Showing papers in "Archives of Microbiology in 1970"
TL;DR: Five mutant strains of Hydrogenomonas H 16 which synthesize poly-β-hydroxybutyric acid either slowly or not at all have been isolated following nitrite and NMG treatment of wild type cells.
Abstract: Five mutant strains of Hydrogenomonas H 16 which synthesize poly-β-hydroxybutyric acid either slowly or not at all have been isolated following nitrite and NMG treatment of wild type cells. When grown on a nitrogen deficient agar medium, the colonies of PHB-free cells can be recognized by their diminished retention of the dye sudanblack B. Enrichment procedures for such mutants have been devised employing the 32P-phosphate inactivation technique and sucrose gradient centrifugation. The mutants have been characterized with respect to their growth properties, respiratory control and other properties.
302 citations
TL;DR: The pigments have been identified and quantitatively determined by methods discussed in Hager and Stransky (1970) and based on the occurring pigments, the xanthophyll cycle of Isochrysis is identical with that of the Xanthophycee, Euglenophyceae and Diatomeae.
Abstract: Die Pigmente wurden nach den bei Hager u. Stransky (1970) besprochenen Methoden identifiziert und ihre Mengen bestimmt.
236 citations
TL;DR: The non-heterocystous filamentous blue-green alga, Plectonema boryanum strain 594 reduces acetylene to ethylene, incorporates 15N2 into cell protoplasm, and grows readily in medium free of combined nitrogen, when incubated in a gas phase without added oxygen.
Abstract: The non-heterocystous filamentous blue-green alga, Plectonema boryanum strain 594 reduces acetylene to ethylene, incorporates 15N2 into cell protoplasm, and grows readily in medium free of combined nitrogen, when incubated in a gas phase without added oxygen. Cells grown in the presence of 50 mg/l of ammonium-nitrogen do not reduce acetylene, and a concentration of 0.015 atm. CO in the gas phase inhibits nitrogenase activity completely but inhibits 14CO2 incorporation by only 28%. Nitrogenase activity is inhibited after 2 h treatment with 3×10-5 M DCMU and is inhibited completely in air.
188 citations
TL;DR: A new species—Clostridium formicoaceticum—is described, which ferments fructose and several hexonic and hexuronic acids to acetate and formate and differs from C. aceticum in its inability to grow on hydrogen plus carbon dioxide.
Abstract: A new species—Clostridium formicoaceticum—is described. It ferments fructose and several hexonic and hexuronic acids to acetate and formate. During active growth acetate is the main product of the fermentation. Considerable quantities of formate appear among the fermentation products in the stationary growth phase.
139 citations
TL;DR: The relative changes in cell density and dry weight and in the content of different macromolecules during the budding cycle suggest a cyclic change between utilization of endogenous and exogenous substrates.
Abstract: A simple and rapid method for obtaining synchronously budding cultures of Saccharomyces cerevisiae is described. Synchronous cultures were started with homogeneous cell fractions isolated from exponentially growing cultures by isopycnic centrifugation in osmotically inactive media. The technique of fractionation is based on changes of cell density throughout the budding cycle. These changes are correlated with vacuolar changes observed in the light and electron microscope. During bud initiation the large vacuoles in late budding cells shrink and fragment into small vacuoles. Simultaneously the density of the cells increases. Later stages of the budding cycle are characterized by the distribution of the small vacuoles between mother and daughter cell, followed by their fusion and expansion, and by a decreasing density of the cells. The relative changes in cell density and dry weight and in the content of different macromolecules during the budding cycle suggest a cyclic change between utilization of endogenous and exogenous substrates. This is discussed in terms of a cyclic consumption and accumulation of vacuolar pools.
104 citations
TL;DR: Cell-free extracts capable of acetylene reduction and cyanide reduction have been prepared from heterocystous and non-heterocyStous blue-green algae and the extracts are cold labile and highly sensitive to oxygen and the oxygen inhibition is irreversible.
Abstract: Cell-free extracts capable of acetylene reduction and cyanide reduction have been prepared from heterocystous (Anabaena cylindrica) and non-heterocystous (Plectonema boryanum 594) blue-green algae. Extracts from Anabaena were obtained from cultures grown in blulk under aerobic conditions, while the Plectonema cultures were grown in bulk on nitrate-nitrogen, then washed free from nitrate and sparged with A/CO2 for 40 h after which time maximum nitrogenase activity was detected. The nitrogenases of both algae are similar and resemble in many respects nitrogenases from bacteria and legumes. Activity is located primarily in a 40,000xgx15 min supernatant fraction and the rate of C2H2 reduction observed is about 10 per cent of whole cell activity. ATP and a source of reducing power (Na2S2O4) are required for efficient functioning of the enzyme. ATP-dependent hydrogen evolution occurs, the extracts are cold labile and highly sensitive to oxygen and the oxygen inhibition is irreversible.
99 citations
TL;DR: Two new species of Pseudomonas are described: one, a yellow-pigmented hydrogen bacterium, P. palleronii Davis; the other, a non-autotrophic, non- pigmented species,P.
Abstract: The properties of several named and unnamed strains of polarly flagellated “hydrogen bacteria” are described and compared with those of related autotrophic and non-autotrophic species Two new species ofPseudomonas are described: one, a yellow-pigmented hydrogen bacterium,P palleronii Davis; the other, a non-autotrophic, non-pigmented species,P delafieldii Davis
88 citations
TL;DR: Comparative studies have been carried out on the amino acid composition of the bulk protein of the two main types of extremely halophilic bacteria and their non-halophilic, bacteriological counterparts, finding the protein of all the extreme halophiles tested was relatively high in aspartic and glutamic acids and low in lysine and alanine.
Abstract: Comparative studies have been carried out on the amino acid composition of the bulk protein of the two main types of extremely halophilic bacteria and their non-halophilic, bacteriological counterparts. The protein of all the extreme halophiles tested was relatively high in aspartic and glutamic acids and low in lysine and alanine. The results have furnished a basis for a discussion of the molecular mechanisms which might be involved in the evolution of an extremely halophilic organism from a non-halophilic organism.
86 citations
TL;DR: The fine structure of honey-coloured, sessile Endogone spores is described from initiation of the mother spore to dormancy of the resting spore as mentioned in this paper, and three unusual organelles occur viz. pigment granules, large crystals and self-duplicating bacteria-like organisms.
Abstract: The fine structure of honey-coloured, sessile Endogone spores is described from initiation of the mother spore to dormancy of the resting spore. Three unusual organelles occur viz. pigment granules, large crystals and selfduplicating bacteria-like organisms. The first two are very numerous, and are specifically associated with spore formation. The pigment granules are involved in the deposition of the honey-coloured wall, and change into myelin-like figures when cytoplasm moves from the mother into the resting spore. The crystals, whose function is not known, are most conspicuous just before the resting spore reaches dormancy. The bacteria-like organisms, which may be actinomycete spores living symbiotically in the fungus, multiphy greatly as the spore enters dormancy. The dormant spore contains very little cytoplasm compressed into a fine network between very large polygonal oil globules and large round bodies thought to contain a storage polysaccharide.
82 citations
TL;DR: The ability to decompose choline is widespread among aerobic microorganisms since representatives of the genera Agrobacterium, Arthrobacter, Micrococcus, Pseudomonas, Rhizobium, and Streptomyces and a large number of coryneform bacteria were found to grow with choline as the sole C-and N-source as discussed by the authors.
Abstract: 1.
The ability to decompose choline is widespread among aerobic microorganisms since representatives of the genera Agrobacterium, Arthrobacter, Micrococcus, Pseudomonas, Rhizobium, and Streptomyces and a large number of coryneform bacteria were found to grow with choline as the sole C- and N-source.
2.
Almost all the coryneforms isolated from soil and dairy waste activated sludge displayed this ability in contrast to those isolated from cheese and, be it to a less extent, those from the phyllosphere. The significance of choline utilization in the taxonomy of coryneform bacteria is discussed.
3.
All the choline-utilizing bacteria tested were found to be able to grow with betaine, N,N-dimethylglycine, or sarcosine as the sole C- and N-source. Choline-grown cells, as contrasted to those grown with yeast extract and glucose, of Pseudomonas fluorescens and Arthrobacter S3 respired the latter three compounds at a rate similar to that of choline.
4.
About 30% of the 50 choline-utilizing coryneform bacteria tested grew also with N,N-dimethylethanolamine and N-monomethylethanolamine. Choline-grown cells, in contrast to those grown with yeast extract and glucose, of a representative of this group, Arthrobacter S3, also respired these two compounds at a rate somewhat lower than that of choline.
81 citations
TL;DR: The lipopolysaccharide has a very low phosphate content and does not contain heptose, it shows low pyrogenicity in rabbits and it is not toxic in mice.
Abstract: A lipopolysaccharide was isolated from cell walls of Anacystis nidulans by extraction with 45% aqueous phenol at 65°, and further purified by repeated high speed centrifugation. It contains 30–40% of lipid and about 60% of carbohydrate components. The carbohydrate moiety contains predominantly mannose and smaller amounts of galactose, glucose, fucose, rhamnose, 2-keto-3-deoxyoctonate, glucosamine and a second aminosugar. The latter was identified as a 2-amino-2-deoxyheptose with the gluco-configuration from C3 to C7. Thelipid moiety contains glucosamine and fatty acids (C22:0, C18:2, C16:0, C12:0 and C14:βOH). The lipopolysaccharide has a very low phosphate content and does not contain heptose. It shows low pyrogenicity in rabbits and it is not toxic in mice.
TL;DR: It is proposed that the marine isolate be considered a new species and that it be named Spirochaeta litoralis.
Abstract: A strictly anaerobic spirochete was isolated from a sample of marine mud. The organism possessed two axial fibrils entwined with the regularly coiled protoplasmic cylinder. An outer envelope or sheath enclosed both protoplasmic cylinder and axial fibrils. The spirochete grew in chemically defined media containing glucose, amino acids or NH4Cl, sulfide, NaCl, vitamins, coenzyme A, and in-organic salts. A reducing agent, such as sodium sulfide or l-cysteine, as well as exogenous supplements of biotin, niacin and coenzyme A were required for growth. Pantothenate replaced coenzyme A as an exogenous growth factor, but the resulting cell yields were low. The spirochete grew in media prepared with sea water, but not in fresh water media containing less than 0.05 M NaCl (optimum concentration 0.35 M). Both Na+ and Cl- were required. Carbohydrates served as fermentable substrates. Amino acids, sugar alcohols, tricarboxylic acid cycle intermediates, and other organic acids and alcohols were not fermented. Glucose was fermented to ethyl alcohol, acetate, CO2, H2, and small amounts of lactate, formate and pyruvate. The guanine + cytosine content of the DNA of the spirochete was 50.5 moles-% (buoyant density). It is proposed that the marine isolate be considered a new species and that it be named Spirochaeta litoralis.
TL;DR: In this article, the parent and resting spores of an Endogone sp. with honey-coloured, sessile spores are described and the structure and development of the multi-layered wall of the mature resting spore are described.
Abstract: Wall structure is described in the parent and resting spores of an Endogone sp. with honey-coloured, sessile spores. Wall thickness increases in the parent spore and subtending hypha by passage of material through the plasmalemma, or by formation of an apparently separate inner wall and degeneration of the trapped cytoplasm. Structure and development of the multi-layered wall of the mature resting spore are described. Unusual features are: 1. the incorporation of many pigment granules into the coloured outer wall, 2. the presence between the outer coloured and inner transparent walls of a tripartite membrane and adjacent layer with a regular periodicity and 3. a sectored layer with a crystalline component. The structure of the wall is discussed with reference to that of other mucoraceous fungi, to spore germination and to the mechanism of wall formation.
TL;DR: The vesicles in crude extracts are unstable upon storage; they rapidly lose their characteristic structure, accompanied by a destruction of bacteriochlorophyll, and can be prevented by brief treatment of extracts with glutaraldehyde.
Abstract: The particulate fraction in cell-free extracts of three Chlorobium strains was examined. It contains two structural components: membrane fragments and chlorobium vesicles. These two components have been separated, and certain of their properties compared. Both consist largely of lipid and protein. The lipids of the membrane fraction are predominantly phospholipids, but include a glycolipid which contains galactose, rhamnose and an unidentified sugar. The vesicles are highly enriched in bacteriochlorophyll, and contain large amounts of a monogalactosyl diglyceride; their content of phospholipid is low. All the succinic and malic dehydrogenase activity of the particulate fraction is located in the membranes, whereas NADH- and NADPH-linked dye reductases occur in both membranes and vesicles. The vesicles in crude extracts are unstable upon storage; they rapidly lose their characteristic structure, accompanied by a destruction of bacteriochlorophyll. These changes can be prevented by brief treatment of extracts with glutaraldehyde. Many of the isolated vesicles contain from 10 to 25 regular intravesicular structures, which are about 10 nm wide and circular, with a central hole 3 nm in diameter.
TL;DR: The radius of Aspergillus nidulans pellets grown singly (i.e. l/flask) increased linearly with time for most or all of their growth; they grew at about half the rate of colonies of the mould upon solid medium as mentioned in this paper.
Abstract: 1.
The radius of Aspergillus nidulans pellets grown singly (i.e. l/flask) increased linearly with time for most or all of their growth; they grew at about half the rate of colonies of the mould upon solid medium. The final pellet diameter, the duration of the linear growth phase and the initial radial growth rate decreased as the pellet concentration was increased.
2.
Single pellets initially increased in dry weight at an exponential rate; the specific growth rates at 20°, 25° and 30°C but not at 37°C were almost identical with the organism's maximum specific growth rates at these temperatures.
3.
The cube root of the dry weight of pellets grown singly also increased linearly with time for most or all of their growth, but a smaller proportion of the total growth of cultures inoculated with several pellets was of this form. Cube root kinetics were only maintained as long as the pellets grew at a constant rate.
4.
When Aspergillus nidulans cultures were inoculated with various conidial concentrations the ratio, conidia per flask: pellets formed per flask, varied between 2–6×104. Cultures only grew at the maximum specific growth rate when inoculated with at least 6×105 conidia/ml of medium.
TL;DR: Field observations of the natural habitats, the temperature maximum for 14CO2 incorporation of natural populations, and the temperaturemaximum for the growth of cultures of Cyanidium caldarium indicate that the upper temperature limit for C. cald aquarium is 55–60°C, which is not compatible with the description of C.caldarium as an extreme thermophile.
Abstract: Field observations of the natural habitats, the temperature maximum for 14CO2 incorporation of natural populations, and the temperature maximum for the growth of cultures of Cyanidium caldarium indicate that the upper temperature limit for C. caldarium is 55–60°C. These results are not compatible with the description of C. caldarium as an extreme thermophile.
TL;DR: In this paper, auffallende Naturerscheinungen, e.g., Blutregen and Blutschnee, are verursacht werden in der Hauptsache durch Massenvorkommen von Aplanosporen der volvocalen Grunalgen Haematococcus pluvialis and Chlamydomonas nivalis verursach werde.
Abstract: “Blutregen” und “Blutschnee” sind zwei auffallende Naturerscheinungen, die in der Hauptsache durch Massenvorkommen von Aplanosporen der volvocalen Grunalgen Haematococcus pluvialis und Chlamydomonas nivalis verursacht werden. Die fur die rote Farbe verantwortlichen Pigmente sind Keto-Carotinoide. Die Versuche zeigen, das auch unter naturlichen Bedingungen fur die Biosynthese dieser Polyene und fur den gleichzeitig ablaufenden Abbau der Chlorophylle Stickstoffmangel der entscheidende Faktor ist.
TL;DR: A method involving penicillin treatment was developed to osmotically lyse the cells of the blue-green alga, Microcystis aeruginosa Kuetz, and release the pressure-sensitive gas vacuoles intact.
Abstract: A method involving penicillin treatment was developed to osmotically lyse the cells of the blue-green alga,Microcystis aeruginosa Kuetz. emend. Elenkin, and release the pressure-sensitive gas vacuoles intact. The gas vacuoles were purified by liquid-polymer partitioning or by macromolecular sieving and centrifugation. The degree of purification of the gas vacuoles was followed by observation in the electron microscope and by the use of C14-labeled vacuolated and nonvacuolated strains ofM. aeruginosa. The gas-vacuole membrane is composed of only protein consisting of 10% basic, 18% acidic and 52% non-polar amino acids.
TL;DR: From water of the Baltic Sea a bacterium has been isolated which reproduces by budding and by multiple fission of coccoid units, thus giving rise to a variety of cell forms and aggregates which so far have not been known in any bacterial genus.
Abstract: Aus Wasser der Ostsee wurde ein Bakterium isoliert, das durch Knospung sowie durch Mehrfachteilung kokkenahnlicher Einheiten eine Vielfalt von Zellformen und-aggregaten ausbildet, wie sie bisher in keiner Bakteriengattung bekannt sind. Es handelt sich um einen heterotrophen beweglichen grampositiven Brackwasserorganismus. Die vorliegende Arbeit behandelt morphologische, cytologische und physiologische Merkmale sowie die mogliche taxonomische Stellung des Organismus.
TL;DR: Hyphal walls of Apodachlya sp.
Abstract: Hyphal walls of Apodachlya sp. (Leptomitales) gave a positive reaction when tested cytochemically for chitin. The color reaction indicative of the presence of chitin developed uniformly throughout the walls, but did not appear in the numerous cellulin granules found in this fungus. Chitin and cellulose fractions were prepared from chemically isolated walls and identified by X-ray diffraction.
TL;DR: Comparison of algal populations tested showed that in the test medium used Cladophora glomerata was the most or almost the most sensitive to all three metals.
Abstract: A survey was carried out of the toxicity of zinc, copper and lead to Chlorophyta from flowing waters. 20 populations each of Stigeoclonium tenue and Cladophora glomerata were tested to see whether any variation in metal resistance could be found in natural populations. The only such indication found was of a slight increase in resistance to zinc of one Stigeoclonium population from a metal-polluted stream. 35 other algal populations, representing about 25 species, were also tested. Comparison of all these populations showed that in the test medium used Cladophora glomerata was the most or almost the most sensitive to all three metals. The Ulotrichales and most of the Zygnemales were relatively resistant to zinc, while all the Oedogonium spp. taken from the field were sensitive to zinc. However, an Oedogonium population highly resistant to zinc was obtained from a zinc enriched laboratory tank.
TL;DR: Experiments with C14-labelled glucose have shown that the inability to utilize glucose at 80° C is not due to an inactivation of the initial steps of the glycolytic pathway, thus blocking the utilization of glucose at this temperature.
Abstract: Conditions for cultivating two extremely thermophilic bacteria, isolated from the hot springs of Yellowstone National Park, are described. One of these strains, Thermus aquaticus, can be grown on either succinate or pyruvate as the best substrates at 78° C. Acetate, glucose, and sucrose can also be utilized at this temperature. The temperature optimum was found to be 70° C, but the bacterium can be adapted to grow on succinate or pyruvate at 80° C. The other strain, YT-G has its growth optimum at 80° C and the maximum temperature was found to be 84° C. At this temperature pyruvate is the only substrate which gives good results, while glucose cannot be used as a carbon source. At 70° C, however, the yields obtained with glucose as a substrate are better than those with pyruvate at 80° C. Experiments with C14-labelled glucose have shown that the inability to utilize glucose at 80° C is not due to an inactivation of the initial steps of the glycolytic pathway. Phosphorylated sugars and a compound corresponding to α-glycerophosphate were found to be formed, the latter being accumulated as a side product of normal glycolysis. The enzymes leading to this product, and those which are involved in the conversion of pyruvate were found to be functioning at 80° C, while intermediate enzymes of the glycolytic pathway are assumed to be less heat resistant, thus blocking the utilization of glucose at this temperature. The ability of strain YT-G to grow on glucose is, however, promptly resumed if the temperature is lowered. Lysozyme treatment was found to lead to a complete conversion of T. aquaticus cells to spheroplast while cells of strain YT-G are only slightly altered by this procedure.
TL;DR: Electron micrographs of the early stages in microsclerotial development in v. dahliae Kleb showed that hyphae became swollen and vacuolate and extruded melanizing particles into the interhyphal spaces of the microsclerosis.
Abstract: Electron micrographs of the early stages in microsclerotial development in v. dahliae Kleb. showed that hyphae became swollen and vacuolate and extruded melanizing particles into the interhyphal spaces of the microsclerotium. Peripheral microsclerotial cells were killed either by a process of autoparasitisation from adjacent hyphae or by autolysis. Variations in the thickness of the melanized material surrounding cells gave the superficial appearance of variations in cell wall thickness between individual cells though actual changes in cell wall thickness were not observed.
TL;DR: It is suggested, that a non-specific enzyme sequence of the meta cleavage pathway is induced by all of these phenols, which can catalyze the oxidation of phenol and its analogues to pyruvate, a fatty acid and a carbonyl compound, according to the general scheme of Dagley et al. (1964).
Abstract: The oxidation of several mono-hydric phenols by wild type and mutant strains of Pseudomonas aeruginosa T1 has been studied. The data suggest, that a non-specific enzyme sequence of the meta cleavage pathway is induced by all of these phenols, which can catalyze the oxidation of phenol and its analogues to pyruvate, a fatty acid and a carbonyl compound, according to the general scheme of Dagley et al. (1964). Mutants unable to grow on phenol (hydroxylase-negative), have been isolated, and they are also unable to grown on or oxidize the cresols and the xylenols. Revertants of these mutants regain the capacity to grow on all these phenols and are indistinguishable from the wild type. Induced-substrate relationships for the earlier enzymes of the pathway have been determined, e.g., phenol in addition to catechol and the methylcatechols is an inducer for catechol 2,3-oxygenase. Analysis of the enzymic content of cells grown in a variety of steadystate conditions shows (a) that the ratio of the specific activities of the “phenol” hydroxylase and catechol 2,3-oxygenase is constant for each of their analogous substrates; and (b) that induction and catabolite repression of catechol 2,3-oxygenase and the “muconic semialdehyde” hydrolyase are coordinate, but that control of the “phenol” hydroxylase is independent.
TL;DR: A model is presented which accounts for the proportion of cells induced into synchronous genome replication which is also related to the state of replication at the onset of pre-synchrony treatment.
Abstract: Following the induction of synchronous growth of Anacystis nidulans by light and CO2 deprivation, cell mass and RNA and DNA content during two cell cycles were measured. Both RNA and DNA synthesis were discontinuous and marked variation in survival to ultraviolet light was related to the state of replication. A model is presented which accounts for the proportion of cells (66%) induced into synchronous genome replication which is also related to the state of replication at the onset of pre-synchrony treatment.
TL;DR: A complex system of growth inhibition is present in the green algae (Volvocaceae).
Abstract: A complex system of growth inhibition is present in the green algae (Volvocaceae). Inhibitors are found in the culture filtrates of some genera which limit their own growth (autoinhibition) while others in the family produce inhibitors which check the growth of other genera (heteroinhibition). These inhibitors are destroyed by autoclaving.
TL;DR: The content of deoxyribonucleic acid was the same in coccolith-forming and naked cells, suggesting that they do not represent different phases in a sexual lifecycle.
Abstract: In a naked clone of the coccolithophorid Coccolithus huxleyi, growth at light saturation was 15% slower than in a coccolith-forming clone isolated from the same parent stock The two cell types did not differ significantly with regard to cell volume and protein content A 10–13% smaller chlorophyll a content of the naked cells was matched by a uniform lowering of photosynthetic rates at all light intensities It was considered that the slower growth of these cells might result from a less favourable ratio between photosynthetic output and biomass
TL;DR: The Thylakoide is a Thylakoid associated with the Chloroplasten and Pyrenoide of Cryptophyceae as mentioned in this paper, and is a type of thylakoids.
Abstract: 1
Die Feinstruktur der Chloroplasten und Pyrenoide von je einer Art der Gattungen Cryptomonas, Chroomonas und Hemiselmis (Cryptophyceae) wurden elektronenmikroskopisch untersucht
2
Die Thylakoide sind locker assoziiert, hauptsachlich zu zweit, und durch einen geringen Abstand von 30–80 A getrennt Ein Thylakoid kann fur eine langere Strecke mit ein und demselben Thylakoid assoziiert sein oder im Wechsel mit zwei auf gegenuberliegenden Seiten verlaufenden Thylakoiden Thylakoidgabelungen wurden in allen 3 Arten beobachtet
3
Abweichend von allen bekannten Chloroplasten sind die Thylakoide der hier untersuchten Cryptophyceen kontrastreich; sie enthalten im intrathylakoidalen Raum (=Loculus im Sinne von Weier, 1962) verteilt ein fein granuliertes, dichtes Material Bedingt durch eine ungleiche Verteilung dieses intrathylakoidalen Materials wechselt die Dicke der Thylakoide im Bereich von 190–300 A bei Cryptomonas und von 240–360 A bei Hemiselmis und Chroomonas; keulenformige Endglieder der Thylakoide konnen diese Werte noch ubertreffen
4
Ribosomenahnliche Partikel von 120–180 A Durchmesser, Vacuolen und verstreut vorkommende, elektronentransparente DNS-fuhrende Bezirke wurden in der Chloroplastenmatrix beobachtet, jedoch konnte keine Granulafraktion entdeckt werden, die in enger Bindung an die Oberflachen der Thylakoidmembranen den Biliproteinpartikeln von Rhodophyceen und Cyanophyceen entsprechen wurde
5
Die gestielten Pyrenoide von Hemiselmis und Chroomonas entspringen dem Vorderende des bootformigen Chloroplasten und werden von einem Thylakoidpaar durchzogen In Cryptomonas nimmt das Pyrenoid den zentralen Teil des H-oder U-formigen Chloroplasten ein und stellt damit einen Teil der Verbindung der beiden Lappen dar Gepaarte Thylakoide dringen bis in diese Brucke vor und enden in der Pyrenoidbasis Auf der freien Seite ist das Pyrenoid durch einen Spalt aufgeliedert, der das Stigma enthalt Die Pyrenoide werden von Starkekornern umgeben, die auserhalb der Chloroplastenhulle liegen, die jedoch ihrerseits zusammen mit dem Stigma und dem ganzen Chloroplasten von einer periplastidaren ER-Cisterne umschlossen werden, die gewohnlich mit der Kernhulle in Zusammenhang steht
TL;DR: In further studies of the zoosporic fungi of New Zealand nine additional species were isolated on various substrata from soil as mentioned in this paper, including Rhizophydium pythii de Wildemann, R. reniformis, Aphanomycopsis punctatus and R. boneysi.
Abstract: In further studies of the zoosporic fungi of New Zealand nine additional species were isolated on various substrata from soil. These include Rhizophydium pythii de Wildemann, R. condylosum Karling, Rhizophlyctis oceanis Karling, R. ingoldii Sparrow, R. boneysi Sparrow, Rhizophlyctis sp., Rhizidium reniformis sp. nov., Chytriomyces rotoruaensis sp. nov., Sparrowia parasitica Willoughby, and Aphanomycopsis punctatus Karling. Rhizidium reniformis is characterized by predominantly reniform, appendiculate zoosporangia and small zoospores which emerge slowly in a columnar mass. This usually floats away from the zoosporangium and explands, and after a while the zoospores swarm collectively in a vesicle. Chytriomyces rotoruaensis resembles R. reniformis by the structure and appearance of its thallus and behavior of the zoospores after discharge, but differs by the presence of a thin inconspicuous operculum and the development of smooth hyaline resting spores with coarsely granular content. Rhizophlyctis ingoldii, Sparrowia parasitica, and R. boneysi, known previously only from England and Hawaii, respectively, occurred abundantly in New Zealand.
TL;DR: Somatic cells of mature asexual colonies of Volvox carteri do not possess a true cell wall, but are otherwise similar in ultrastructure to Chlamydomonas as discussed by the authors.
Abstract: Somatic cells of mature asexual colonies of Volvox carteri do not possess a true cell wall, but are otherwise similar in ultrastructure to Chlamydomonas. Somatic cells are embedded in multilayered fibrillar material of the colonial matrix. The reproductive cells (gonidia) of Volvox carteri lie internal to the somatic cell layer of the colony matrix in an apparently structureless portion of the colony matrix. Mature gonidia are large vacuolate cells with a central nucleus and parietal chloroplasts and mitochondria. They are non-flagellated at maturity, but each contains a pair of kinetosomes.