scholarly journals Oil and alginate content in Hydroclathrus clathratus of the st. martin’s Island, Bangladesh

2018 ◽  
Vol 3 (5) ◽  
Author(s):  
Rashedul Alam Chowdhury M
Keyword(s):  
Alginate Content ◽  
Hydroclathrus Clathratus

scholarly journals In vitro biological activity of Hydroclathrus clathratus and its use as an extracellular bioreductant for silver nanoparticle formation

2020 ◽  
Vol 9 (1) ◽  
pp. 416-428 ◽  
Author(s):  
Raghad R. Alzahrani ◽  
Manal M. Alkhulaifi ◽  
Nouf M. Al-Enazi
Keyword(s):  
Biological Activity ◽  
Unsaturated Fatty Acids ◽  
Multidrug Resistant ◽  
Chemical Components ◽  
Resistant Bacteria ◽  
Transmission Electron ◽  
Hydroclathrus Clathratus ◽  
Adaptive Nature ◽  
First Time

AbstractThe adaptive nature of algae results in producing unique chemical components that are gaining attention due to their efficiency in many fields and abundance. In this study, we screened the phytochemicals from the brown alga Hydroclathrus clathratus and tested its ability to produce silver nanoparticles (AgNPs) extracellularly for the first time. Lastly, we investigated its biological activity against a variety of bacteria. The biosynthesized nanoparticles were characterized by UV-visible spectroscopy, Fourier-transform infrared spectroscopy, dynamic light scattering, transmission electron microscopy, and energy-dispersive spectroscopy. The biological efficacy of AgNPs was tested against eighteen different bacteria, including seven multidrug-resistant bacteria. Phytochemical screening of the alga revealed the presence of saturated and unsaturated fatty acids, sugars, carboxylic acid derivatives, triterpenoids, steroids, and other components. Formed AgNPs were stable and ranged in size between 7 and 83 nm and presented a variety of shapes. Acinetobacter baumannii, Staphylococcus aureus, Methicillin-resistant S. aureus (MRSA), and MDR A. baumannii were the most affected among the bacteria. The biofilm formation and development assay presented a noteworthy activity against MRSA, with an inhibition percentage of 99%. Acknowledging the future of nano-antibiotics encourages scientists to explore and enhance their potency, notably if they were obtained using green, rapid, and efficient methods.

Method for the Quantification of Alginate in Microcapsules

1993 ◽  
Vol 2 (5) ◽  
pp. 429-436 ◽  
Author(s):  
Jean-Pierre Hallé ◽  
Danielle Landry ◽  
Alain Fournier ◽  
Michèle Beaudry ◽  
Francois A. Leblond
Keyword(s):  
Methylene Blue ◽  
Alkaline Medium ◽  
High Sensitivity ◽  
Sodium Concentration ◽  
The Other ◽  
Sensitive Assay ◽  
Reliable Measurement ◽  
Alginate Concentration ◽  
Other Substances ◽  
Alginate Content

Alginate is a key reagent in the preparation of microcapsules for cell transplantation. To address the question of the intracapsular alginate concentration, a sensitive assay has been developed to quantify the alginate content of microcapsules. The method is based on the metachromatic change induced by alginate binding to the dye, 1,9-dimethyl methylene blue (DMMB). The assay has a high sensitivity and precision. It covers a wide concentration range enabling the measurement of alginate in dilute supernatants as well as in microcapsules. For the latter, the membrane is initially dissolved by incubating the microcapsules in an alkaline medium. The effect of potentially interfering substances (poly-l-lysine (PLL), citrate, chloride, sodium) and of pH has been studied. Poly-l-lysine interfered with the assay at pH 6.5 but not at pH 13. Interference by sodium augmented with increasing sodium concentration and reached a plateau at 200 mM. This problem was overcome by routinely adjusting all samples to 500 mM sodium. The other substances tested had a negligible effect on the assay. The reliable measurement of alginate with this new assay will allow the optimization of the intracapsular alginate concentration.

scholarly journals Taxonomic reassessment of the Indo-Pacific Scytosiphonaceae (Phaeophyceae): Hydroclathrus rapanuii sp. nov. and Chnoospora minima from Easter Island, with proposal of Dactylosiphon gen. nov. and Pseudochnoospora gen. nov.

2018 ◽  
Vol 61 (1) ◽  
pp. 47-64 ◽  
Author(s):  
Wilfred John E. Santiañez ◽  
Erasmo C. Macaya ◽  
Kyung Min Lee ◽  
Ga Youn Cho ◽  
Sung Min Boo ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Phylogenetic Analyses ◽  
Easter Island ◽  
New Genera ◽  
Monotypic Genus ◽  
Southeastern Pacific ◽  
Molecular Phylogenetic ◽  
Thin Membranes ◽  
Hydroclathrus Clathratus ◽  
Molecular Phylogenetic Data

AbstractA new and putatively endemic species ofHydroclathrus,Hydroclathrus rapanuii, is described from the geographically isolated Easter Island in the southeastern Pacific based on morphological and molecular phylogenetic data. It is distinguished from otherHydroclathrusby thalli of unevenly furrowed thin membranes, and angular, block-like plurangial sori. Our phylogenetic analyses indicated thatH. rapanuiiis closely related to the generitypeHydroclathrus clathratus. We also report on the morphology and phylogeny ofChnoospora minimafrom Easter I. and elsewhere in the Indo-Pacific Ocean, noting the previously unreported presence of hollow portions in its medulla. Although not collected from Easter I., we herein propose the recognition of two new genera,Dactylosiphongen. nov. andPseudochnoosporagen. nov., based on our three-gene phylogeny and their known morphologies and anatomies.Dactylosiphonis based on the three species currently assigned toColpomenia(C. bullosa,C. durvillei, andC. wynnei) that are genetically and morphologically (i.e. thalli with erect and finger-like tubes arising from a common saccate base) distinct from other members ofColpomenia. The monotypic genusPseudochnoosporais represented by the decumbent, branching, and inter-adhesive species currently known asChnoospora implexa. With the above proposals, we further increase the genus-level diversity of Scytosiphonaceae in the Indo-Pacific Ocean.

Synthesis of spherical porous cross-linked glutaraldehyde/poly(vinyl alcohol) hydrogels

2016 ◽  
Vol 36 (9) ◽  
pp. 891-898
Author(s):  
Sadao Araki ◽  
Yuko Shirakura ◽  
Harufumi Suzuki ◽  
Hideki Yamamoto
Keyword(s):  
Sodium Alginate ◽  
Vinyl Alcohol ◽  
Calcium Alginate ◽  
Chloride Solution ◽  
Calcium Chloride Solution ◽  
Inorganic Salts ◽  
Poly Vinyl Alcohol ◽  
Cross Linking ◽  
Alginate Content ◽  
Calcium Alginate Gels

Abstract Spherical glutaraldehyde cross-linked poly(vinyl alcohol) (PVA) hydrogels (G-PVA) were prepared in three steps: gelatification, cross-linking, and removal of alginate. Gelatification was carried out by dropping a solution of alginate, PVA, and glutaraldehyde into a calcium chloride solution to form calcium alginate. Calcium alginate gels were prepared at 20°C, 40°C, 60°C, and 80°C to study the effect of gelatification temperature on the formation of pores on the surface of G-PVA. The effect of the alginate content was studied. PVA and glutaraldehyde were cross-linked by immersion of the gels in a solution of H2SO4 and Na2SO4. The effect of sodium alginate and inorganic salts, such as MgSO4 and K2SO4, on the formation of pores on the surface of G-PVA was confirmed.

Preparation of Macroporous Hydroxyapatite/Chitosan-Alginate Composite Scaffolds for Bone Implants

2007 ◽  
Vol 342-343 ◽  
pp. 217-220 ◽  
Author(s):  
Hyeong Ho Jin ◽  
Hyang Mi Lee ◽  
Ik Min Park ◽  
Hong Chae Park ◽  
Seog Young Yoon
Keyword(s):  
Pore Structure ◽  
Pore Diameter ◽  
Precipitation Method ◽  
Bone Implants ◽  
Composite Scaffolds ◽  
Uniform Microstructure ◽  
Alginate Content ◽  
Co Precipitation

Porous HAp/chitosan-alginate composite scaffolds were successfully synthesized by insitu co-precipitation method. During the preparation of HAp/chitosan-alginate composite scaffolds, the interaction between chitosan-alginate molecules would be reduced with increasing HAp content, with the resulting that the chitosan-alginate molecules were homogeneously dispersed in the composite scaffolds. The chitosan-alginate content was found to be almost consistent as initially added during the preparation. These results imply that chitosan-alginate was almost perfectly incorporated into the composites. It was found that the pore structure of the composite scaffolds with low HAp content was similar to chitosan-alginate scaffolds, and the morphology of uniform microstructure was unaffected by the presence of HAp. However, the pore diameter decreased with increasing the HAp content up to HAp content of 30 wt%, eventually the pore structure was collapsed and the composites scaffolds appeared to be agglomerated at higher HAp content.

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