bluuebunny/crossref_metadata_2025_split huggingface dataset:
POLYMORPHIC BEHAVIOR OF ULVA LACTUCA (CHLOROPHYTA) IN AXENIC CULTURE. I. OCCURRENCE OF ENTEROMORPHA‐LIKE PLANTS IN HAPLOID CLONES1
Authors: Bonneau Edmund R. 
Published: August 2007

ABSTRACTAn isolate of Ulva lactuca L. was brought into axenic culture in both defined synthetic medium and enriched seawater. Haploid clones were established and followed through several generations in both media. Plants possessing distromatic, partially distromatic or completely tubular blades in cross sections, as well as individuals that were completely distromatic in one area of the blade and tubular in another all developed from the same swarmer population. Variations in basal area morphology also occurred. Progeny from swarmers of any of these morphological types showed a similar mixture of morphological variation, indicating non‐mutational variability in phenotypic expression of the blade and basal areas. A mechanism by which such variation may occur without mutation is discussed.
CULTURE AND HYBRIDIZATION STUDIES ONGIGARTINA PAPILLATA(RHODOPHYTA)1
Authors: Polanshek Alan R. , West John A. 
Published: August 2007

ABSTRACTThe foliose red algaGigartina papillata(C. Ag.) J. Ag. was studied in culture to determine its life history and possible relationship to the life history ofPetrocelis middendorffii(Ruprecht) Kjellman. Carpospores cultured from individual female plants gave rise to either crustosePetrocelis‐like plants that reproduced by tetraspores, or to another generation of foliose female (cystocarpic) plants that reproduced by carpospores. Apices cultured from blades of individual field‐collected female plants produced either papillae with many procarps that developed cystocarps only when crossed with male plants, or papillae with few procarps that produced cystocarps in the absence of male plants. The results are interpreted to demonstrate that two types of life history occur inG. papillata:one, a sexual life history involving a crustose tetrasporophyte; the other, a possibly apomictic life history involving only cystocarpic plants. Hybridization experiments demonstrated, thatG. papillatais interfertile withGigartina‐phase gametophytes cultured from tetraspores ofP. middendorffii.Sexual plants of G.papillataare postulated to represent the naturally‐occurring gametophyte ofP. middendorffiiin California. The possible relationships of the sexual and apomictic plants ofG. papillataare discussed.
THE GENUS PLATOMA (GIGARTINALES, RHODOPHYTA) WITH A DESCRIPTION OF P. ABBOTTIANA SP. NOV.1
Authors: Norris James N. , Bucher Katina E. 
Published: August 2007

ABSTRACTPlatoma abbottiana (Gymnophlaeaceae; Gigartinales), a new species of benthic red algae, is described from Isla Mejía and is the second member of this genus reported from the Gulf of California, Mexico. Vegetative anatomy and reproductive details of the carpogonial and auxiliary cell branches of the new species are described and illustrated. Geographical distributions of the seven previously described Platoma species are given. Their distinguishing morphological characteristics are compared to those of the new species. The correct time and place of valid publication of the generic name, Platoma, and some of its binomials are discussed.
TAXONOMIC SIGNIFICANCE OF SECONDARY CAROTENOID FORMATION IN NEOSPONGIOCOCCUM (CHLOROCOCCALES, CHLOROPHYTA)1
Authors: Deason Temd R. , Czygan Franz‐Christian , Soeder Carl J. 
Published: August 2007

ABSTRACTThe pigmentation of 23 species of Neospongiococcum Deason was studied in the stationary phase of nitrogen‐limited cultures on agar with or without glucose or in liquid medium. Fourteen species gradually developed an orange or brown color, and in all, secondary carotenoids were detected by thin‐layer chromatography. Among these, the keto‐carotenoids echinenone, canthaxanthin and esterified astaxanthin were identified, although the last named was not always present. When aging on glucose agar, the remaining nine species developed only a yellow‐green or yellow color and a pronounced tendency to bleach. In these, the aforementioned keto‐carotenoids were lacking, and β‐carotene and lutein lucre dominant. From this study it is not clear whether secondary carotenoid formation is species‐specific in Neospongiococcum.
LAUDERIA ANNULATA—A MARINE CENTRIC DIATOM WITH AN ELONGATE BILOBED NUCLEUS1
Authors: Robert W. Holmes 
Published: August 2007

ABSTRACT Lauderia annulata Cleve is probably unique among marine centric diatoms in possessing an elongate dumbbell‐shaped nucleus. A lobe at, each end of the nucleus lies adjacent to each valve during interphase and each lobe resembles a typical eucaryotic nucleus. The central portion of the thin strand, which passes through the vacuole connecting the two lobes is Feulgen positive and is nuclear membrane bounded. A group of micro tubules occurs in this strand clustered excentrically between, the nuclear membrane and the tonoplast. Evidence for the coordinated functioning of both nuclear lobes is suggested, by the aggregation of chloroplasts around, both lobes when shade‐adapted cells are exposed, to intense white or blue (400–500 nm) light.
PROBING PHYCOBILISOME STRUCTURE BY IMMUNO‐ELECTRON MICROSCOPY1
Authors: Gantt Elisabeth , Lipschultz Claudia A. 
Published: August 2007

ABSTRACTBy immuno‐electron microscopy it was shown that phycoerythrin is located on the outer surface of the phycobilisome and allophycocyanin is on the inside near the photosynthetic membrane in the red alga Porphyridium purpureum (Bory) Drew & Ross (P. cruentum). These findings are consistent with the idea that the phycobilisome junctions as a light harvesting antenna and energy sink, which directs the energy to chlorophyll in the photosynthetic membrane. A technique was devised in which unfixed phycobilisomes, attached to thylakoid vesicles, were separately reacted with three monospecific antisera (to B‐phycoerythrin, R‐phycocyanin and allophycocyanin) and the reaction products were secondarily marked by reaction with ferritin‐conjugated goat‐antirabbit gamma globulin fraction. This was subsequently followed by glutaraldehyde fixation and staining with phosphotungstic acid. The entire procedure was carried out on an electron microscope grid. The results confirm the previously proposed phycobilisome structural model.
METABOLIC SEGREGATION OF INTRACELLULAR FREE AMINO ACIDS IN PLATYMONAS (CHLOROPHYTA)1
Authors: Wheeler Patricia A. , Stephens Grover C. 
Published: August 2007

ABSTRACT 14C‐amino acids were supplied to Platymonas subcordiformis (Wille) Hazen and the incorporation of radioactivity into protein and other compounds was followed. Alanine was rapidly metabolized by both N‐limited and N‐sufficient cells. Arginine and lysine were metabolized rapidly by N‐limited cells, but were sequestered from metabolism in N‐sufficient cells. This suggests the existence of two functionally distinct pools; a “metabolic” pool that is rapidly metabolized and preferentially used for incorporation into protein, and a “storage” pool rich in basic amino acids that is sequestered from metabolism.
COPPER SORPTION AND RELEASE BY CYCLOTELLA MENEGHINIANA (BACILLARIOPHYCEAE) AND CHLAMYDOMONAS REINHARDTII (CHLOROPHYCEAE)1
Authors: Button Kenneth S. , Hostetter H. P. 
Published: August 2007

ABSTRACTInitial Cu++ sorption by Cyclotella meneghiniana Kütz. (Cu++‐sensitive) and Chlamydomonas reinhardtii Dangeard (Cu++‐resistant) was rapid in the first 5 min of Cu++ incubation with little sorption after 2 h. On a cell to cell basis, Cyclotella sorbed ca. five times more Cu++ from the medium than Chlamydomonas. In MBL medium with EDTA Cyclotella and Chlamydomonas cells sorbed 21.0 and 4.41 nM Cu++/106 cells respectively in 6 h with 0.3 mg Cu++/l in the medium. Proportionally similar quantities of Cu++ were sorbed when the cells were Cu++ incubated in MBL + citrate or filtered lake water. Cleaned cell walls of Cyclotella sorbed little Cu++ (1.7 nM/106 cells) as compared to living cells (17.5 nM Cu++/106 cells) in 3 h. Therefore, in living Cyclotella most of the Cu++ taken up must be absorbed by the protoplasm or perhaps by the organic layer surrounding the silica wall. Cleaned cell walls of Chlamydomonas sorbed 3.5 nM Cu++/106 cells and living Chlamydomonas cells sorbed 2.6 nM Cu++/106 cells. This indicates that most of the Cu++ sorbed by Chlamydomonas cells remained bound to the cell wall and probably did not readily enter into the protoplasm: When placed in Cu++ free medium after Cu++ incubation, Cyclotella and Chlamydomonas cells released 46 and 59% respectively of the Cu++ sorbed.
ELECTRON MICROSCOPE OBSERVATIONS ON THE INTERACTION OFBDELLOVIBRIO BACTERIOVORUSWITHPHORMIDIUM LURIDUMANDSYNECHOCOCCUSSP. (CYANOPHYCEAE)1
Authors: Burnham Jeffrey C. , Sun Donald 
Published: August 2007

ABSTRACTThe effects ofBdellovibrio bacteriovorus(Stolp & Starr) culture supernatants onPhormidium luridumvar.olivaceaBoresch andSynechococcussp. were examined by transmission electron microscopy. Both normal (nonheat‐treated) and heat‐treated bdellovibrio supernatant caused the formation of intrathylakoidal vesicles inP. luridumin 24–48 h. This vesiculation increased until 96–129 h when theP. luridumshowed loss of the mucopeptide layer in the cell envelope and subsequently lysed. Similar treatment ofSynechococcussp. with the bdellovibrio supernatants showed a different ultrastructural pattern with the apparent dissolution of many of the photosynthetic membranes in the bluegreen cells. Myelin‐like membranous configurations were seen in some of these treated cells. The results suggest that an autolytic mechanism inP. luridumandSynechococcussp. is stimulated by the bdellovibrio secretions.
EFFECTS OF IRON DEFICIENCY ON ISOCHRYSIS GALBANA (CHRYSOPHYCEAE) AND PHAEODACTYLUM TRICORNUTUM (BACILLARIOPHYCEAE)1
Authors: Glover Hilary 
Published: August 2007

ABSTRACTCultures of Isochrysis galbana Parks and Phaeodactylum tricornutum Bohlin were grown in iron‐limited chemostats. With increasing iron deficiency, photosynthetic rate per cell and assimilation number decreased. The pattern of photosynthesis was also altered; in Fe deficient cells the proportion of 14C fixed in glycine and serine decreased with an accompanying increase into alanine after 3 min assimilation. Although there was no significant effect of Fe deficiency on the proportion of 14C incorporated into total amino acids and amides, the percentage of total 14C fixed in protein increased with increasing Fe deficiency. Cellular levels of chlorophyll a, carotenoids, cytochromes and protein also decreased with increasing Fe deficiency. However, the reduction in chlorophyll a/cell was not as great as that of cytochrorne f1 and Fe deficient cells therefore showed a marked increase in chlorophyll a:cytochrorne f1 ratio.
FINE STRUCTURE OF NAUTOCOCCUS MAMMILATUS (CHLOROCOCCALES, CHLOROPHYCEAE), A COCCOID ALGA WITH TOMENTOSE CELL WALLS1
Authors: Deason Temd R. , Schnepf E. 
Published: August 2007

ABSTRACTThe unusual morphology of the coccoid, neustonic alga Nautococcus mammilatus Korschikov prompted its study with the electron microscope. Ultrastructural features including a fibrous cell wall with definite periodicity and an external tomentum were observed. These and other features of the alga are compared with those of related, species, and the use of cell wall characteristics in taxonomy is discussed.
ELECTRON MICROSCOPE OBSERVATIONS ON THE FLAGELLAR APPARATUS OFBRYOPSIS MAXIMA(CHLOROPHYCEAE)1
Authors: Hori Terumitsu 
Published: August 2007

ABSTRACTThe flagellar apparatus in male gametes of the siphonaceous green alga,Bryopsis maximaOkamura, was studied and compared with that of other green biflagellate cells. The proximal portions of two basal bodies are connected by a single striated proximal band, unique among the biflagellate reproductive cells of green algae studied. Anterior to the flagellar bases is a pair of distal bands different from the single structure in other biflagellate cells. These bands which arise from the distal portion of each basal body, extend upward in the papilla and curve down toward the lower edges of the basal bodies. They seem to have no direct association with each other. Two pairs of distinct flagellar roots, one consisting of 3–5 microtubules and the other of a partially striated fiber of undetermined numbers of microtubules, diverge from the basal body region and extend towards the cell posterior. Their component microtubules are disorganized into single or smaller groups midway over the cell length. The uniqueness of the flagellar apparatus is briefly discussed.
STEADY STATE GROWTH OF PHYTOPLANKTON IN CONTINUOUS CULTURE: COMPARISON OF INTERNAL AND EXTERNAL NUTRIENT EQUATIONS1,2
Authors: Goldman Joel C. 
Published: August 2007

ABSTRACTPreviously, there have been conflicts over whether external or internal nutrient concentrations control phytoplankton growth rates at steady state in continuous culture. To experimentally demonstrate that both equations equally describe steady state growth, continuous culture studies with phosphorus‐limited growth of the chrysophyte Monochrysis lutheri Droop were carried out over the entire growth rate region up to biomass washout. Data were examined using both the Monod and Droop equations, and, even though there were significant variations in the yield coefficient with growth rate, the data fit both equations reasonably well. Because of their relative simplicity, the Droop equation and an equation combining both the Monod and Droop equations are better suited for expressing kinetic data than the Monod equation. It is crucial, though, that the criteria necessary to achieve steady state be fulfilled.
AN ABERRANT CHRYSOPHYCEAN ALGA PELAGOCOCCUS SUBVIRIDIS GEN. NOV. ET SP. NOV. FROM THE NORTH PACIFIC OCEAN1,2
Authors: Lewin Joyce , Norris Richard E. , Jeffrey S. W. , Pearson Barbara E. 
Published: August 2007

ABSTRACTA description and Latin diagnosis of the new genus and species Pelagococcus subviridis Norris is presented. Pale green, spherical cells appeared in enrichment cultures initiated from water samples collected at stations between 132°W and 175°W and between 45°N and 50°N in the North Pacific Ocean. The alga is placed in the Chrysophyceae based on organelle fine structure, and presence of chlorophylls a and c, diatoxanthin, diadinoxanthin and two fucoxanthin‐like pigments. There are a number of atypical features however; the two fucoxanthin‐like pigments differ from true fucoxanthin; there is only chlorophyll c2 (not C1+ c2); probably mostly a, not β‐carotene; half of the chlorophyll a is in the form of chlorophyllide a.
CONTINUOUS FLOW CULTURE OF BENTHIC DIATOMS AND ITS APPLICATION TO BIOASSAY1,2
Authors: Lin C. Kwei 
Published: August 2007

ABSTRACTThe benthic diatom,Navicula seminulumvar.hustedtiiPatr, was isolated from the field and studied in laboratory cultures. Experiments were conducted to determine the suitability of Millipore membranes and solidified agar substrate for diatom colonization under continuous flow conditions. Diatom colonization showed large variation and low reproducibility on Millipore membranes of different materials and pore sizes. Solidified agar substrate supported stable and reproducible colonization and is nutritionally neutral, translucent, homogeneous and easy to sample. The diatom colonization process on agar substrate involved four growth phases: i) pioneer; ii) exponential; iii) steady state; and, iv) vanishing. The culture system was also used in bioassay, testing the toxic effect of copper on the growth of benthic diatoms. The proposed method provides a useful means for studying autecology of benthic diatoms as well as for bioassay work.
EFFECT OF BLUE‐GREEN LIGHT ON PHOTOSYNTHETIC PIGMENTS AND CHLOROPLAST STRUCTURE IN THE MARINE DIATOM STEPHANOPYXIS TURRIS1
Authors: Jeffrey S. W. , Vesk Maret 
Published: August 2007

ABSTRACTBlue‐green light increased the chlorophyll concentration and chloroplast number of cells of Stephanopyxis turris (Grev.) Ralfs, compared to white light controls. Light fields for growth were 400 μW·cm−2 (12:12 LD cycles). Chlorophyll increased up to 100%/cell, but no change in the ratio of chlorophylls to major carotenoids occurred. The effect was, therefore, not that of complementary chromatic adaptation. At the same time, blue‐green light enhanced the photosynthetic fixation of CO2. At the ultrastructure level, an increase in, and rearrangement of, the thylakoid system occurred.
EFFECT OF BLUE‐GREEN LIGHT ON PHOTOSYNTHETIC PIGMENTS AND CHLOROPLAST STRUCTURE IN UNICELLULAR MARINE ALGAE FROM SIX CLASSES1
Authors: Vesk Maret , Jeffrey S. W. 
Published: August 2007

ABSTRACTThe photosynthetic pigments of 17 species of unicellular marine algae grown in white and blue‐green light were examined. Blue‐green light (400 μW·cm−2; 12:12 LD cycle) caused major chlorophyll increases (55–146%) in five diatoms, one dinoflagellate and one cryptomonad; minor chlorophyll increases (17–39%) in two diatoms, two dinoflagellates, one prymnesiophyte (haptophyte), one chrysophyte and one chlorophyte; and no chlorophyll increase in two diatoms and one pyrmnesiophyte (haptophyte). The relative proportions of major chlorophylls and carotenoids did not change, but in six of eight species tested small increases in the concentration of chlorophyll c occurred. Blue‐green light caused a small increase in the concentration of phycoerythrin relative to chlorophyll a in the cryptomonad. A larger number of thylakoids per chloroplast were observed in six species grown in blue‐green light compared to white light controls. The ultrastructure changes observed depended not only on the magnitude of the chlorophyll increase but also on the architecture of the chloroplast.
EFFECT OF NITROGEN SOURCE ON PLATYMONAS (CHLOROPHYTA) CELL COMPOSITION AND AMINO ACID UPTAKE RATES1
Authors: Wheeler Patricia A. 
Published: August 2007

ABSTRACTThe effect of nitrogen source (nitrate, ammonia and/or amino acids) on cell composition and amino acid uptake rates was examined. Substantial levels of free amino acids accumulated intracellularly with all nitrogen sources used. Ammonia accumulated only when provided in the medium. The presence of ammonia in the medium decreased the intracellular accumulation of free amino acids, especially arginine. Amino acid uptake rates were suppressed by the presence of excess nitrogen, especially ammonia. However, the suppression of uptake did not show any particular relation to the nitrogenous cell composition.
HETEROTROPHIC NUTRITION AND ITS EFFECTS ON CHLOROPHYLL SYNTHESIS INGOLENKINIA(CHLOROPHYCEAE)1
Authors: Ellis Richard J. 
Published: August 2007

ABSTRACTGlucose and sodium acetate are the only carbon sources able to support heterotrophic growth ofGolenkinia minutissimaIyengar & Balakrishnan. Heterotrophic growth is maximal at a concentration range of 20–40 mM of either carbon source; however, growth is significantly more rapid and higher yields are obtained with acetate. Mannose is toxic but this effect is competitively reduced by the presence of glucose. The inhibitory action of acetate on chlorophyll synthesis is unaffected by 20 mM glucose, indicating that this inhibition is not related to the absence of glucose.
FEULGEN MICROSPECTROPHOTOMETRIC INVESTIGATION OF THE LIFE HISTORY OF FRITSCHIELLA TUBEROSA(CHLOROPHYCEAE)1
Authors: Hopkins Archibald W. 
Published: August 2007

ABSTRACTA Feulgen microspectrophotometric analysis of successive generations of Fritschiella tuberosa Iyengar revealed an asexual repeating of one generation rather than an obligate alternation of isomorphic generations as previously described. F. tuberosa regularly reproduces asexually by the release of one quadriflagellate zoospore produced/cell in all parts of the upright and prostrate portions of the thallus. In the vegetative thalli, nuclei in the G1 (pre‐synthesis), synthesis, and G2 (post‐synthesis) phases of the mitotic cycle are all well‐represented.
HISTOCHEMICAL STUDIES OF THE EXTRACELLULAR CARBOHYDRATE OF COLACIUM MUCRONATUM (EUGLENOPHYCEAE)1
Authors: Willey Ruth L. , Ward Kathleen , Russin William , Wibel Ronald 
Published: August 2007

ABSTRACTThe stalk of Colacium mucronatum Bourr. & Chad. is composed primarily of a cylindrical shaft with a lightly staining inner core and diffuse peripheral cortex. The shaft and cortex arise from a ring‐shaped region around the canal opening whereas the core appears continuous with the canal which may be associated with initial cell attachment. All parts of the stalk, as well as the lining and contents of the reservoir, canal and flagellum exhibit stain reactions associated with neutral or mildly acidic carbohydrate with widely spaced anionic groups in low concentration.
IMMUNOFLUORESCENCE FOR AUTECOLOGICAL STUDY OF A UNICELLULAR BLUEGREEN ALGA12
Authors: Fliermans C. B. , Schmidt E. L. 
Published: August 2007

ABSTRACTFluorescent antibody (FA) preparations were developed and tested as an approach to recognition and enumeration of a specific unicellular bluegreen alga in a natural ecosystem. Antibodies made against an axenic culture of Synechococcus cedrorum Näg. gave a high agglutination titer and an excellent homologous staining reaction. Antibody specificity was tested with 28 heterologous cultures of bluegreen algae, known cultures of chemoautotrophic bacteria and heterotrophic bacteria, and randomly selected unknown bacteria from soil, sewage and aquatic habitats. FA staining of bluegreen algae was restricted to S. cedrorum and six heterologous isolates, all indistinguishable microscopically from S. cedrorum. The ability to enumerate S. cedrorum FA‐reactive cells in nature was demonstrated with data on population densities for samples taken from water columns of stratified holomictic lakes in northcentral Minnesota.
NITRATE REDUCTASE MUTANTS IN EUDORINA ELEGANS (CHLOROPHYCEAE)1
Authors: Toby Anne L. , Kemp C. Lindley 
Published: August 2007

ABSTRACTThree nitrate reductase mutants were independently isolated and characterized in the colonial alga, Eudorina elegans Ehrenberg. nar‐1 is a leaky mutant, deficient in the production of nitrate reductase. nar‐2 and nar‐3 both lack the ability to produce nitrate reductase. However, nar‐2 grows and nar‐3 does not grow when hypoxanthine is the sole nitrogen source. The specific activity of the next enzyme, in the pathway, nitrite reductase is increased in nar‐3 when compared to wild‐type, nar‐1 and nar‐2.
INVERSION IN VOLVOX (CHLOROPHYCEAE)1
Authors: Kelland John Laurence 
Published: August 2007

ABSTRACTThe asexual embryos of Volvox turn themselves inside out (invert) during development. Data presented indicate that inversion of the embryos is the result of several simple cellular shape changes, coordinated in space and time. Using whole embryos, cell groups and individual embryonic cells isolated by watchmaker's forceps and pressure on the coverslip, it was shown that the phialopore (opening) enlargement and concurrent stretching of the border cells is due to a constriction formed at the equator. However, if the posterior hemisphere is removed, this constriction no longer effects the expansion of the phialopore (which is in the anterior hemisphere) because the equatorial region is no longer anchored and has no base to support the outwardly directed force against the phialopore cells. If the posterior hemisphere is isolated several hours before inversion, the opening resulting from the incision acts as a “phialopore” and the direction of inversion is reversed. Individual cells and cells in groups undergo the same shape changes as corresponding cells in an intact embryo during inversion. This suggests that these cellular deformations are autonomous and inversion is a result of them.