Guluronic acid content as a factor affecting turbidity removal potential of alginate

Moral, Cigdem Kivilcimdan
Ertesvag, Helga
Sanin, Faika Dilek
Alginates are natural polymers composed of mannuronic and guluronic acid residues. They are currently extracted from brown algae; however, alginate can also be synthesized by some species of Azotobacter and Pseudomonas. Alginates with different proportion of mannuronic and guluronic acids are known to have different characteristics and form gels at different extents in the presence of calcium ions. The aim of this work was to investigate the usefulness of alginate as a non-toxic coagulant used in purification of drinking water. This study utilized alginates from Azotobacter vinelandii having different guluronic acid levels. These were obtained partly by changing the cultivation parameters, partly by epimerizing a purified alginate sample in vitro using the A. vinelandii mannuronan C-5 epimerase AlgE1. The different alginates were then used for coagulation together with calcium. The results showed that turbidity removal capability was dependent on the content of guluronic acid residues. For the best performing samples, the turbidity decreased from 10 NTU to 1 NTU by the use of only 2 mg/L of alginate and 1.5 mM of calcium chloride.


Manganese(III) acetate-mediated oxidative coupling of phenylhydrazines with benzene: a novel method for biaryl coupling
Demir, Ayhan Sıtkı; Reis, O; Ozgul-Karaaslan, E (2001-01-01)
The reaction of phenylhydrazines with benzene in the presence of manganese(III) acetate affords biaryls in good yields. The same reaction was carried out with similar oxidants, such as Co-III, Ce-IV and Pb-IV; among these oxidants Mn-III acetate shows higher efficiency and selectivity.
Potassium permanganate/carboxylic acid/organic solvent: a powerful reagent for enone oxidation and aryl coupling reactions
Demir, Ayhan Gürbüz (2008-06-30)
The alpha'-acetoxylation of enones and the alpha-acetoxylation of aromatic ketones were carried out with potassium permanganate and acetic acid, in which acetoxylation products were obtained in 74-96% yields. The same reaction was carried out with carboxylic acids other than acetic acid, which furnished corresponding acyloxy ketones with the same regioselectivity. For the first time, formyloxylation products were synthesized in a 61-85% yield by using formic acid. The potassium permanganate and acetic acid ...
Effect of sucrose concentration on monomer distribution of alginate
Moral, Cigdem Kivilcimdan; Doğan, Özdemir; Sanin, Faika Dilek (2012-09-23)
Alginate is a natural biopolymer composed of mannuronic and guluronic acids. In this study, alginate was produced by Azotobacter vinelandii ATCC® 9046 in a laboratory fermenter under controlled conditions. Effect of variation of sucrose concentration on alginate quality and quantity was investigated. It appeared that 20 g/L of sucrose concentration was the optimum dose for alginate production with maximum alginate concentration of 4.5 g/L. Similarly, a higher degree of polymerization seemed to be achieved a...
Benzaldehyde Lyase-Catalyzed Direct Amidation of Aldehydes with Nitroso Compounds
Ayhan, Peruze; Demir, Ayhan Sıtkı (Wiley, 2011-03-07)
Benzaldehyde lyase from the Pseudomonas fluorescens catalyzes the reaction of aromatic aldehydes with nitroso compounds and furnishes N-arylhydroxamic acids in high yields. Aromatic aldehydes and benzoins are converted into enamine-carbanion-like intermediates prior to their reaction with nitroso compounds. The kinetic resolution of rac-2-hydroxy-1,2-diphenylethanones furnished (S)-benzoins and arylhydroxamic acids with high enantioselectivities and conversions.
An investigation of agitation speed as a factor affecting the quantity and monomer distribution of alginate from Azotobacter vinelandii ATCC(A (R)) 9046
Moral, C. Kivilcimdan; Sanin, Faika Dilek (2012-03-01)
Alginate is a copolymer of beta-d-mannuronic and alpha-l-guluronic acids. Distribution of these monomers in the alginate structure is one of the important characteristics that affect the commercial value of the polymer. In the present work, the effect of agitation speed in the range of 200-700 rpm on alginate production by Azotobacter vinelandii ATCC(A (R)) 9046 was investigated at a dissolved oxygen tension of 5% of air saturation. Experiments were conducted in a fermentor operated in batch mode for 72 h w...
Citation Formats
C. K. Moral, H. Ertesvag, and F. D. Sanin, “Guluronic acid content as a factor affecting turbidity removal potential of alginate,” ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH, pp. 22568–22576, 2016, Accessed: 00, 2020. [Online]. Available: