EXCRETION OF COLORED ULTRAVIOLET-ABSORBING SUBSTANCES BY MARINE ALGAE

1964 ◽  
Vol 42 (1) ◽  
pp. 23-33 ◽  
Author(s):  
J. S. Craigie ◽  
J. McLachlan
Keyword(s):  
Ultraviolet Light ◽  
Alkaline Hydrolysis ◽  
Marine Algae ◽  
Elevated Temperatures ◽  
Surrounding Medium ◽  
Fucus Vesiculosus ◽  
Small Decrease

Normal, healthy thalli of Fucus vesiculosus have been shown to release into the surrounding medium yellow compounds which absorb ultraviolet light. A study of this phenomenon revealed that brief exposure to elevated temperatures (20 °C) increased the amount of pigment released. There was no difference in the production in light or darkness and only a small decrease with reduced salinity. The amount of pigmentation observed in the medium was directly proportional to the degree of alkalinity from pH 7 to pH 9.A number of other macrophytes and microphytes were examined and only those possessing physodes released substances giving a spectrum similar to that of F. vesiculosus.Isolation of the material, alkaline hydrolysis, and chromatography revealed phloroglucinol and several unidentified fluorescent substances. It appears that these materials were flavonols or catechin-type tannins.

PHOTOSYNTHESIS AND METABOLISM IN MARINE ALGAE: VII. PRODUCTS OF PHOTOSYNTHESIS IN FRONDS OF FUCUS VESICULOSUS AND THEIR USE IN RESPIRATION

1967 ◽  
Vol 45 (9) ◽  
pp. 1557-1565 ◽  
Author(s):  
R. G. S. Bidwell
Keyword(s):  
Sodium Carbonate ◽  
Marine Algae ◽  
Fucus Vesiculosus ◽  
Complex Compounds ◽  
Major Product ◽  
Dilute Acid ◽  
Active Metabolites

Samples of Fucus vesiculcsus fronds were permitted to assimilate 14CO2 for 5 h and were then maintained in alternating periods of light and darkness for 3 days. Samples were collected at intervals, and the radioactivity of various simple and complex compounds was measured. The major product of photosynthesis was mannitol; relatively small amounts of 14C entered other compounds. From its behavior, it appears that mannitol is the major substrate of respiration in these plants; there may be secondary substrates among the complex polysaccharides. The complex polysaccharides are not formed directly from mannitol in light, but from some common precursors, or else from a small isolated pool of mannitol which is separated from the main cellular supplies. In darkness, the complex polysaccharides appear to be derived from stored mannitol. One of the more active metabolites, judged from its behavior, is a component of the residue left after dilute acid and sodium carbonate extraction. This component undergoes turnover, i.e. breakdown and resynthesis from newly-acquired photosynthate in the light, and is formed from stored photosynthate in the darkness.

KINETICS OF THE AQUEOUS ALKALINE HOMOGENOUS HYDROLYSIS OF HIGH EXPLOSIVE 1, 3,5,7-TETRAAZA- 1, 3,5,7-TETRANITROCYCLOOCTANE (HMX)

1994 ◽  
Vol 30 (3) ◽  
pp. 53-61 ◽  
Author(s):  
Harro M. Heilmann ◽  
Michael K. Stenstrom ◽  
Rolf P. X. Hesselmann ◽  
Udo Wiesmann
Keyword(s):  
Temperature Dependence ◽  
Alkaline Hydrolysis ◽  
Rate Constants ◽  
Elevated Temperatures ◽  
Second Order ◽  
Order Rate ◽  
Subsequent Calculation ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Order Rate Equation

In order to get basic data for the design of a novel treatment scheme for high explosives we investigated the kinetics for the aqueous alkaline hydrolysis of 1,3,5,7-tetraaza-1,3,5,7-tetranitrocyclooctane (HMX) and the temperature dependence of the rate constants. We used an HPLC procedure for the analysis of HMX. All experimental data could be fit accurately to a pseudo first-order rate equation and subsequent calculation of second-order rate constants was also precise. Temperature dependence could be modeled with the Arrhenius equation. An increase of 10°C led to an average increase in the second-order rate constants by the 3.16 fold. The activation energy of the second-order reaction was determined to be 111.9 ±0.76 kJ·moJ‒1. We found the alkaline hydrolysis to be rapid (less than 2.5% of the initial HMX-concentration left after 100 minutes) at base concentrations of 23 mmol oH‒/L and elevated temperatures between 60 and 80°C.

Photosynthesis and metabolism of marine algae. VIII. Incorporation of 14C into the polysaccharides metabolized by Fucus vesiculosus during pulse labeling experiments

1972 ◽  
Vol 50 (1) ◽  
pp. 191-197 ◽  
Author(s):  
R. G. S. Bidwell ◽  
Elizabeth Percival ◽  
Berit Smestad
Keyword(s):  
Molecular Weight ◽  
Sequential Extraction ◽  
Marine Algae ◽  
Alginic Acid ◽  
Fucus Vesiculosus ◽  
Fresh Medium ◽  
Low Molecular Weight ◽  
Acid Extract ◽  
Highly Active ◽  
Residual Material

Samples of Fucus vesiculosus fronds were allowed to assimilate 14CO2 for 10 min and 3 h. In a second experiment fronds were allowed to grow for 10 min in 14CO2 and were then transferred to fresh medium containing 12CO2. Samples were taken immediately, after 30 min, and after 2 h. Sequential extraction and fractionation of the polysaccharides from each of the five samples gave 14C-labeled laminaran, xylogalactofucoglucuronan (A), xyloglucuronogalactofucan (B) (these polysaccharides are named in the order of the increasing proportions of their constituent sugars), fucoidan (C), alginic acid, and residual polysaccharide material containing mainly glucose with some galactose. The activities of each of the polysaccharides, the residual material, and their constituent sugars were measured. Highly active low molecular weight carbohydrates, present in the acid extract, are the suggested precursors of the polysaccharides. The fucose-containing polysaccharides represent the extremes of a family of polymers; it is postulated from these studies that (A) is transformed into fucoidan via polysaccharide (B) in this alga.

Colourfast pigments in silicone hand and maxillofacial prostheses

2002 ◽  
Vol 26 (2) ◽  
pp. 124-134 ◽  
Author(s):  
M. E. L. Leow ◽  
R. K. K. Ow ◽  
S. Valiyaveettil ◽  
M. H. Lee ◽  
R. W. H. Pho
Keyword(s):  
Elevated Temperature ◽  
Ultraviolet Light ◽  
Normal Saline ◽  
Elevated Temperatures ◽  
Colour Change ◽  
Clinical Problem ◽  
Blue Pigment ◽  
Saline Solutions ◽  
Control Samples

This study addresses the clinical problem of long-term discolouration of silicone hand and maxillofacial prostheses. Seven (7) pigment hues, considered essential for achieving a suitable tissue colour-matched prosthesis, were compared for their colourfast property, across three selected proprietary formulations. In all, a series of 21 pigments, were tested for colourfastness. The pigments, presenting as suspensions (PS), pastes (PP) and dry pigments (PD), were exposed, over nine months, to ultraviolet light, elevated temperatures and varying concentrations of salinity. Colour change of the pigments was measured and expressed as Commission International de l'Eclairage (CIE) (L∗, a∗, b∗) units. Pigment discoloration was significantly attributed to ultraviolet light. Pigmented and clear silicone samples showed a “yellowing” (+Δb∗) effect. Lighter pigments became darker (-ΔL∗) in shade. Pigment samples at the elevated temperature of 50°C showed significant but small colour change (?E, 0.77 to 3.63). Only the master blue pigment (PS-4) recorded a higher ?E, 6.26 at 50°C. At a moderate temperature of 35°C, both pigmented and clear silicone test samples remained relatively colourfast. Comparison was made to control samples, stored in darkness, at 26°C. The pigments were generally colourfast (ΔE<6 units) to saline solutions of 0.15M and 5.0M concentrations. Only the monastral red (PD-3) pigment recorded a ΔE of 9.33, in 0.15M normal saline, simulating the vulnerability of this pigment to the salinity of human sweat. Pigment hues were systematically ranked according to colourfastness. Pigment suspensions were more colourfast than pigment pastes.

PHOTOSYNTHESIS AND METABOLISM OF MARINE ALGAE: V. RESPIRATION AND METABOLISM OF C14-LABELLED GLUCOSE AND ORGANIC ACIDS SUPPLIED TO FUCUS VESICULOSUS

1963 ◽  
Vol 41 (1) ◽  
pp. 155-163 ◽  
Author(s):  
R. G. S. Bldwell ◽  
N. R. Ghosh
Keyword(s):  
Organic Acids ◽  
Marine Algae ◽  
Alginic Acid ◽  
Fucus Vesiculosus ◽  
Alcohol Extract ◽  
Sodium Salts ◽  
Uptake And Metabolism

Fronds of F. vesiculosus were supplied with glucose-UL-C14, pyruvate-2-C14, acetate-1-C14, acetate-2-C14, or formate-C14, the acids being presented as the sodium salts. The radioactivity of various fractions of the fronds as well as respired CO2 was determined after various times, and the distribution of radioactivity among the compounds present in the alcohol extract was determined. The contribution of glucose to respired CO2 was much less than that of the organic acids. However, although its uptake and metabolism were less, a large proportion of the glucose that was metabolized was converted to CO2. Glucose contributed somewhat to polysaccharides, but the organic acids were much better precursors of alginic acid. The pattern of labelling among soluble compounds, of which glycerol was especially prominent, indicated that several pathways of metabolism operated, involving both carboxylation and decarboxylation reactions.

Destruction of Iron-Complexed Cyanide by Alkaline Hydrolysis

1989 ◽  
Vol 21 (6-7) ◽  
pp. 547-558 ◽  
Author(s):  
Stephen J. Robuck ◽  
Richard G. Luthy
Keyword(s):  
Alkaline Hydrolysis ◽  
Elevated Temperatures ◽  
Appropriate Technology ◽  
Industrial Wastes ◽  
Hydrolysis Reaction ◽  
Hydrolysis Rate ◽  
Aluminum Reduction ◽  
Metal Cyanide ◽  
Alkaline Conditions ◽  
Cyanide Complexes

Iron-complexed cyanide compounds are found in various industrial wastes, and are resistant to destruction by conventional technologies used to treat cyanide-bearing wastes. This study evaluated hydrolytic destruction of iron-complexed cyanide in leachates from land disposal of spent carbonanceous material used to line aluminum reduction cells. The investigation showed that iron-cyanide complexes may be hydrolyzed under alkaline conditions at elevated temperatures and pressures, e.g. in the range of 165-180 °C and 100-150 psig. The hydrolysis reaction is apparently first-order with respect to total cyanide. The reaction yields stoichiometric amounts of ammonia and formate, and Fe3O4(s). The rate of the reaction is especially temperature dependent, and for the case of spent potlining leachate, the hydrolysis rate may be estimated by an Arrhenius kinetic expression for hydrolysis of simple cyanide. The rate of the hydrolysis reaction for iron-complexed cyanide is compared to that for other metal-cyanide complexes. It is shown that waste composition may affect the hydrolysis rate, and that the instability of certain metal-cyanide complexes with respect to alkaline chlorination does not correlate with instability with respect to alkaline hydrolysis. Alkaline hydrolysis is an appropriate technology for destruction of iron- and other metal-cyanide compounds in wastes at high concentrations.

DARK FIXATION OF C14-BICARBONATE BY MARINE ALGAE

1963 ◽  
Vol 41 (3) ◽  
pp. 317-325 ◽  
Author(s):  
J. S. Craigie
Keyword(s):  
Organic Acids ◽  
Marine Algae ◽  
Total Radioactivity ◽  
Fucus Vesiculosus ◽  
Artificial Seawater ◽  
Dark Fixation

The ability of several multicellular marine algae to remove NaHC14O3 from seawater in darkness has been compared. Members of the Phaeophyta removed approximately four to eight times more isotope than did members of the Rhodophyta and Chlorophyta examined. After 2 minutes of dark fixation, aspartic and glutamic acids were the main compounds identified in both Fucus vesiculosus and Polysiphonia lanosa. Radioactivity appeared largely in citric plus isocitric acids in Fucus, whereas radioactive organic acids were not detected in Polysiphonia even after 30 minutes. Fractionation of F. vesiculosus after 2 hours of dark fixation showed that 95% of the total radioactivity recovered occurred in the fraction soluble in 70% acetone.Twenty-four hours of darkness immediately prior to a 2-hour dark fixation period reduced the total radioactivity incorporated to almost one-half of the control values. Either artificial seawater (one-fifth natural salinity) or a medium in which NaCl was substituted by KCl had little effect on the total radioactivity fixed during darkness. The distribution of isotope, however, showed some alterations.

PHOTOSYNTHESIS AND METABOLISM IN MARINE ALGAE: IV. THE FATE OF C14-MANNITOL IN FUCUS VESICULOSUS

1962 ◽  
Vol 40 (6) ◽  
pp. 803-807 ◽  
Author(s):  
R. G. S. Bidwell ◽  
N. R. Ghosh
Keyword(s):  
Active Metabolite ◽  
Marine Algae ◽  
Fucus Vesiculosus ◽  
Dilute Acid ◽  
Other Substances

C14-mannitol was supplied to fronds of F. vesiculosus, and its conversion into CO2 and other compounds was studied. Only small amounts of the mannitol taken in were metabolized. Mannitol is apparently not an immediate substrate of respiration, but in time it may be converted into some other substances which are. Dilute acid-soluble polysaccharides acquired small amounts of radioactivity, but most of the mannitol which underwent metabolism was eventually converted to residual carbohydrates. It is concluded that mannitol is probably a storage compound rather than an active metabolite.

scholarly journals The opportunities for obtaining of the biogas on methane fermentation from marine algae biomass and water plant biomass

2018 ◽  
Vol 10 ◽  
pp. 01007
Author(s):  
Ewa Jachniak ◽  
Joanna Chmura ◽  
Mariusz Kuglarz ◽  
Józef Wiktor
Keyword(s):  
Marine Algae ◽  
Plant Biomass ◽  
Organic Matter Content ◽  
Fucus Vesiculosus ◽  
Matter Content ◽  
Dry Matter Content ◽  
Methane Fermentation ◽  
Algae Biomass ◽  
Water Plant ◽  
Potamogeton Perfoliatus

The aim of the research was to try to obtain of the biogas on a laboratory scale from marine algae biomass and water plant biomass. The research was conducted in 2016 year and samples were taken from the Polish coast of the Baltic Sea. In laboratory work, algae and plant species were first identified. The next, in order to subject them to methane fermentation processes and to obtain biogas,partial mechanical treatment of the biomass was conducted. Dry matter content and dry organic matter content were also determined. The research has shown different production of the biogas depending on the various species of the algae and plants. The percentage composition of the biogas was also determined (% CO2 and % CH4). In this research some kinds and species of algae and aquatic plants were distinguished: Scytosiphon cf. S. tortilis, Fucus vesiculosus, Cladophora, Audouinella, Potamogeton perfoliatus. Production of biogas from selected algae and water plants oscillated between 0.023 dm3·g-1 and 0.303 dm3·g-1. The highest content of the methane in biogas was obtained from the mixture of Ectocarpus from spring and autumn harvest (values oscillated from 80.7 % to 81.2 %), while the highest percentage share of carbon dioxide in the biogas was characterized by the mixture Fucus vesiculosus and Audouinella (22 %). Due to a small amount of the research in this field, more research is needed.

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