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OPTIMUM CONDITIONS FOR PHOTOSYNTHESIS IN OPTICALLY DENSE CULTURES OF ALGAE
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CHARACTERISTICS OF THE PROCESS OF AGING IN ALGAE CELLS
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A new Chroococcacean alga from the Proterozoic of Queensland.
Microstructure of Proterozoic nannofossils bracketed by dated granitic events compared with living Eucapsis of blue green Chroococcaceae algal family
The Botryococcenes-hydrocarbons of novel structure from the alga Botryococcus braunii, Kuetzing
Hydrocarbon fraction examination of Botryococcus brauniis growing in natural environment, discussing unsaturated isomeric hydrocarbons
Preliminary report on the dispersal of thermophilic algae to Surtsey
Investigating water transport scheme for dispersal of thermophilic microorganisms to Surtsey from mainland areas
Photorecovery of gamma irradiated cultures of blue-green alga, Anacystis nidulans.
Evidence is given for photorecovery of Anacystis nidulans after exposures to Co 60 gamma radiation. After irradiation the levels of viable cells were higher in cultures kept in white light than in cultures kept dark for 24 hr. The post-irradiation survival rate increase after 30-min exposures to visible light is demonstrated in cultures irradiated with 35 krad. An increase in survival rates was not observed after exposures to ?red' light.
Isolation and characterization of ultraviolet light-sensitive mutants of the blue-green alga Anacystis nidulans.
Three independently isolated ultraviolet light sensitive (uvs) mutants of Anacystis nidulans were characterized. Strain uvs-1 showed the highest sensitivity to UV by its greatly reduced photoreactivation capacity following irradiation. Pretreatment with caffeine suppressed the dark-survival curve of strain uvs-1, thus indicating the presence of excision enzymes involved in dark repair. Under 'black' and 'white' illumination, strain uvs-1 shows photorecovery properties comparable with wild-type cultures. Results indicate that strains uvs-1, uvs-35, and uvs-88 are probably genetically distinct UV-sensitive mutants.
Ultrastructure and geologic relations of some two-aeon old Nostocacean algae from northeastern Minnesota.
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Variable photosynthetic units, energy transfer and light-induced evolution of hydrogen in algae and bacteria.
The present state of knowledge regarding the truly photochemical reactions in photosynthesis is considered. Nine-tenths of the available knowledge is of a biochemical nature. Questions regarding the activities of the chlorophyll system are examined. The simplest photochemical response observed in living hydrogen-adapted algal cells is the release of molecular hydrogen, which continues even after all other known natural reactions have been eliminated either by heating or the action of poisons.
Effect of nitrite and nitrate on chlorophyll fluorescence in green algae.
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Thermal alteration of blue-green algae and blue-green algal chlorophyll
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Accumulation of blue-green algae in the surface water of the northern Baltic, 6 August 1975, generated from the CCT-tape MSS 5 (ID 2196-0917200) by a Hertz ink-jet plotter connected to a APDP 11/40 computer at FOA 3
There are no author-identified significant results in this report.
Laser induced fluoroescence from algae: Results of a ship-borne field test
A basis is provided for the feasibility of air-borne laser fluorosensing not only of chlorophyll but also of pollutants such as oils and chemicals. There was a satisfactory correlation between the laser data and those obtained manually. The absolute determination of the chlorophyll concentration is discussed.
Origin and evolution of osmoregulatory mechanisms in blue-green algae as a function of metabolic and structural complexity: Reflections of precambrian paleobiology
Twenty-four of the twenty-nine cyanobacteria proposed for culture were successfully cultured. Betaines are discussed.
Identification of a volatile phytotoxin from algae
The objectives were to develop a trap system for isolating fractions of volatile algal phytotoxin and to characterize the major components of the isolated phytotoxin fractions. A bioassay using Phaseolus vulgaris seedlings was developed to aid in investigating the properties of the phytotoxin produced by cultures of Euglena gracilis var. bacillaris and Chlorella vulgaris. Two traps were found, 1.0 M hydrochloric acid and 0 C, which removed the phytotoxin from the algal effluent and which could be treated to release that phytotoxin as judged with the bioassay procedure. It was also determined that pretraps of 1.0 M sodium hydroxide and 1.0 M potassium biocarbonate could be used without lowering the phytotoxin effect. Ammonia was identified in trap solutions by ninhydrin reaction, indophenol reaction and derivatization with dansyl chloride and phenylisothiocyanate. Ammonia at the gaseous concentrations detected was found to have the same effects in the bioassay system as the volatile phytotoxin. It is possible that other basic, nitrogen containing compounds which augment the effects of ammonia were present at lower concentrations in the algal effluent.
Distribution of snow and ice algae in western North America
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The role of sulfur in osmoregulation and salinity tolerance in cyanobacteria, algae, and plants
Organosulfur compounds are involved in osmoregulation and salinity tolerance in some cyanobacteria and photosynthetic eukaryotes. Glycinebetaine, the osmolyte of the halotolerant cyanobacterium, Aphanothece halophytica, requires the sulfonium compound. S-adenosyl-methionine (SAM) for its synthesis. Glutamate is the nitrogen source, SAM is the methyl carbon and serine the carbon backbone source of this unique osmolyte. Inhibitor studies suggest that photorespiration interacts with sulfur metabolism to control betaine synthesis in cyanobacteria. The limiting factor for SAM synthesis is formate from photorespiration. SAM is, in turn, the methyl donor for betaine synthesis from serine. The nitrogen component of serine is from glutamate. Betaine synthesis is hypothesized to be regulated via potassium. The biosynthesis of dimethyl-B-propiothetin (DMPT, which is the same as beta-dimethyl sulfonioprpionate) and diacylsulfoquinovosylglycerol were elucidated as having their roles in osmoregulation and salinity tolerance. The relation between these sulfolipids and the sulfur cycle was discussed.