The Effect of Light on the Developmental Cycle of Nostoc muscorum, a Filamentous Blue-Green Alga

Lazaroff, Norman; Vishniac, Wolf

doi:10.1099/00221287-25-3-365

Cited by 73 publications

(36 citation statements)

References 6 publications

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“…Dr J. W.G.Lund, who has kindly examined our material, has expressed the tentative opinion that it is a Nostoc (personal communication). This view is supported by the resemblance of the life-cycle of ChbrogZoea fritschii to that of No& rnwcorum as described by Lazaroff & Vishniac (1961). These authors reported an alternation of coccoid (' aseriate') and filamentous stages, successive cell divisions producing a cluster of cells surrounded by a membrane which later breaks down liberating the hormogonia.…”

Section: Ehects Of Mutagenic Agents On Growth and Nitrogen Jixationsupporting

confidence: 67%

Cellular Factors Affecting Nitrogen Fixation in the Blue-Green Alga Chlorogloea fritschii

Fay

Kumar

Fogg

1964

Journal of General Microbiology

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SUMMARYSynchronous cultures of a nitrogen-fixing blue-green alga, hitherto known as ChZorogZoeafi&chii but more probably an anomalous species of the genus Nostoc, were obtained by a combination of light and temperature treatments. Variation in dimensions, dry weight, pigment content and total nitrogen content of cells was followed during the development of synchronous cultures. The nitrogen-fixing activity was greatest in the small-celled filaments which develop from the endospores and predomhate during exponential growth of the alga in cultures of limited volume. Strains of the alga produced by repeated exposure to X-rays, ultraviolet radiation, or sublethal concentrations of co€chicine or urethane, were found to have lower rates of nitrogen fixation per unit dry weight than the original strain but liberated relatively more extracelIdar nitrogenous products.

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Section: Ehects Of Mutagenic Agents On Growth and Nitrogen Jixationsupporting

confidence: 67%

Cellular Factors Affecting Nitrogen Fixation in the Blue-Green Alga Chlorogloea fritschii

Fay

Kumar

Fogg

1964

Journal of General Microbiology

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“…On this basis, strains that produce non-heterocystous immotile hormogonia, either composed of smaller cells than the mature trichomes (PCC 6314, 7524) or containing gas vacuoles (PCC 6719), have been assigned to Nostoc. Although some Nostoc strains are said to divide in a plane parallel to the long axis of the trichome in the course of development (Bornet & Flahaut, 1888 b;Harder, 1917;Geitler, 1932;Lazaroff & Vishniac, 1961), we have never observed a change in the plane of division in any of the strains included in Nostoc. This observation is confirmed by the fact that none of the Nostoc strains forms lateral heterocysts.…”

Section: Genera Of Section IVmentioning

confidence: 82%

“…In their descriptions of Nostoc, Bornet & Flahaut (1888b) and Geitler (1932) imply that strains of this genus undergo a developmental cycle that is absent from Anabaena species. Furthermore, the developmental stages of numerous Nostoc species have been described in detail (Thuret, 1844;Sauvageau, 1897;Harder, 1917;Lazaroff & Vishniac, 1961 ;Mollenhauer, 1970). Nevertheless, the presence or absence of a developmental cycle has never been proposed as a discriminatory character.…”

Section: Genera Of Section IVmentioning

confidence: 99%

Generic Assignments, Strain Histories and Properties of Pure Cultures of Cyanobacteria

et al. 1979

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On the basis of a comparative study of 178 strains of cyanobacteria, representative of this group of prokaryotes, revised definitions of many genera are proposed. Revisions are designed to permit the generic identification of cultures, often difficult through use of the field-based system of phycological classification. The differential characters proposed are both constant and readily determinable in cultured material. The 22 genera recognized are placed in five sections, each distinguished by a particular pattern of structure and development. Generic descriptions are accompanied by strain histories, brief accounts of strain properties, and illustrations; one or more reference strains are proposed for each genus. The collection on which this analysis was based has been deposited in the American Type Culture Collection, where strains will be listed under the generic designations proposed here. I N T R O D U C T I O NThe cyanobacteria constitute one of the largest sub-groups of Gram-negative prokaryotes. As a result of their traditional assignment to the algae, the classification of these organisms was developed by phycologists, working under the provisions of the Botanical Code (Stafleu et al., 1972). Almost entirely on the basis of observations on field materials, about 150 genera and well over lo00 species have been described. The discriminatory properties, both generic and specific, are either structural or ecological, these being virtually the only characters determinable in the field. Types are represented by herbarium specimens or, failing these, by descriptions and illustrations; cultures are not recognized as valid type materials under the Botanical Code.The attempt to identify cyanobacteria in culture through this field-based system of classification leads to many difficulties and ambiguities. The limited and necessarily provisional taxonomic goal of the present article is to redefine certain cyanobacterial genera in such a way that simple and clear-cut generic assignments can be made for cultures. It is based on our experience over the past decade with pure strains representative of all major sub-groups of cyanobacteria. As far as possible, we have attempted to maintain the system of generic nomenclature and the generic definitions now used by phycologists (Bourrelly, 1970;Geitler, 1932;Desikachary, 1959). However, when the discriminatory characters that nominally distinguish two genera are either not determinable on cultures or within the range of variation of a single strain, the existing genera have been combined. Some of the proposed generic definitions include discriminatory characters that have not hitherto received taxo-

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“…In recent phylogenetic studies, using several molecular marker genes (small subunit rRNA, rpoB, rbcLX and nifD or nifH), the closest relatives to the genus Nostoc were shown to be the genera Anabaena, Aphanizomenon and Trichormus, also members of the family Nostocaceae (Rajaniemi et al, 2005;Svenning et al, 2005;Henson et al, 2002Henson et al, , 2004Lohtander et al, 2003). All members of the genus Nostoc are characterized by a complex life cycle that includes differentiation into heterocytes (nitrogen-fixing cells), akinetes (resting spores) and hormogonia (motile filaments), serving for dispersion and as infective units in symbiosis (Lazaroff, 1966;Lazaroff & Vishniac, 1961;Mollenhauer, 1970;Rippka et al, 1979). Four Nostoc groups, three of which corresponded to the type species Nostoc muscorum, Nostoc edaphicum and Nostoc calcicola, have been resolved on the basis of their life cycle (Hrouzek et al, 2003;Rajaniemi et al, 2005) but, following the analysis of 81 additional 16S rRNA gene sequences of cyanobacterial strains identified as belonging to the genus Nostoc, many more clusters were obtained.…”

Section: Introductionmentioning

confidence: 99%

Differential patterns of evolution and distribution of the symbiotic behaviour in nostocacean cyanobacteria

Papaefthimiou

Hrouzek

Mugnai

et al. 2008

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLO

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Many cyanobacteria commonly identified as belonging to the genus Nostoc are well-known cyanobionts (symbionts) of a wide variety of plants and fungi. They form symbioses with bryophytes, pteridophytes, gymnosperms and angiosperms that are considerably different in the type of reciprocal interaction between the host and the cyanobiont. The phylogenetic and taxonomic relationships among cyanobionts isolated from different hosts and Nostoc strains isolated from free-living conditions are still not well understood. We compared phylogeny and morphology of symbiotic cyanobacteria originating from different host plants (genera Gunnera, Azolla, Cycas, Dioon, Encephalartos, Macrozamia and Anthoceros) with free-living Nostoc isolates originating from different habitats. After preliminary clustering with ARDRA (amplified rDNA restriction analysis), phylogeny was reconstructed on the basis of 16S rRNA gene sequences and compared with morphological characterization, obtaining several supported clusters. Two main Nostoc clusters harboured almost all cyanobionts of Gunnera, Anthoceros and of several cycads, together with free-living strains of the species Nostoc muscorum, Nostoc calcicola, Nostoc edaphicum, Nostoc ellipsosporum and strains related to Nostoc commune. We suggest that the frequent occurrence of symbiotic strains within these clusters is explained by the intensive hormogonia production that was observed in many of the strains studied. However, no evidence for discrimination between symbiotic and free-living strains, either by molecular or morphological approaches, could be found. Sequences of Azolla cyanobiont filaments, taken directly from leaf cavities, clustered tightly with sequences from the planktic cyanobacterium Cylindrospermopsis raciborskii, from the benthic Anabaena cylindrica 133 and from Anabaena oscillarioides HINDAK 1984/43, with high bootstrap values. The phylogenetic analysis showed that two distinct patterns of evolution of symbiotic behaviour might exist for the nostocacean cyanobacteria, one leading to symbioses of Nostoc species with a wide variety of plants, the other leading to the association of a unique cyanobacterial type with the water fern Azolla.

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The Effect of Light on the Developmental Cycle of Nostoc muscorum, a Filamentous Blue-Green Alga

Cited by 73 publications

References 6 publications

Cellular Factors Affecting Nitrogen Fixation in the Blue-Green Alga Chlorogloea fritschii

Cellular Factors Affecting Nitrogen Fixation in the Blue-Green Alga Chlorogloea fritschii

Generic Assignments, Strain Histories and Properties of Pure Cultures of Cyanobacteria

Differential patterns of evolution and distribution of the symbiotic behaviour in nostocacean cyanobacteria

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