bluuebunny/crossref_metadata_2025_split huggingface dataset:
ROLE OF H2O2 IN SINGLE‐CELL GROWTH OF THE BLUE‐GREEN ALGA, ANACYSTIS NIDULANS1
Authors: Marler James E. , van Baalen C. 
Published: April 2007

SUMMARY Inhibition of growth of single cells of Anacystis nidulans on the surface of or in plates was due to H2O2. This H2O2 arises from reaction of citrate and Mn2+ in a defined medium, C, by heat (autoclaving) or light (especially 365 mμ). The simplest way to avoid H2O2 formation was to lower or omit Mn2+ from the medium. Thus medium C minus Mn2+ routinely gave excellent quantitative growth of single cells of Anacystis under simple incubation conditions. The H2O2 sensitivity of Anacystis was unexpectedly high; ≈ 50 μg/liter inhibited single cells on the surface of agar plates. However, other blue‐greens tested had not this exaggerated sensitivity. Seawater contained small quantities of apparently free H2O2. H2O2 in seawater perhaps may have an ecological role.
GROWTH AND MATING OF GONIUM PECTORALE (VOLVOCALES) IN DEFINED MEDIA1
Authors: Stein Janet R. 
Published: April 2007

SUMMARY Growth in defined media of 32 populations of Gonium pectorale was studied to learn more about the sexual isolation reported for this species. The 23 populations containing both mating types (+ & ‐) icere also studied for the ability to form zygotes in defined media. A preliminary study showed that some populations grew and reproduced sexually in a defined mineral medium, whereas others appeared to require exogenous organic materials for growth and/or zygote formation. The diverse reactions exhibited by the populations indicate physiological races which may explain, in part, the occurrence of sexual isolation.
DISTRIBUTION OF SAXICOLOUS CRUSTOSE CORALLINES IN THE NORTHWESTERN NORTH ATLANTIC1
Authors: Adey Walter H. 
Published: April 2007

SUMMARY The relative abundances of species of crustose coralline, as derived from areal measurements of large collections taken from Nova Scotia to Labrador, are given as a function of depth and as a function of mean maximum temperature and depth. The relative effects of depth and temperature independently are indicated and in most cases the results are markedly similar to those found in earlier Gulf of Maine studies. The distributions of Pseudolithophyllum orbiculatum and Phymatolithon rugulosum apparently are not controlled by summer temperatures in this area.
UNUSUAL PHENOMENA IN THE LIFE HISTORIES OF FLORIDEAE IN CULTURE1
Authors: West John A. , Norris R. E. 
Published: April 2007

SUMMARY Several Florideae grown in natural seawater media under defined laboratory conditions have interesting and unusual life histories. Antithamnion occidentale males of one generation produced tetraspores that gave rise to nonsporangiate males. The functional females of A. pygmaeum developed spermatangia and tetrasporangia; the tetraspores formed new females. Antithamnion defectum tetrasporophytes of one generation bore spermatangia in addition to tetrasporangia; the tetraspores gave rise to typical gametophytes. Tetraspores from successive generations of Callitham‐nion sp. developed into tetrasporophytes and males but no females were produced. Functional female gametophytes of Platythamnion sp. bore abortive tetrasporangia. Field‐collected plants of two species of Fauchea produced tetraspores that yielded additional sporangiate plants: those of F. pygmaea being bispo‐rangiate and tetrasporangiate, and those of F. lacini‐ata being strictly tetrasporangiate. Male plants of Pleonosporium vancouverianum from a running seawater table bore spermatangia and polysporangia when collected. The same plants in unialgal culture produced only spermatangia.
PLEUROCLADIA LACUSTRIS IN ARCTIC AMERICA1
Authors: Wilce R. T. 
Published: April 2007

SUMMARY Several large populations of Pletirocladia lacustris A. Br. were found at Devon Island, N.W.T., Canada, in an intermittently marine habitat. The morphology, cytology, and ecology of this species were described from living material from two habitats, the limestone and granite shores. The genus Kolderupia Lund ivas found synonymous with Pleurocladia; consequently Kolderupia maritima and K. lucifuga were lectotypified, characterized, and transferred to Pleurocladia. The genus Pleurocladia should be regarded as a member of the Ectocarpaceae until life history studies show a need for reclassification. In the Ectocarpaceae, Pleurocladia is probably most closely related to Protectocarpus Kuckuck. The distribution of P. lacustris indicated that the species, if not extremely rare, is uncommon.
CHLOROPLAST PIGMENTS OF CHLOROMONADOPHYCEAE
Authors: Chapman David J. , Haxo F. T. 
Published: April 2007

SUMMARY The chloroplast pigments of 2 species of Chloro‐monadophyceae have been examined. Both Gonyo‐stomum semen and Vacuolaria virescens possessed only one chlorophyll, chlorophyll a. Gonyostomum contained 4 carotenoids, but not fucoxanthin and peridinin. Vacuolaria also possessed 4 carotenoids which have been identified as β‐carotene and the 3 xanthophylls commonly found in the Xanthophyceae (as represented by Tribonema aequale). These are antheraxanthin, lutein monoepoxide, and an hydroxy lutein monoepoxide‐like xanthophyll. The taxonomic significance of these findings, the first for the Chloromonadophyceae, is discussed.
THE EFFECT OF pH ON THE DIVISION RATE OF THE COCCOLITHOPHORID CRICOSPHAERA ELONGATA1
Authors: Swift Elijah , Taylor W. Rowland 
Published: April 2007

SUMMARY The division rate of Cricosphaera elongata was measured as a function of pH in a medium buffered with the CO2‐bicarbonate‐carbonate system. The optimum pH for cell division of the coccolithophorid was 7.8. A change of the partial pressure of CO2 in the medium from 0.03 to 5% did not affect the division rate. Between pH 6.4 and 7.8 changes in the bicarbonate concentration from 0.1 to 6.0 mm and carbonate concentration from 0.007 to 0.1 mm did not affect the rate of division. At loiv experimental pH, C. elongata was nonmotile and grew in clumps; at higher pH values, it was motile and solitary. Coccoliths were not found covering C. elongata if calcite was soluble in the medium.
OBSERVATIONS ON LIAGOROPHILA ENDOPHYTICA, A RARE SPECIES IN THE ACROCHAETIACEAE (RHODOPHYCEAE)1
Authors: Abbott Isabella A. 
Published: April 2007

SUMMARYLiagorophila, a monotypic genus in the Acrochaetiaceae (Nemalionales) from the zuestern Pacific, is redescribed, particularly with reference to its sexual reproductive structures. The fertilized carpogonium shows a longitudinal first division; the spermatangia may be borne directly on a normal vegetative cell. Monosporangia are not known. For these reasons, and although vegetatively resembling some species of Acrochaetium, the genus should be recognized as distinct from other genera of Acrochaetiaceae.
BORON AS A GROWTH REQUIREMENT FOR DIATOMS1
Authors: Lewin Joyce 
Published: April 2007

SUMMARY A boron requirement has been shown for 12 species of marine pennate diatoms, 4 species of marine centric diatoms, and S freshwater diatom species. It can be concluded that boron is essential for the growth of most, probably all, diatoms. It is much easier to demonstrate a requirement for the marine species than for the freshwater species. Some species of marine algal flagellates also require boron for growth; others apparently do not.
RELATIONSHIP OF TEMPERATURE TO ZOOSPORE PRODUCTION IN TETRASPORA GELATINOSA
Authors: Rhodes Russell G. , Herndon Walter R. 
Published: April 2007

SUMMARY A strain of Tetraspora gelatinosa was isolated from a field collection and a technique for measuring quantitatively the production of zoospores was devised. The method employed compound colonies grown on agar from zoospore suspensions. The effect of 3 temperatures on zoospore production was tested: no zoospores were produced by the colonies at 3 C; zoospores were produced at 11 and 23 C and the final yield of zoospores at the 2 temperatures was not significantly different. However, at 11 C the maximum density of zoospores produced, measured by cell count, occurred after IS hr, while the maximum density at 23 C occurred after 21 hr.
PULCHRASPHAERA, A NEW CHLOROCOCCALEAN GENUS1
Authors: Deason Temd R. 
Published: April 2007

SUMMARYPulchrasphaera macronucleata gen. et sp. nov. was isolated from a sand dune on Dauphin Island, Alabama. The distinguishing attributes of the genus include a lobed and perforate parietal chloroplast, lack of pyrenoids, and Protosiphon‐type zoospores. The specific epithet calls attention to the unusually large nucleus, a character useful in distinguishing P. macronucleata from other spherical, zoospore producing members of the Chlorococcales.
A SECOND RECORD OF PORPHYRIDIUM SORDIDUM GEITLER1
Authors: Ott Franklyn D. 
Published: April 2007

SUMMARY A second record of the occurrence of Porphyridium sordidum Geitler 1932 is reported. Cultures were obtained by plating crude material on agar plates of various salinities with the higher salinities selectively favoring the growth of this species. Proposed synonymy of P. sordidum with P. cruentum is rejected. The author suggests that more attention be given to the establishment and use of depositories for living unialgal, reference cultures in taxonomical work on the more delicate algae, and that taxonomical manipulations of such forms based only upon word descriptions and the study of dried herbarium material should be viewed with a degree of caution.
ECOLOGY OF CLADOPHORA GLOMERATA (L.) KÜTZ IN SOUTHERN ONTARIO1
Authors: Bellis V. J. , McLarty D. A. 
Published: April 2007

SUMMARYCladophora glomerata (L.) Kütz. was the dominant attached alga in streams and along lake shores in southern Ontario. Maximum production occurred in summer and resulted from 2 short periods of intensive vegetative growth (June and September). Optimum habitat conditions consist of a firm substrate in shallow alkaline water. These conditions are provided by harbor facilities where man‐made structures supplement naturally occurring rock outcrops or cobble beaches and where nutrients are available from tributaries draining agricultural and urban land areas. Periodicity appears to be related to temperature; the interval between the 2 periods of intensive growth during warm weather decreases at successively more northern locations. Frequent observation of Cladophora growing at a single stream station revealed that variations in thallus morphology and relative cell dimensions of C. glomerata are greater than has generally been recognized. These variations can be attributed to changes in environmental conditions and events in the annual life cycle of the alga.
BIOLUMINESCENCE AND CHLOROPLAST MOVEMENT IN THE DINOFLAGELLATE PYROCYSTIS LUNULA1
Authors: Swift Elijah , Taylor W. Rowland 
Published: April 2007

SUMMARY The lunate cysts of Pyrocystis lunula have a bioluminescent emission spectrum with a peak intensity of 477.5 ± 1 mμ. The light originates from the protoplasm in the center of the cysts. Six to eight hr after the cysts were placed in the dark, they produced 300 to 800 times more luminescence than controls maintained under constant, illumination. Plastids contract distally when the cysts are placed in the dark. If kept in the dark, the plastids contract distally and expand with a circadian rhythm persisting several days. At intensities of 2200 μm cm‐’or less, the plastids are expanded. The plastids are contracted into the central area of the cysts at light intensities of 4000 μw cm‐2 and above. The Gymnodinium stage of the life cycle is not bioluminescent.
THE LIFE CYCLE OFPEDIASTRUM SIMPLEX1
Authors: Davis Joseph S. 
Published: April 2007

SUMMARYA sexual cycle and a newly discovered mode of asexual reproduction by azygotes arc described forPediastrum simplex.In the sexual cycle isogametes from colony cells fuse in pairs, develop into zygotes, which grow and divide, producing motile cells which become angular polyeders. Polyeders may divide internally to form 4‐celled colonies, or they enlarge, cleave, and produce zoospores or nonmotile cells. Zoospores are released in vesicles, swarm, adhere to each other, and form, flat colonies I cell thick. The nonmotile cells adhere to each other, enlarge, break out of the polyeder, and become spheroidal colonies. In the asexual cycle, nonfusing gametes, and motile cells derived from colony cells, become 4‐spined azygotes which enlarge, divide internally, and release motile cells developing into polyeders. These polyeders develop further like those from zygotes.
AN ULTRASTRUCTURAL STUDY OF THE GIANT GREEN ALGAL COENOCYTE, CAULERPA PROLIFERA
Authors: Dawes Clinton J. , Rkamstine Ernest L. 
Published: April 2007

SUMMARY The general fine structure of the giant coenocyte Caulerpa prolifera (Forsskål) Lamouroux is presented. The cytoplasm forms a parietal layer throughout the plant without any regular membranous separations within organs or between organs. The vacuome is similar in structure. There are distinct patterns of organelle distribution in the highly polar cytoplasm of rhizoids and blades. The organelles are compared to those of other members of the division Chlorophyta and are typical. Amyloplast structure is compared to that of chloroplasts. A possible developmental sequence from chloroplast buds through an unusual circular body is suggested.
MITOTIC WAVES IN THE GREEN ALGA BLASTOPHYSA RHIZOPUS AS RELATED TO COENOCYTE FORM1
Authors: Sears James R. 
Published: April 2007

SUMMARY The pattern of mitotic activity is related to form in the small coenocytic green alga Blastophysa rhizopus Reinke. Mitoses occur as a wave pattern within single nonspheroidal coenocytes, whereas within single spheroidal cocnocytes, nuclear divisions are completely synchronous. The waves are um‐ or bidirectional, depending on the region of mitotic wave initiation. factors which may be influenced by the external microenvironment of different coenocytic forms arc suggested as possible mitotic initiators.
PILAYELLA LITTORALIS F. RUPINCOLA FROM WASHINGTON: THE LIFE HISTORY IN CULTURE1
Authors: West John A. 
Published: April 2007

SUMMARY The life history of Pilayella littoralis f. rupincola from Washington was studied in culture using supplemented natural seawater media and various temperature, photoperiod, and light intensity regimes. Plants in nature exhibited characteristics typical for f. rupincola. Plants in culture, however, did not show the same morphological features, although they had a life history presumed typical for f. rupincola. Successive generations of plants in culture formed only unilocular sporangia. On the basis of morphological characters and the life history, Kylin elevated f. rupincola to species rank. Variation in morphology of both field collected and cultured specimens makes such recognition untenable. It is concluded that the type of life history alone is not adequate justification for the recognition of P. rupincola as a species, but the stability of the life history in various culture environments appears to warrant continued recognition of this taxon as a distinct form of P. littoralis, as originally proposed by J. E. Areschoug.
FLOATING COMMUNITIES OF ALGAE IN AN ARTIFICIAL POND IN THE PARQUE DO ESTADO, SÃO PAULO, BRAZIL1
Authors: de Mattos Bicudo Carlos Eduardo , Teixeira Bicudo Rosa Maria 
Published: April 2007

SUMMARY A fresluvater floating algal community was repeatedly observed in an artificial pond in the Parque do Estado São Paulo, Brazil. The ontogeny and composition of the community are discussed and are related to oxygen liberation during photosynthesis of the periphyton, or of the pond‐bottom algne, which carries up portions of the algae growing there.
ELECTRON MICROSCOPIC STUDIES OF EXTRAPLASTIDIC ASTAXANTHIN IN HAEMATOCOCCUS12
Authors: Lang Norma J. 
Published: April 2007

SUMMARY The ketonic carotenoid astaxanthin accumulates in perinuclear cytoplasm characterized by a network of ribosome‐coated endoplnsmic reticulum segments, free ribosomes, dictyosomes in active stages of vesicle formation, and mitochondria. The pigment granules form in the ground substance and not within any organelle or vesicle. Coalescence of the globular granules results from increasing quantities of astaxanthin formed as the cells age. The gross differences in fixation image following glzitaraldehyde‐KMnO4 and glutaraldehyde‐OsO4 are illustrated, and the need for n variety of fixations upon which interpretations are bused is emphasized. The bright red coloration of akinetes is due to a masking of the chlorophyll by the massive astaxnnthin deposits rather than m y break‐down of the chloroplast thylakoids.
UNIALGAL CULTURES OF CLADOPHORA GLOMERATA (L.) KÜTZ.12
Authors: Bellis V. J. 
Published: April 2007

SUMMARY Unialgal cultures of Cladophora glomerata (L.) Kütz. grew with increasing vigor at temperatures between 15 and 30 C. Vegetative cells were killed upon freezing or when exposed to temperatures above 30 C. No growth occurred at 5 C and only slight growth was observed at 10 C. Effects of near lethal temperature on C. glomerata were dependent upon the duration of exposure in addition to the actual temperature attained. The response of this alga to various temperatures under culture conditions is in accord with tolerance limits established for naturally occurring populations. It seems probable that the annual periodicity of C. glomerata is regulated in large measure by seasonal variations in water temperature, greatest abundance coinciding with water temperatures between 15 and 30 C.
NEW SPECIES OF HALIMEDA: A TAXONOMIC REAPPRAISAL12
Authors: Colinvaux Llewellya Hillis 
Published: April 2007

SUMMARY A study of new Halimeda material available from the International Indian Ocean Expedition, and of type and other specimens not previously available to me, further indicated that Halimeda opuntia is a composite of species rather than a single species. The characteristics of some of its infraspecific taxa differ sufficiently from typical H. opuntia that I have elevated them to species. Extended diagnoses of three, H. hederacea, H. minima, and H. distorta, are given in this paper. Some characteristics new in Halimeda taxonomy are introduced, and distinguishing macroscopic and microscopic characteristics for the new species are discussed. Available ecological data are included.
REPRODUCTION IN HELICODICTYON PLANCTONICUM (WHITFORD) WHITFORD AND SCHUMACHER1
Authors: Biebel Paul 
Published: April 2007

SUMMARY Reproductive stages of a Helicodictyon planctonicum strain from Pennsylvania were observed in cultures. The adult colonial form is enclosed within a mucilaginous matrix and contains a gas bubble. In older cultures some colonies lose their gas bubbles and sink to the bottom of the culture solution. When these colonies from the bottom of old cultures are transferred to fresh medium, their cells become transformed into biflagellate motile cells. Motile cells fuse in pairs to form zygotes. Some motile cells lose motility and develop directly into adult colonies without prior fusion.
PRODUCTION OF MALE GAMETES AND AUXOSPORES IN THE CENTRIC DIATOMS CYCLOTELLA MENEGHINIANA AND C. CRYPTICA12
Authors: Schultz Mary E. , Trainor Francis R. 
Published: April 2007

SUMMARY Vegetative cells of Cyclotella meneghiniana Kützing form male gametes and anxospores following transfer from a synthetic freshwater medium to a modified artificial seawater. Both spermatogenesis and auxospore formation are correlated with an increase in the Na+ concentration in the medium. Spermatogenesis can also be induced in C. cryptica Reimann, Lewin, and Guillard in artificial seawater with an adjusted sodium level.
MECHANISM OF TOXICITY AND RESISTANCE TO D‐MANNOSE AND CERTAIN DERIVATIVES IN SPECIES OF THE GENUS CHLORELLA BEIJ.12
Authors: Gross Rudolf E. 
Published: April 2007

SUMMARY
d‐Mannose and related derivatives, e.g., d‐glucosa‐mine and 2‐deoxy‐<d‐glucose, blocked autotrophic and heterotrophic growth of several species of the genus Chlorella. Manometric studies showed differences in the effects of these compounds on substrate‐induced O2 uptake, indicating different modes of action. In a clonal culture, shaken in the light, mannose produced a lag phase of 7 days during which only ca. 0.05% of the cells continued to grow. From, these cells a resistant strain was isolated. Prolonged incubation in glucose media in darkness brought about a reversion to the sensitive condition. These metabolic shifts could not be explained on the basis of adaptation or nuclear gene mutation because of the permanency and high frequency of the resistant cells. The mechanism was suggested to be cytoplasmically controlled. The shift in sensitivity to the inhibitors was considered a reproducible characteristic of certain species. In contrast to the normal, rnannose‐sensitive strain of C. infusionum var. acetophila, cells of a resistant strain carried a gelatinous envelope. The resistant strain utilized glucosamine as a source of nitrogen, but lost the capacity to use sugars for dark growth. This was reflected in drastic reductions in glucose and mannose uptake. The hexokinase activities in cell extracts were equivalent for both strains. The resistant strain did not accumulate hexose‐6‐phos‐phates and showed an increased phosphatase activity at an alkaline pH.
PRESENCE OF A SECOND FLAGELLUM IN CHRYSOSPHAERELLA MULTISPINA1
Authors: Wujek Daniel E. 
Published: April 2007

SUMMARY The genus Chrysosphaerella, originally described by Lauterborn as having a single flagellum and later emended by Korshikov who observed a second flagellum, was studied using the electron microscope. Electron micrographs confirm Korshikov's observation ivhich in most recent classification schemes has been overlooked,
ULTRASTRUCTURE OF THE THERMOPHILIC BLUE‐GREEN ALGA, SYNECHOCOCCUS LIVIDUS COPELAND1
Authors: Edwards Mercedes R. , Berns Donald S. , Ghiorse William. C. , Holt Stanley C. 
Published: April 2007

SUMMARY The ultrastructure of Synechococcus lividus Copeland, a thermophilic blue‐green alga, was studied in thin sections. The cell envelope reveals striking similarities with that of some gram‐negative bacteria. In contrast to bacteria and to many other species of blue‐green algae, ribosomes are predominantly found in the central nuclear region and appear to be associated with the DNA fibrils. Thylakoids (photo‐synthetic lamellae) are arranged as concentric shells, around the nuclear equivalent, lying nearly parallel to one another and to the plasma membrane. Both plasma and thylakoidal membranes, as described by other authors for different Cyanophyceae, are of the unit membrane dimension and morphology. Various types of intracellular inclusions are found: (1) Lipid inclusions, located in the cytoplasm are similar to the osmiophilic globules of higher plant chloroplasts. (2) Polyphosphate inclusions (or volutin) resembling those of other species are generally found at the cell poles but within the nuclear region. (3) Polyhedral inclusions also located in the nuclear region are clearly recognized to be different from the polyphosphate bodies, but their function remains unknown.
ON PIGMENTS, GROWTH, AND PHOTOSYNTHESIS OF PHAEODACTYLUM TRICORNUTUM12
Authors: Mann James E. , Myers Jack 
Published: April 2007

SUMMARY A maximum growth rate with doubling time of 18 hr at 18 C could be maintained. Continuous cultures at about half maximum growth rate provided cells for study of pigments and photosynthesis. The light intensity curve of photosynthesis had no unusual features and showed light‐saturated rates of 30‐35 μl O2/mrn3‐hr at 18 C. Pigment analysis showed chlorophylls a and c (a/c ratio = 4), fucoxanthin, β‐carotene, and diadinoxanthin. Growth under red light (±660 mμ) altered pigments only by decrease in chlorophyll c to about one‐half the content obtained under clear tungsten lamps. The large and anomalous spectral shift in fucoxanthin following organic solvent extraction runs confirmed, but efforts to isolate a native fucoxanthin were unsuccessful. Spectral analysis of acetone extracts and sonicated cell preparations allowed estimate of fractional absorption by each component pigment. The analysis shows that chlorophyll a and fucoxanthin are the principal light absorbing pigments and that absorption by other carotenoids is very small.