗中异养生长时,以NaNO3为氮源时的生长速率比以空气中的氮气为氮源时高;然而适应了化能异养生长的培养物以空气中的氮气为氮源时生长更佳。搅拌促进生长。满江红鱼腥藻在黑暗中生长半年后,叶绿素a的含量降至光照下生长时的1/3-1/4。满江红鱼腥藻在5500勒克斯光照下生长时,添加外源果糖或葡萄糖仍能促进生长,提高固氮活性。     

满江红鱼腥藻的相对耐热性

利用加温处理引起藻丝叶绿素a可变荧光强度的变化,以测定满江红鱼腥藻(Anabaena azollae imbricata)的相对耐热性。藻丝在25℃下可变荧光和固定荧光的比值为0.35±0.05;在37℃下(5分钟),相应的比值为0.27;在45℃下比值降至0.11。在50℃下,叶绿素a可变荧光几乎完全消失。较高温度可能引起光合电子传递链成分的构象和功能的变化,减少了光能的利用。结果表明满江红鱼腥藻可以忍受37℃的温度。     

满江红鱼腥藻遗传多样性的RAPD分析

共生在水生蕨类植物满江红(又称“红萍”:Azolla)叶腔中的固氮兰细菌曾被认为是一个种满江红鱼腥藻(Anabaena azollae Strasb.).但由于现存的满江红在分类学上有2个亚属,7个种1,对不同满江红叶腔中鱼腥藻的鉴别,多年来引起人们的重视.80年代,鱼腥藻的单克隆抗体和RFLP的研究,发现了它与宿主分类上一定程度的对应关系2,3.90年代以后,Van Coppenolle和Eskew分别以RAPD-PCR和DAF-PCR对从满江红共生体中提取的DNA进行了分析4,5,但后者发现了共生体中藻的DNA对整个PCR产物的干扰作用会影响满江红属本身系统分类.       

满江红与满江红鱼腥藻共生体的某些生长发育特性研究

满江红(红萍、绿萍)是蕨类中唯一与蓝藻共生而具固氮能力的共生体。我国农民早就注意到满江红可以肥田的特性,把它养殖在稻田里作绿肥。解放后在政府的大力推动和组织下满江红的养殖得以大规模推广,目前我国是世界上养萍面积最大的国家,积累了丰富的经验,也已有专著出版。     

鱼腥藻HB1017株化能异养生长的研究

以葡萄糖和蔗糖为碳源,检测了六株（种）鱼腥藻的化能异养生产能力。其中鱼腥藻ＨＢ１０１７株化能异养生长较快,鱼腥藻ＨＢ０株化能异养生长缓慢,其余四种鱼腥藻不能进行化能异养生长。鱼腥藻ＨＢ１０１７株能利用果糖、葡萄糖、蔗糖为底物进行化能异养生长,但生长速率依次递减,差别显著。８磅湿热灭菌的果糖和蔗糖,与过滤灭菌的相比,只能维持低得多的化能异养生长速率。然而,８磅湿热灭菌的葡萄糖能维持比过滤法灭菌的高得     

不同波长光下生长的柱孢鱼腥藻和满江红鱼腥藻的荧光光谱特性

在日光灯下生长的满江红鱼腥藻(Anabaena azollae),其叶绿素a所吸收光的激发能在两个系统间的分配相近于柱孢鱼腥藻(A.cylindrica)。两个光系统发射荧光强度与藻蓝素发射荧光强度的比值分别较柱孢鱼腥藻高,但两个光系统荧光发射强度的比值较低。满江红鱼腥藻藻蓝素吸收光的激发能有效地传递给两个光系统,并以较大的比例分配至光系统Ⅰ。在520 nm光下的满江红鱼腥藻,其叶绿素a所吸收光的激发能,与柱孢鱼腥藻相比,以较大的比例分配给光系统Ⅱ;而在600 nm光下的藻丝,其叶绿素a所吸收光的激发能在两个光系统间的分配与柱孢鱼腥藻相近似。600 nm光提高了满江红鱼腥藻别藻蓝素所吸收光的激发能对光系统Ⅱ荧光发射的贡献。生长在600 nm光下的藻丝较生长在520 nm光下的藻丝有更高的叶绿素a所吸收光的激发能传递效率。藻丝生长在不同波长光下有着不同的叶绿素a和藻蓝素所吸收光的激发能传递和激发能在两个光系统间的分配。     

满江红鱼腥藻引入刺松藻体内的初步观察

满江红为蕨与鱼腥藻的共生体已早为人们所熟知。生活于满江红共生腔中的满江红鱼腥藻能否在适当的条件下与其它植物共生呢?当它与其它细胞处在一起的时候会有什么样的关系呢? 最近 Gusev 将一种蓝藻(Chlorogloea fritischii)加入人参的悬浮培养物中,发现二者可以结合成一个共生体。生于温带、热带海边的刺海松属于管藻目,藻体呈圆柱状分枝,柔软。内部由管状的     

蓝光对满江红鱼腥藻吸收光谱和荧光光谱特性的影响

生长在蓝光下的满江红鱼腥藻的β-胡萝卜素吸收与叶绿素a和藻蓝素吸收的比值较生长在日光灯光下的藻丝低,即在相同的β-胡萝卜素吸收基础上,生长在蓝光的藻丝有更大比例的叶绿素a和藻蓝素的吸收,在相同的叶绿素a含量的基础上,生长在蓝光下的藻丝,其光系统Ⅱ和光系统Ⅰ发射荧光强度与藻蓝素发射荧光强度的比值皆较生长在日光灯光下的藻丝高。藻蓝素所吸收光的激发能有效地传递给两个光系统。光系统Ⅱ可变荧光强度和固定荧光强度的比值亦较生长在日光灯光下的藻丝高。藻丝细胞在蓝光下具有高的色素所吸收光激发能传递效率和激发能利用效率,使满江红鱼腥藻更有较地利用共生体内环境的较短波长的光。     

满江红鱼腥藻与其宿主的遗传多样性和协同性的RAPD分析

从16个代表不同种属或地域来源的满江红样本中分离出共生藻并通过处理获得无藻的满江红宿主,对二者同步进行了RAPD扩增,分别得到了大量DNA多态片段。通过建立满江红鱼腥藻及其宿主的UPGMA聚类关系图,看出二者在遗传分支上存在着一定程度的协同对应关系。但在种内的不同品系间,这种协同性有所减少,发现有的品系的共生藻发生了明显的变异。 Abstract:Symbiotic Anabeana azollae and its host plant Anabeana-free Azolla were isolated from 16 Azolla accessions representing different Azolla species or geographic origins.DNA polymorphic fragments were obtained by simultaneous RAPD amplification of both symbiont and host.The UPGMA clusters of Anabeana azollae and its host Azolla were established separately based on Dice coefficient caculation and a coordinated relationship was shown between Anabeana azollae and its Azolla host along both individual genetic divergence,but this genetic homology was reduced among different strains within Azolla species while the obvious mutants of Anabeana azollae were detected in some Azolla tested strains collected from different geographic area in the same host species.     

我国鱼腥藻的新记录种——粘质鱼腥藻

蓝藻是淡水水体的重要组成类群,而鱼腥藻又是水华蓝藻的一个重要种属.但由于该属种类较多,国内文献报导的不到世界分布的四分之一.该文利用染色和显微镜镜检方法对采自广东省高州水库蓝藻水华的样品进行观察,经鉴定,确认一个我国鱼腥藻属的新记录种--粘质鱼腥藻Anabaena mucosa, J. Komarkova-Legnerova & P. Eloranta ,1992 .对该属及该属一个新记录种的主要形态学特征进行了描述,提供了相应的形态照片,并对相似种进行了形态学比较研究.     

柱胞鱼腥藻原生质球自发融合的研究

早在1976年,细菌就实现了原生质体融合杂交[1]。同样是原核生物,蓝藻原生质球融合及细胞杂交至今没有任何报道。究其原因,首先是由于蓝藻原生质球再生技术长期不过关、近年来,蓝藻原生质球再生虽有若干报道[2～4],但再生技术还不够成熟;另一方面,很早就通过电镜检查发现     

HYDROGENASE ACTIVITY OF CELL-FREE PREPARATION OBTAINED FROM THE BLUE-GREEN ALGA, ANABAENA CYLINDRICA

A cell-free preparation of hydrogenase was obtained from acetone-driedcells of Anabaena cylindrica. This preparation was capable ofcatalyzing the reduction of various redox dyes by molecularhydrogen and evolution of hydrogen from reduced methyl viologen.PMS, methylene blue, DPIP and toluidine blue were effective,in this order, as hydrogen acceptors. Ferricyanide, p-quinone,phenosafranine and neutral red were not reduced by the presentpreparation. PPNR obtained from this alga was effective on neitherreduction of NAD and NADP by hydrogen nor stimulation of hydrogenuptake with methylene blue and PMS. Coupled with hydrogenasereaction, there occurred reduction of nitrate to ammonia whenmethylene blue was added to the reaction mixture. ¹Present address: Department of Zoology, University of Texas,Austin, Texas, U.S.A.     

THE FINE STRUCTURE OF THE NUCLEAR MATERIAL OF A BLUE-GREEN ALGA,ANABAENA CYLINDRICA LEMM

The chromatinic material of the blue-green alga Anabaena cylindrica has complex configurations in the central regions of the cells. The distribution of the chromatin within the cells varies in different filaments, probably in response to variations in the disposition of other cellular components. In electron micrographs of thin sections of organisms fixed by the method of Kellenberger, Ryter, and Séchaud (1958) the centroplasm contains fibrillar and possibly granular components which can be identified as the nuclear material by comparison with stained preparations viewed in the light microscope. The fibrils in the nuclear regions have diameters in the range of 5 to 7 mµ and are embedded in a matrix of lower density. The nuclear regions are not greatly different from the cytoplasm in their electron density. Reducing the calcium content of the fixative results in coagulation of the fibrils to form coarser structures. The significance of the observations is discussed in relation to observations on the fine structure of other classes of algae and of bacteria.     

LIGHT-INDUCED REDUCTION OF NITRATE, NITRITE AND HYDROXYLAMINE IN A BLUE-GREEN ALGA, ANABAENA CYLINDRICA

1. Reduction of nitrate, nitrite and hydroxylamine by intact cellsof Anabaena cylindrica was investigated with special referenceto the stimulating effect of light on these processes.
2. Itwas found that in light and under anaerobic condition thesecompounds are reduced to ammonia, with the production of extraoxygen. The stoichiometry of the reactions under these conditionscan be represented as follows: HNO₂+H₂O=NH₂+2O₂ HNO₂+H₂O=NH₂+1O₂ NH₂OH+H₂O=NH₂+O₂+H₂O
3. Reduction of nitrite and hydroxylaminewas markedly suppressedby CMU in the light but not in the dark.KCN inhibited reductionto the same extent both in the lightand in the dark. Reductionin the light was much less sensitiveto the uncoupling agent,DNP, than was that in the dark.
4. Atlow light intensities, CO_2– was suppressed by 20–30per cent by the simultaneous provision of nitrite, but the nitritereduction was not affected at all by CO₂. At high light intensities,reduction of nitrate and nitrite was considerably acceleratedby CO₂
5. On the basis of these findings, a possible mechanismfor thelight stimulation of the reactions in question was brieflydiscussed.

(Received August 22, 1962; )     

ISOLATION,GROWTH, AND RESPIRATION OF A THERMOPHILIC BLUE-GREEN ALGA

Holton , Raymond W. (U. Texas, Austin.) Isolation, growth, and respiration of a thermophilic blue-green alga. Amer. Jour. Bot. 49(1): 1–6. Illus. 1962.—The isolation of a bacteria-free culture of Hapalosiphon laminosus (= Mastigocladus laminosus) from an algal mass obtained from Liard Hot Springs, British Columbia, is described. Seven different bacterial media at 2 incubation temperatures were used to test for bacteria in suspensions of partially broken up algae. The algal growth rate was obtained by calculating the slope of the straight line obtained in a plot of the cube root of the dry wt against time. In cultures aerated with air the growth was optimal between 35 and 50 C, with an upper limit at 55 and a lower limit at 25. Aeration with 1% CO₂ in air significantly increased growth rates and the optimum was at 45–50 C. Unaerated flasks grew more slowly than aerated ones. The endogenous Qo₂ (in μl/hr–mg dry wt) at 45 was 8.0 for growing cells and 2.8 for starved cells kept in darkness 18 hr. The Qo₂ was maximal between pH 7.0 and 8.5. The concentration of phosphate buffer affected the Qo₂ and rates in 0.02 M were slightly greater than those in distilled water and much greater than those in 0.4 M. The Qo₂ of growing cells was slightly stimulated by 2,4-dinitrophenol (DNP), whereas glucose or glucose plus DNP did not affect it. In contrast, the endogenous Qo₂ of starved cells was nearly doubled in glucose and tripled in DNP plus glucose.     

固氮蓝藻高光放氢突变种的筛选和放氢特点

作者以前报道过几种快速生长的固氮蓝藻在某种条件下能好气光放氢,其速度可以达到光合放氧速度的10—15%,但这种活性只有在不积累氢气的流动气相下或在短时间内发生。本文报道用亚硝基胍诱变所得到的Anabaena spp。Strain CA的高光放氢突变种——N9A和18A——的筛选和氢代谢特点。在达生长饱和光照以后,野生型的光放氢活性与光照强度的增加成正相关,而其吸氢活性则与之成负相关,显示高光照强度可能抑制吸氢酶的活性。无论在什么光强下,均测不到两个突变种的吸氢活性,暗示在突变种中,吸氢酶或有关系统受损伤。把细胞固相化在琼脂上,在密闭系统中,高光强下培养50个小时,两个突变种光释放和积累的氢分别为野生型的2倍(N9A)和6倍(18A),后者等于氢占气相(1%CO_2的空气)的1.8%。两个突变种在生长速度、叶绿素含量、乙炔还原活性以及光合放氧方面与野生型无明显不同。当以含50—100nM的镍离子的培养基培养时,野生型的好气净产氢活性完全丢失,其吸氢活性却增加约10倍。培养基中镍离子的存在,对两个突变种的高光放氢活性则毫无影响,而且在此情况下,仍测不出其吸氢活性。实验结果表明,这两个突变种系吸氢酶缺陷型突变种。