bluuebunny/crossref_metadata_2025_split huggingface dataset:
GROWTH OF GONIUM MULTICOCCUM IN SYNTHETIC MEDIA1
Authors: Saito Shôichi 
Published: August 2010

SUMMARYNutrient requirements of Gonium multicoccum (strains 7–1 and 7–2) were investigated in detail. Acetate supported, most efficiently growth in both continuous light and dark. Acetate could be replaced with pyruvate or lactate in the continuous light, but not in the dark. Sugars were completely ineffective. Thiamine was required for optimum growth. The addition of B12 reduced lag phase, but it did not change the final yield. As the sole nitrogen source, nitrate, ammonia, and urea were equally effective. Nitrite, arginine, glutamine, and uric acid, supported scant growth. Examination of the major and minor mineral requirements resulted, in an optimal medium. A growth rate as high as 5.8 doublings per day was obtained at 25 C in continuous light.
CELLULAR ORGANIZATION, MITOSIS, AND CYTOKINESIS IN THE ULOTRICHALEAN ALGA, KLEBSORMIDIUM1,2,3
Authors: Floyd Gary L. , Stewart Kenneth D. , Mattox Karl R. 
Published: August 2010

SUMMARYMitosis, cytokinesis, and cellular organization during interphase are described. Interphase cells possess a single microbody‐like organdie which occurs between, and is appressed to, the chloroplast and nucleus. The microbody‐like organelle divides during mitosis and. the division of the chloroplast. Anaphase is unusual in that chromosome‐to‐spindle pole distance remains constant even though the 2 groups of chromosomes become widely separated. When anaphase is half completed, a vacuole forms in the interzonal region and appears to be involved in further separation of the chromosomes. Vacuolar development is also involved with events of early interphase. The cytology of K. flaccidum is compared to those of Ulothrix fimbriata and Stigeoclonium helveticum. The comparison, does not support the present classification of the 3 species, and indicates the value of comparative fine structural studies in the classification of ulotrichalean algae.
OVERWINTERING OF DICTYOTA DICHOTOMA (PHAEOPHYCEAE) NEAR ITS NORTHERN DISTRIBUTION LIMIT ON THE EAST COAST OF NORTH AMERICA1
Authors: Richardson Joseph P. 
Published: August 2010

ABSTRACTThe mechanism of yearly repopulation of Dictyota dichotoma (Hudson) Lamouroux in the inshore waters of North Carolina was studied in the field and in laboratory experiments. It was demonstrated that D. dichotoma is maintained throughout the year at this location and does not require yearly immigrations. A young germling stage was shown to function as the overwintering structure. Although release of aplanospores was unaffected by temperature and photoperiod, subsequent germination and establishment required warm conditions. If germlings were allowed to grow to the 7–9 cell stage under summer conditions, they could survive 21 wk of winter conditions. Transfer of 21 wk old winterized germlings to summer conditions resulted in the rapid production of erect blades. It therefore appears that D. dichotoma maintains its populations near its northern distribution limit on the East Coast of North America by undergoing dormancy after germling establishment.
GROWTH AND PRODUCTION OF LAMINARIA LONGICRURIS (PHAEOPHYTA) POPULATIONS EXPOSED TO DIFFERENT INTENSITIES OF WATER MOVEMENT1
Authors: Gerard Valrie A. , Mann Kenneth H. 
Published: August 2010

ABSTRACTBlade elongation was compared in two populations of Laminaria longicruris de la Pylaie in Shag Bay, Nova Scotia, Canada; one population was exposed to and the other sheltered from high intensity water movement. The maximum and minimum elongation rates were similar for the two populations, but the sheltered coast plants grew more rapidly during 8 mo of the year. Measurements of internal inorganic nitrogen (NO3−+ NO2−) reserves and dry organic weight indicated that low concentrations of dissolved nutrients in summer and low levels of illumination in fall and winter were more limiting to growth at the exposed site than the sheltered site. Transplant experiments provided evidence that morphological differences between the exposed and sheltered coast plants accounted at least partially for their different responses to varying nutrient conditions and light levels. It is concluded that lower productivity of the exposed coast population is the result of adaptation to high intensity water movement.
THE BIOLOGY OFHARVEYELLA MIRABILIS(CRYPTONEMIALES, RHODOPHYCEAE). VII. STRUCTURE AND PROPOSED FUNCTION OF HOST‐PENETRATING CELLS1
Authors: Goff Lynda J. 
Published: August 2010

ABSTRACTThe parasitic red algaHarveyella mirabilis(Reinsch) Schmitz & Reinke was examined by light and electron microscopy to determine the structural mechanism involved in nutrient transfer. The host‐penetrating rhizoidal cells are unique in possessing an extensive and apparently dynamic endomembrane system as well as other unique cytoplasmic inclusions. The membrane system consists of the plasmalemma, pinocytotic vesicles, multivesicular and concentric bodies, endoplasmic reticulum, dictyosomes, micro‐body‐like structures and an extensive vacuolar system. It is proposed that this system is active in the uptake and processing of host‐derived nutrients. Plasmalemmal extensions (plasmalemmavilli) ofHarveyellamedullary cells may also function in nutrient uptake.
EFFECT OF LIGHT QUALITY AND INTENSITY ON GLYCEROL CONTENT INDUNALIELLA TERTIOLECTA(CHLOROPHYCEAE) AND THE RELATIONSHIP TO CELL GROWTH/OSMOREGULATION1
Authors: Jones Thomas W. , Galloway Raymond A. 
Published: August 2010

ABSTRACTDunaliella tertiolectaButcher was grown at two intensities (33, 150μEin · m−2· s−1) of blue light and white light at 0.25, 0.50 and 1.00 M NaCl. Growth rates were used as an indication of the relative osmoregulatory ability of cells in the various treatments. There was no significant effect on growth rate due to various NaCl molarities. No significant difference in growth rate was found between blue‐ and white‐light cultures at the high intensity, the average growth constant being 2.07 divisions/day. However, at the low intensity illumination, blue light produced a significant increase in growth rate; 1.42 vs. 0.93 divisions/day for blue light and white light grown cells respectively. The average glycerol content of exponentially dividing cells grown at 0.25, 0.50 and 1.00 M NaCl was 0.12, 0.41 and 1.12 mg/108cells, respectively, as measured by gas chromatography. The intracellular glycerol content was significantly reduced by blue light at both light intensities and at each NaCl molarity. However, high light intensity reduced cellular glycerol content more than the reduction effected by blue light. Glycerol accumulated in the medium throughout culture growth. Intracellular glycerol content also increased with cellular aging reaching 2.72 mg/108cells in stationary phase, low intensity 1.00 M NaCl cultures. A negative correlation between glycerol content and growth rate was found. Total inhibition of glycerol production could not be obtained by treatment with blue light. However, this negative correlation possibly indicates thatD. tertiolectaexpends energy producing an excess amount of glycerol over that required for osmoregulation, leading to a reduction in the growth rate for the organism.
COMPARISON OF TOXINS IN THREE ISOLATES OF GONYAULAX TAMARENSIS (DINOPHYCEAE)1
Authors: Alam M. I. , Hsu C. P. , Shimizu Y. 
Published: August 2010

ABSTRACTToxicity levels and profiles of three isolates of Gonyaulax tamarensis Lebour grown under the same conditions were compared. One isolate was collected from Ipswich, Massachusetts, during the massive red tide of 1972 along the New England coast. The other two isolates were obtained from Perch Pond (Falmouth, Massachusetts) and Mill Pond (Orleans, Massachusetts) located in the southwest and south of Cape Cod, Massachusetts, respectively. All the three cultures produced toxins with variation in their toxicity levels. Toxin contents were highest in the Ipswich isolate, followed in an order by Mill Pond and Perch Pond cultures. Morphological similarity existed between Ipswich and Mill Pond cells, whereas the Perch Pond cells possessed an additional ventral pore on the l' epithecal plate.
METHYLAMINE UPTAKE IN THE GREEN ALGA CHLORELLA PYRENOIDOSA1
Authors: Pelley Janet Lynn , Bannister T. T. 
Published: August 2010

ABSTRACTMethylamine uptake in nitrogen‐starved Chlorella pyrenoidosa Beij. follows Michaelis‐Menten kinetics: maximum uptake is about 1.6 nmol μl−1· cells · min−1, half‐saturation occurs at 4 μM methylamine, and the slope in the range where uptake is proportional to concentration is 0.4 nmol μl−1· min−1·μM−1. In cells grown in the presence of a non‐limiting nitrogen concentration, methylamine uptake is directly proportional to concentration up to at least 0.5 mM, and the slope is 1/500 that for starved cells. Similar uptake kinetics have been reported for Penicillium chrysogenum and attributed to an inducible “ammonium permease.” Apparently, a similar permease occurs in algae.
TOXICITY OF SUBTROPICAL MARINE ALGAE USING FISH MORTALITY AND RED BLOOD CELL HEMOLYSIS FOR BIOASSAYS1
Authors: Targett Nancy M. , Mitsui Akira 
Published: August 2010

ABSTRACTTwo bioassays (fish mortality and fish erythrocyte hemolysis) were used to survey for the presence of toxic principles in aqueous extracts of 19 species of marine macro‐algae found in south Florida coastal waters. Extracts from six species (Chlorophyta—Anadyomene stellata (Wulfen) C. Ag., Caulerpa prolifera (Forsskål) Lamour., Penicillus capitatus Lamarck: Rhodophyta—Centroceras clavulatum (C. Ag.) Montague, Laurencia papillosa (Forsskål) Grev., L. poitel (Lamour.) Howe) showed lethal toxicity to the spotfin mojarra, Euconistomus argenteus Baird & Girard. Extracts from three species (Chlorophyta—A. stellata: Phaeophyta—Dictyota dichotoma (Hudson) Lamour.: Rhodophyta—Wrangelia penicillata C. Ag.) lysed erythrocytes of sea bream, Archosargus rhomboidalis (L.).
13C AND 15N UPTAKE BY MARINE PHYTOPLANKTON. I. INFLUENCE OF NITROGEN SOURCE AND CONCENTRATION IN LABORATORY CULTURES OF DIATOMS1
Authors: Collos Yves , Slawyk Gerd 
Published: August 2010

ABSTRACTTwo species of marine diatoms, Skeletonema costatum (Grev.) Cleve and Phaeodactylum tricornutum Bohlin were grown in batch and continuous cultures on four different nitrogen compounds (nitrate, nitrite, ammonium, urea). Carbon and nitrogen uptake were measured simultaneously with the stable isotopes 13C and 15N. Nitrogen uptake generally increased with N concentration in the medium, but no clear difference existed between the N sources. Carbon fixation was decreased for up to 5 h following the addition of the N compound. Nitrite generally had the greatest inhibitory effect on C uptake. Carbon‐to‐nitrogen uptake ratios decreased with increasing dissolved N concentration, becoming lower than one in nutrient‐limited cultures. In contrast, batch cultures exhibited C:N uptake ratios greater than one. These effects are essentially short‐term and differ from long‐term influences of the N source on the cellular chemical composition.
SYNCHRONOUS GROWTH OF CHLAMYDOMONAS REINHARDTII (CHLOROPHYCEAE): A REVIEW OF OPTIMAL CONDITIONS1
Authors: Lien Torleiv , Knutsen Gjert 
Published: August 2010

ABSTRACT Chlamydomonas reinhardtii Dangeard was synchronized at optimal growth conditions under a 12:4 LD regime at 35 C and 20,000 lx with serial dilution to a standard starting cell density of (1.4 ± 0.2) × 106 cells/ml. Synchronous growth and division were characterized by measuring cell number, cell volume and size distribution, dry weight, protein, carbon, nitrogen, chlorophyll, carotenoids, nucleic acids, nuclear and cytoplasmic division during the vegetative life cycle. The main properties of the present system are: Exponential growth with high productivity, high degrees of synchrony and reproducibility during repeated life cycles. The degree of synchrony of this light‐dark synchronization system was evaluated and compared with those described in the literature using probit analysis of the time course of DNA synthesis, nuclear and cytoplasmic division and sporulation (increase in cell number). The results showed that the degree of synchrony is highest for cells grown under optimal conditions.
DYNAMICS OF CELLULAR AND EXTRACELLULAR cAMP IN ANABAENA FLOS‐AQUAE (CYANOPHYTA): INTRINSIC CULTURE VARIABILITY AND CORRELATION WITH METABOLIC VARIABLES1
Authors: Francko David A. , Wetzel Robert G. 
Published: August 2010

ABSTRACTThe production and extracellular release of cyclic adenosine 3′: 5′‐monophosphate (cAMP) by the blue‐green alga Anabaena flos‐aquae (Lyngb.) Breb. varied greatly within and between active growth phase and stationary phase and under differing nutrient regimes. Enhanced cellular cAMP production was found in actively growing Anabaena inoculated into media deficient in nitrate or phosphate, or into fresh media containing non‐limiting nutrient concentrations. In stationary phase Anabaena, but not actively growing cells, the concentrations of intra‐cellular cAMP present in cells grown under a variety of nutrient regimes could be significantly correlated to [14C]‐bicarbonate uptake by an exponential relationship.
NEW ENDOLITHIC CYANOPHYTES FROM THE NORTH ATLANTIC OCEAN: I. CYANOSACCUS PIRIFORMIS GEN. ET SP. NOV.1
Authors: Lukas Karen J. , Golubic Stjepko 
Published: August 2010

ABSTRACTThis paper describes a new genus and species of endolithic microorganism, Cyanosaccus piriformis Lukas and Golubic (Cyanophyta, Pleurocapsales). It is characterized by 1) having one to four spherical to pear‐shaped cells within a stalked, gelatinous sheath, 2) its mode of reproduction by release of a large number of baeocytes produced by the proximal daughter cell following transverse binary fission of the parent cell, and 3) its ability to bore into and dwell within carbonate substrates in the marine environment. Its habit of asymmetrical sheath production allies it with the common microboring genera Hyella and Solentia within the family Hyellaceae. Cyanosaccus is a common inhabitant of mollusk shells found in water depths ranging from +0.5 to –75 m MLW on the eastern Florida continental margin and in carbonate sands or rocks in the intertidal and subtidal zones of the Bermuda and Bahama Islands. Its distribution within and among inhabited substrates is patchy due to its mode of reproduction and growth.
PATTERNS OF GROWTH AND CELL COMPOSITION OF FRESHWATER ALGAE IN LIGHT‐LIMITED CONTINUOUS CULTURES1
Authors: Schlesinger David A. , Shuter Brian J. 
Published: August 2010

ABSTRACT Selenastrum minutum (Näg.) Collins and three species of Scenedesmus were grown in light‐limited continuous cultures. Comparative growth patterns were explained in terms of differences in the rates of light absorption and utilization. For all species, increasing light intensity or lowering temperature caused chl a/C to decrease and RNA/C to increase. Similar shifts in pigment composition have been widely reported. However, the RNA:light interaction has only been reported infrequently, and the RNA:temperature interaction is believed to be the first reported observation of its kind in algae. Distinct differences in RNA/C among the test algae may be size‐dependent. Similar environmentally induced shifts in chl a/C and RNA/C among all test algae point to the existence of a common control mechanism which maximizes the specific growth rate through adjustments to cell composition.
CHLOROPHYLL‐SPECIFIC PHOTOSYNTHESIS AND QUANTUM EFFICIENCY AT SUBSATURATING LIGHT INTENSITIES12
Authors: Welschmeyer Nicholas A. , Lorenzen Carl J. 
Published: August 2010

ABSTRACTLight‐limited rates of photosynthesis normalized for chlorophyll a, (α), and actual photon absorption (quantum efficiency, Ф) were determined for six eponentially growing algal species grown under identical conditions. The same parameters, α and Ф, were also monitored for a single diatom species, Thalassiosira pseudonana Hasle & Heimdal, through its growth cycle in batch culture. Statistical differences in α could be demonstrated among the six different exponentially growing species while no differences could be shown for Ф. Statistical differences among the six species were minimized when photosynthetic rates were normalized for in vivo fluorescence rather than extracted chlorophyll a. Both α and Ф were constant while T. pseudonana was in the exponential phase of growth, but both declined as the culture entered stationary phase. While cells were in exponential growth, differences in a were attributed to varying rates of in vivo light absorption per chlorophyll a, thus providing experimental evidence that the in vivo chlorophyll a extinction coefficient, kc (m2· mg Chl a−1), cannot be assumed constant.
SORPTION OF PLUTONIUM‐237 BY TWO SPECIES OF MARINE PHYTOPLANKTON11
Authors: Yen Jeannette 
Published: August 2010

ABSTRACTThe adsorption of plutonium‐237, added from an acid solution, by two species of marine phytoplankton, Monochrysis lutheri Droop, a flagellated chrysomonad, and Phaeodactylum tricornutum Bohlin, a diatom, is governed by a passive mechanism. This is clearly indicated by the observation that the rapid rates of sorption were not significantly different for live and heat‐killed cells incubated at 24°C and 0°C. The Q10 values for the chrysomonad and the diatom of 0.95 and 1.18, respectively, are indicative of passive processes. The average ratio of (activity on algae/activity in filtrate) per unit volume at 24 h, the time when maximum levels of algal radioactivity were attained, of (32 ± 4) × 103 was not significantly different for the diatom or the chrysomonad. On a per cell basis, maximum levels of radioactivity were attained within 2 h. Less than 20% of the adsorbed 237Pu desorbed after 24 h.
PHYCOLOGIA TRIGINTA QUINQUE1,2
Authors: Parker Bruce C. 
Published: August 2010

ABSTRACTA brief history of the origin of the Phycological Society of America (PSA) is presented. Since its founding, the PSA has grown from the 157 Charter Members in 1947 into a vital Society of some 1800 members today. A major catalyst in the development of the PSA was the creation in 1965 of the Journal of Phycology which now ranks among the important journals in Botany. Lists of Charter Members, Distinguished Lecturers, recipients of the Bold Award, members of the PSA Executive Committee and the major meeting sites are included.
DIPLOIDY IN DNA CONTENT IN VEGETATIVE CELLS OF CLOSTERIUM EHRENBERGII (CHLOROPHYTA)1
Authors: Hamada Jin 
Published: August 2010

ABSTRACTDNA content of the nucleus in the placoderm desmid, Closterium ehrenbergii Meneghini was measured throughout the life cycle by epifluorescence microspectrophotometry after DNA specific dye [4′,6‐diamidino‐2‐phenylindol (DAPI)] staining. Postulating a mean DNA content of gamete nuclei as 1C, the nucleus of a newly divided vegetative cell was 2C. Most vegetative cells in the stage of exponential growth had a DNA content from 2C to 4C, while most in stationary phase, with the highest frequency of zygote formation, were 2C. They became pre‐gametes (2C) upon mixing two heterothallic strains. Four gametes were made by a DNA reduction division of each pre‐gamete cell. Therefore, there was a nonmeiotic DNA reduction stage by one half.During germination, the zygote underwent meiosis to produce two gones, each of which contained one surviving nucleus (large nucleus) and one degenerating nucleus (small nucleus). The DNA content of these four nuclei was 1C basically. The DNA of the surviving nucleus duplicated to 2C and further quadruplicated to 4C without cell or nuclear division. These two 4C gones had different cell morphology from ordinary vegetative cells. After the first cell division following meiosis, each gone produced two vegetative cells in which the DNA content became 2C to 4C again.
SHORT TERM UPTAKE OF NUTRIENTS BY ENTEROMORPHA PROLIFERA (CHLOROPHYCEAE)1
Authors: O'Brien Margaret C. , Wheeler Patricia A. 
Published: August 2010

ABSTRACTRates of NH4+ and NO3− uptake were determined by accumulation of 15N in plant tissue and by disappearance of nutrient from the medium. Agreement between rates calculated by the two methods was good, averaging 82.7% (SD = 15.8%) and 91.2% (SD = 13.7%) for NH4+ and NO3− uptake, respectively. An average of 93.4 and 96.0% of added 15NH4+ and 15NO3− was recovered from the medium and /or plant tissue at the end of the incubations. Both bacterial uptake and regeneration of NH4+ may contribute to discrepancies between NH4+ uptake rates calculated by 15N accumulation and disappearance of NH4+ from the medium.The influence of tissue composition on uptake of NH4+, NO3− and PO43‐ by Enteromorpha prolifera (Müller) J. Agardh was examined. For NH4+ uptake, Vmax was 188 μmol NH4+. g dry wt−1. h−1 and Ks ranged from 9.3 to 13.4 μM, but there was no correlation between kinetic parameters and tissue nitrogen content. For NO3−, both kinetic parameters were higher for plants with low tissue nitrogen than for plants with high tissue nitrogen. Maximum rates were 169 and 75.4 μmol NO3−. g dry wt−1. h−1, and Ks was 13.3 and 2.31 μM for low and high tissue nitrogen plants, respectively. Estimates of uptake in the field suggested that NH4+ accounted for 65% and NO3− for up to 35% of total nitrogen uptake during the summer. Nutrient uptake rates of field‐collected plants also indicated that E. prolifera in Yaquina Bay, Oregon was not likely to have been nitrogen‐limited, but may have been phosphorus‐limited.
THE RELATIONSHIP BETWEEN VALVE DIAMETER AND NUMBER OF CENTRAL FULTOPORTULAE IN THALASSIOSIRA WEISSFLOGII (BACILLARIOPHYCEAE)1
Authors: Johansen Jeffrey R. , Theriot Edward 
Published: August 2010

ABSTRACTCells well below the reported minimum size for Thalassiosira weisslogii (Grunow) Fryxell et Hasle were observed in two unialgal cultures. The relationship between diameter and number of central fultoportulae was found to be very regular. Regresion analysis of three different populations showed equivalent slopes and r2 values above 80%. The y‐intercepts were significantly different and support observations in the litrature that nonmarine valeve of T. Weissflogii have fewer central fultoportulae than marine forms.
CELL WALL STRUCTURE AND IRON DISTRIBUTION IN THE GREEN ALGA STAURASTRUM LUETKEMUELLERI (DESMIDIACEAE)1
Authors: Andersen Sissel , Heldal Mikal , Knutsen Gjert 
Published: August 2010

ABSTRACTThe cell wall of Staurastrum luetkemuelleri Donnat & Ruttner was examined with scanning electron microscope (SEM) using whole cells, in thin sections with transmission electron microscope (TEM), and in air dried whole cells and unstained thin sections with X‐ray microanalysis in the scanning‐transmission electron microscope (STEM).The cell wall was ornamented with spines and wartlike structures. Spines were solid structures, consisting of deposits of cell wall material between two main cell wall layers. The wart‐like structures were pore organs extending through the cell wall and the mucilaginous layer outside the cell wall. The pore cylinder was surrounded by deposits of cell wall material similar to the ones in the spines.X‐ray microanalysis of selected areas on whole cells from a natural population showed iron accumulation in discrete locations on the cell extensions of S. luetkemuelleri. In the unstained thin sections iron was found only in the cell wall deposits in the spines. Cells grown in laboratory cultures failed to show iron accumulation regardless of readdition of iron‐EDTA (Fe‐EDTA) to the culture medium.