scholarly journals Sterol composition of the Adriatic sea algae Ulva lactuca, Codium dichotomum, Cystoseira adriatica and Fucus virsoides

2005 ◽  
Vol 70 (12) ◽  
pp. 1395-1400 ◽  
Author(s):  
Radomir Kapetanovic ◽  
Dusan Sladic ◽  
Simeon Popov ◽  
Mario Zlatovic ◽  
Zoran Kljajic ◽  
...  

The sterol composition of two green algae and two brown algae from the South Adriatic was determined. In the green alga Ulva lactuca, the principal sterols were cholesterol and isofucosterol. In the brown alga Cystoseira adriatica, the main sterols were cholesterol and stigmast-5-en-3?-ol, while the characteristic sterol of the brown algae, fucosterol, was found only in low concentration. The sterol fractions of the green alga Codium dichotomum and the brown alga Fucus virsoides contained practically only one sterol each, comprising more than 90 % of the total sterols (clerosterol in the former and fucosterol in the latter).

2019 ◽  
Vol 40 (1) ◽  
pp. 82-88
Author(s):  
Colin L McLay

Abstract Cryptodromia fallax (Latreille in Milbert, 1812) has been serendipitously found again on the island of Mauritius, almost 200 yrs after its discovery. The new material provides new information about the structure of the female sternum, providing stronger evidence that a new genus, Alcockdromiagen. nov., is required. Observations show that this crab cuts out and carries pieces of seaweed in the manner of a paraglider, rather than pieces of sponge normally carried by dromiid crabs. The crab uses Ulva lactuca Linnaeus, a green alga, and Lobophora variegata (J.V. Lamouroux), a brown alga. This discovery shows that the last two prehensile dromiid pereopods, which are used to carry soft camouflage, are multi-purpose, having only minor structural differences allowing them to carry seaweeds.


1998 ◽  
Vol 72 (6) ◽  
pp. 1072-1086 ◽  
Author(s):  
Shuhai Xiao ◽  
Andrew H. Knoll ◽  
Xunlai Yuan

On the basis of morphological and taphonomic study of a large sample population,Miaohephyton bifurcatumSteiner, emend. from the terminal Proterozoic Doushantuo Formation (600-550 Ma), South China, is interpreted as algal fragments shed from their parent thalli for reproductive or environmental reasons. Characters such as regularly dichotomous, multicellular thalli with forked tips, apical and intercalary meristematic growth, abscission structures, and possible conceptacles collectively suggest an affinity with the brown algae, in particular the order Fucales. In conjunction with reports of xanthophyte fossils in older Neoproterozoic rocks, this reinterpretation ofMiaohephyton bifurcatumindicates that photosynthetic stramenopiles (chrysophytes, synurophytes, xanthophytes, phaeophytes, and diatoms; or chromophytes sensu stricto) diversified during the Neoproterozoic Era along with the red and green algae. This, in turn, suggests that the secondary endosymbiosis that gave rise to the photosynthetic stramenopiles took place relatively soon after the evolutionary transformation of cyanobacteria to rhodophyte plastids.


2020 ◽  
Vol 63 (6) ◽  
pp. 541-549
Author(s):  
Chenlin Liu ◽  
Xiuliang Wang

AbstractThe Antarctic endemic brown alga Ascoseira mirabilis is physically and physiologically well adapted to the extreme polar environment. To better understand the molecular strategies associated with stress adaptation, the transcriptome of A. mirabilis was sequenced, and its antioxidant enzyme genes were identified and compared with other algae. A total of 126,576 unigenes with a mean length of 734 bp and N50 of 1174 bp was assembled from the transcriptome data. Phylogenetic analysis revealed that dramatic evolutionary changes had occurred in the brown algal superoxide dismutases (SODs) and class I peroxidases that were not consistent with the phylogeny of the species. Fe/Mn SODs are more prevalent in brown algae than in red and green algae. Two additional Fe-SODs in A. mirabilis were phylogenetically closely related to those of green algae, but not to those in other brown algae. We also identified three A. mirabilis ascorbate peroxidase (APx) genes that had a different origin from other brown algal APxs. The SOD and APx genes specifically identified in A. mirabilis will be crucial for understanding the evolution of the algal antioxidant enzymes that contribute to ecological success under extreme environmental conditions in the Antarctic region.


2018 ◽  
Vol 69 (5) ◽  
pp. 1089-1098
Author(s):  
Elena Suzana Biris Dorhoi ◽  
Maria Tofana ◽  
Simona Maria Chis ◽  
Carmen Elena Lupu ◽  
Ticuta Negreanu Pirjol

The valorification of the marine biomass is an important resource for many industries like pharmaceutical, supplying raw material for the extraction of bioactive substances (vitamins, sterols and collagen), cosmetics, biofertilizers and wastewater treatment. In the last years a special attention has been given to the use of macroalgae. The aim of this study was to emphasize the capacity of two representative green algae species frequent presents on the Romanian shore, Ulva lactuca (L.) and Cladophora vagabunda (L.) Hoek, to remove two usual detergents from wastewater. The green algae washed, dried at room temperature, macerated to powder were introduced into different filter paper for comparison, then immersed in waste water treated with different concentrations of detergents. Tap water was used for the experiment. The results show that Ulva lactuca (L.) species is suitable than Cladophora vagabunda (L.) Hoek species, for wastewater treatment.


2021 ◽  
Author(s):  
Aleksandra Huter ◽  
Dragana Drakulović ◽  
Sandra Jokanović

1958 ◽  
Vol 42 (2) ◽  
pp. 243-250 ◽  
Author(s):  
G. C. McLeod

Action spectra for delayed light production by several algae were determined from 250 to 750 mµ incident light. In the visible portion of the spectrum the action spectra resemble those reported by previous workers for photosynthesis and light emission. Blue-green algae had a maximum at 620 mµ, red algae at 550 mµ, whereas green and brown algae have action spectra corresponding to chlorophyll and carotenoid absorption. In the ultraviolet portion of the spectrum delayed light is emitted by algae down to 250 mµ incident light. The action spectra of the different algae are not alike in the ultraviolet portion of the spectrum. This indicates that pigments other than chlorophyll must be sensitizing or shielding the algae in the ultraviolet region.


Author(s):  
Xiaoqing Li ◽  
Yihan Chen ◽  
Xiaoxiang Gao ◽  
Yijing Wu ◽  
Hesham Rushdy El-Seedi ◽  
...  
Keyword(s):  

2014 ◽  
Vol 21 (1) ◽  
pp. 95-106
Author(s):  
Luka Mudronja ◽  
Marko Katalinić ◽  
Rino Bošnjak ◽  
Pero Vidan ◽  
Joško Parunov

AbstractThis paper presents operability guidelines for seafarers on a product tanker which navigates in the Adriatic Sea during heavy weather. Tanker route starts from the Otranto strait in the south to the island Krk in the north of Adriatic Sea. Heavy weather is caused by south wind called jugo (blowing from E-SE to SS-E, sirocco family). Operability guidelines are given based on an operability criteria platform for presenting ship seakeeping characteristics. Operability criteria considered in this paper are propeller emergence, deck wetness and bow acceleration of a product tanker. Limiting values of mentioned criteria determine sustainable speed. Heavy weather is described by extreme sea state of 7.5 m wave height. Wave spectrum used in this paper is Tabain spectrum which is developed specifically for Adriatic Sea. Seafarer's approach of decisions making in extreme weather is also shown and servers as a guideline for further research of the authors.


2014 ◽  
Vol 11 (1) ◽  
pp. 331-390
Author(s):  
M. Lipizer ◽  
E. Partescano ◽  
A. Rabitti ◽  
A. Giorgetti ◽  
A. Crise

Abstract. An updated climatology, based on a comprehensive dataset (1911–2009) of temperature, salinity and dissolved oxygen, has been produced for the whole Adriatic Sea with the Variational Inverse Method using the DIVA software. Climatological maps were produced at 26 levels and validated with Ordinary Cross Validation and with real vs. synthetic Temperature–Salinity diagram intercomparison. The concept of Climatology–Observation Misfit (COM) has been introduced as an estimate of the physical variability associated with the climatological structures. In order to verify the temporal stability of the climatology, long-term variability has been investigated in the Mid Adriatic and the South Adriatic Pits, regarded as the most suitable records of possible long-term changes. Compared with previous climatologies, this study reveals a surface temperature rise (up to 2 °C), a clear deep dissolved oxygen minimum in the South Adriatic Gyre and a bottom summer oxygen minimum in the North Adriatic. Below 100 m all properties profoundly differ between the Middle and the South Adriatic. The South Adriatic Pit clearly shows the remote effects of the Eastern Mediterranean Transient, while no effect is observed in Middle Adriatic Pits. The deepest part of the South Adriatic seems now to be significantly saltier (+0.18 since the period 1911–1914, with an increase of +0.018 decade−1 since the late 1940s) and warmer (+0.54 °C since 1911–1914), even though a long-term temperature trend could not be statistically demonstrated. Conversely, the Middle Adriatic Pits present a long-term increase in apparent oxygen utilisation (+0.77 mL L−1 since 1911–1914, with a constant increase of +0.2 mL L−1 decade−1 after the 1970s).


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