囊裸藻属与陀螺藻属囊壳微细结构及元素组成比较

对采自自然水体中囊裸藻属(Trachelomonas)的8种和陀螺藻属(Strombomonas)的两种藻类的囊壳微细结构和元素组成进行了比较分析,并探讨了这两个属的系统演化关系。结果表明：组成囊壳的矿质元素主要是铁和硅,在陀螺藻和表面粗糙的囊裸藻中,硅的含量较高,铁的含量相对较低;在大多数囊裸藻中,尤其是表面致密、光滑的种类中,铁的含量较高,硅的含量较低,矿质元素的组成与囊壳的颜色无直接关系。建议将陀螺藻属(Strombomonas)撤消,原陀螺藻属的种作为囊裸藻属(Trachelomonas)中的一个种组(Group),它们是裸藻科中最原始的具囊壳的类群。     

两种陀螺藻囊壳的微细结构和元素组成分析

利用从自然界水体中采集到的标本为材料,对2种陀螺藻的囊壳的微细结构和元素组成进行分析比较,结果表明：组成陀螺藻囊壳的主要矿质元素是硅(Si)、铁(Fe)和铝(A1),并含有少量的镁(Mg)、锌(Zn)、钙(Ca)等元素。囊壳的表面形态是不规则的,不宜作为分类依据。     

糙纹囊裸藻卵圆变种囊壳的微细结构及元素组成分析

囊裸藻属(Trachelomonas)的经典分类仍然是以囊壳的形状、大小、表面纹饰、领的形态为依据1,Pringsheim在培养的条件下研究了44个分类单位的囊裸藻,提出了依据原生质体进行分类的观点2,得到许多学者的赞同。近年来,许多学者利用扫描电镜、透射电镜、X-射线、微电子衍射等现代手段对囊裸藻的囊壳超微结构、元素组成及发育等进行了研究,探讨它们与系统分类的关系3-10.本文报道糙纹囊裸藻卵圆变种(Trachelomonas scabra var.ovata Playf.)囊壳的扫描电镜观察和元素组成分析的结果,为该属的系统分类提供资料。       

中国具囊壳裸藻类的新种类

本文报道了在我国首次发现的１３个具囊壳裸藻类的新种类,在它们之中隶属于囊裸藻属的有５个新变种;属于陀螺藻属的有８个新变种。     

囊裸藻属一新种?适

Species nova cum T. granulatopsi Shi congruens, sed a qua lorica ovata e fronte visa, obovata e latere visa, poro flagelli collo instructo distincta. Lorica ovata a fronte visa, antice angusta, postice late rotundata et plerumque inspissta, interdum caudato-papillata, obovata a latere visa, antice lata, postice angusta, brunnea vel fulva. Superficies loricae scabrosa, tuberculis irregularibus et punctis sparsis instructa (lorica per microscopum electronicum visa e granis composita). Porus flagelli collo recto vel paulo obliquo antice paulo angusto margine planiusculo instructus. Flagellum longitudine loricam aequans vel ea paulo longius. Lorica 23.5～24 μm longa, 16～18 μm lata, 12～14 μm crassa; collum 3～4 μm altum, parte angusta circa 3 μm latum, parte basilari 4～4.5 μm latum, poro colli circa 3 μm diam.     

囊裸藻属一新种

异形囊裸藻　新种　图 1 ,图 2ＴｒａｃｈｅｌｏｍｏｎａｓｈｅｔｅｒｏｍｏｒｐｈａＱ .Ｘ .Ｗａｎｇ ,ｓｐ .ｎｏｖ .Ｆｉｇ.1 ,Ｆｉｇ.2图 1　异形囊裸藻　 1 .正面观 ;2 .顶面观 ;3 .侧面观。Ｆｉｇ .1　ＴｒａｃｈｅｌｏｍｏｎａｓｈｅｔｅｒｏｍｏｒｐｈａＱ .Ｘ .Ｗａｎｇ　 1 .Ｆｒｏｎｔｖｉｅｗ ;2 .Ｔｏｐｖｉｅｗ ;3 .Ｓｉｄｅｖｉｅｗ .ＳｐｅｃｉｅｓｎｏｖａｃｕｍＴ .ｇｒａｎｕｌａｔｏｐｓｉＳｈｉｃｏｎｇｒｕｅｎｓ,ｓｅｄａｑｕａｌｏｒｉｃａｏｖａｔａｅｆｒｏｎｔｅｖｉｓａ,ｏｂｏｖａｔａｅｌａｔｅｒｅｖｉｓａ,…     

中国囊裸藻属的新种类

1．旋转囊探藻网纹变种新变种图1：1TrachelomonasvolvocinaEhrenbergvarreticulataShi,var．nov．囊壳圆球形;表面具不规则的网纹。鞭毛孔无加厚环,具一低领。囊壳直径约16μm湖北：武汉,采于鱼池中,197310,31,李尧英采,图1：1（模式图,Iconotypus）本变种与原变种的     

哈尔滨产几种囊裸藻扫描电镜观察

本文采用扫描电子显微镜对采自哈尔滨市郊的囊裸藻属(Tra-chelomonas)12种5变种进行观察,其中有中国新记录5种3变种,东北新记录5种1变种。文中对每个种进行了形态描述并附有照片,认为应用扫描电子显微镜观察囊壳的表面结构,对此属的系统分类研究有重要意义。     

鄂西地区裸藻的新种类

本文报道的是1981年5—6月在鄂西地区(包括五峰、宜都、宜昌、当阳、兴山及神农架林区)采集到的裸藻门植物5个新种,7个新变种和3个新变型。       

Fine Structure and Biomineralization of the Mucilage in Envelopes of Trachelomonas lefevrei (Euglenophyceae)1

Envelope development in Trachelomonas lefevrei (Deflandre) begins with the production of short, coarse mucilaginous strands, morphologically similar to the mucilage produced by non-enveloped euglenoids. These initial mucilaginous secretions subsequently become impregnated with manganese (Mn) and/or iron (Fe). Continued mucilage secretion and mineralization results in a mature envelope that is characteristic for the species. When these mature envelopes are treated with oxalic acid to remove the Mn and Fe, the envelopes collapse and are composed only of short, coarse mucilaginous strands similar to those present during early stages of development, prior to their mineralization. Brief treatment with 10 mM EDTA renders dark envelopes colorless, and our EM-EDS analyses show that this corresponds to a loss of Mn from the envelope; however, if Fe is present in the envelope, it is unaffected by the brief treatment. The mucilage present during early stages of envelope development and that remaining after complete demineralization is also morphologically similar to the mucilage in the plug at the anterior end of the envelope.     

Tracing Patterns of Chloroplast Evolution in Euglenoids: Contributions from Colacium vesiculosum and Strombomonas acuminata (Euglenophyta)

The chloroplast genomes of two photosynthetic euglenoids, Colacium vesiculosum Ehrenberg (128,889 bp), and Strombomonas acuminata (Schmarda) Deflandre (144,167 bp) have been sequenced. These chloroplast genomes in combination with those of Euglena gracilis, Eutreptia viridis, and Eutreptiella gymnastica provide a snapshot of euglenoid chloroplast evolution allowing comparisons of gene content, arrangement, and expansion. The gene content of the five chloroplast genomes is very similar varying only in the presence or absence of, rrn5, roaA, psaI, psaM, rpoA, and two tRNAs. Large gene rearrangements have occurred within the C. vesiculosum and S. acuminata chloroplast genomes. Most of these rearrangements represent repositioning of entire operons rather than single genes. When compared with previously sequenced genomes, C. vesiculosum and S. acuminata chloroplast genomes more closely resemble the E. gracilis chloroplast genome in size of the genome, number of introns, and gene order than they do those of the Eutreptiales. Overall, the chloroplast genomes of these five species show an evolutionary trend toward increased intron number, a decrease in gene density, and substantial rearrangement of gene clusters.     

Comparative Study of the Elemental Composition of Vegetative and Resting Microbial Cells

X-ray microanalysis showed that vegetative cells, viable resting forms, and nonviable forms (micromummies) of the bacteria Bacillus cereus and Micrococcus luteus and the yeast Saccharomyces cerevisiae differ in the content of elements S, P, Ca, and K and Ca/K and P/S ratios. Viable resting forms (cystlike refractive cells and bacillar endospores) had more calcium and less phosphorus and potassium than vegetative cells, the difference being higher for bacilli than for micrococci and yeasts. The distinctive feature of all viable resting microbial forms was their low P/S ratios and high Ca/K ratios. The differences revealed in the cellular content and ratios of elements probably reflect changes in ionic homeostasis accompanying the transition of vegetative microbial cells to the dormant state. Relevant potassium parameters indicate that the membranes of viable resting forms retain their barrier function. At the same time, the nonviable micromummies, even those morphologically intact, of B. cereus and S. cerevisiae exhibited an anomalously low content of potassium, while those of M. luteus had an anomalously high content of this element. This suggests that the cellular membranes of micromummies lose their barrier function, which results in a free diffusion of potassium ions across the membranes. The possibility of using the elemental composition parameters for the quick analysis of the physiological state of microorganisms in natural environments is discussed.     

Elemental Composition of Extremely Alkaliphilic Anaerobic Bacteria

The contents of several chemical elements were assessed in the haloalkaliphilic acetogenic bacterium Natroniella acetigena and the alkaliphilic sulfate-reducing bacterium Desulfonatronum lacustre using X-ray microanalysis, stereoscanning microscopy, and mass spectrometry. The organisms were found to differ significantly in their relative contents of S, K, P, and Cl. The P/S ratio in cells of the alkaliphilic bacteria incubated in mineral media at different pH was pH-dependent. With a pH increase from 9 to 10, potassium extrusion from cells was observed, suggesting that secondary K⁺/H⁺ antiport activity accounts for the homeostasis of cytosolic pH. Deenergization of bacterial cells in the presence of inhibitors and ionophores results in specific changes in the P/S ratio, which may be considered an indicator of the cell energetic state. In Natroniella acetigena, the content of intracellular Cl was directly proportional to the NaCl concentration in the medium. Some metals were shown to be necessary for the N. acetigena viability; the requirement for Ni and Co was absolute. Although little demand for Mg was characteristic of the bacteria studied, their growth was stimulated by an increase in Mg concentration, and the cell resistance to lysis was enhanced.     

A taxonomic and ultrastructural study of Trachelomonas Ehr. (Euglenophyta) from subtropical Argentina

Fifty-four loricated euglenophyta taxa sampled in the province of Chaco, Argentina, belonging to the genus Trachelomonas Ehr., have been examined by means of scanning electron microscopy. On the basis of these observations three new varieties are proposed: T. oviformis van duplex, T. robusta var. sparsiornata and T. Sydneyensis var. acuminata. Several details of the lorica ultrastructure are illustrated.     

Fine Structure of Trichomitus batrachorum (Perty)*

SYNOPSIS. Trichomitus batrachorum (Perty) shares with Trichomonadinae most of its fine-structural characteristics, especially those pertaining to the undulating membrane that consists of a high body fold, enclosing the loop-shaped, periodic marginal lamella, and of the recurrent flagellum applied to the fold. This flagellate has also certain structures, i.e. the costal base, comb-like organelle, and well developed marginal lamella, in common with Monocercomonas. It shares with Hypotrichomonas the costal base; large pelta; very fine fibers perpendicular to, and connecting the axostylar microtubules; structural details of the most proximal segment of the marginal lamella; and general relationships between dorsal body fold (poorly developed in Hypotrichomonas) and the recurrent flagellum. All these electronmicroscopic findings support the crucial position of Trichomitus in the evolutionary sequence Monocercomonas→Hypotrichomonas→Trichomitus→ Trichomonadinae suggested previously by lightmicroscopic observations. Further, Trichomitus shares with all Tritrichomonadinae the comb-like structure, not found either in Hypotrichomonas or Trichomonadinae; and it has in common with Tritrichomonas also the costa with Type A periodicity, being the only member of Trichomonadinae with this type of supporting organelle. It appears, therefore, that Trichomitus-type organisms represent an important link in the evolution of all Trichomonadidae from Monocercomonadidae.     

The Fine Structure of Haemoproteus columbae Sporozoites*

SYNOPSIS. The fine structure of Haemoproteus columbae sporozoites has been studied and compared to sporozoite structure as revealed by the light microscope. The sporozoites are ultrastructurally similar to those of other Haemosporidia in that they possess a 3-layered pellicle, subpellicular microtubules, polar ring, micropore, free ribosome-like particles, micronemes, a structure resembling a Golgi complex, an irregular mitochondrion, and a large nucleus. In the anterior region of the sporozoite there are 21–22 regularly arranged longitudinal subpellicular microtubules located peripherally around the cell. In the apical region the microtubules appear thickened on 1 side. The sporozoite of H. columbae has a microneme system in which 1–3 micronemes are associated with the outer pellicular membrane at the anterior end. Micronemes are found throughout the cytoplasm, but occur in greater concentration in the anterior region of the sporozoite. A clear pellicular cavity, located between the polar ring and the termination of the inner pellicular layer, is present at the anterior end of the sporozoite. Vesicular invaginations of the inner pellicular layer have been observed in the anterior region; their function is unknown. Spherical osmophilic bodies are found throughout the cytoplasm.     

瘤棘砂壳虫(肉足亚门:根足总纲)壳体元素组成

利用X射线能谱仪对采自中国湖北省木兰湖的瘤棘砂壳虫(Diffugia tuberspinifera)壳体元素组成进行分析,结果发现：构成壳体的化学元素主要为Si,其次是Ca和Al,还有微量K、Na、Cl、Fe、Mg、S和P。分析表明瘤棘砂壳虫壳体化学元素的构成介于海洋和土壤有壳肉足虫之间。