Alginate Yield Research Articles

Making of Alginate Dental Impression Material from Sargassum duplicatum

This study was aimed to prepare dental impression material from Sargassum duplicatum taken from Binuangeun, Banten. The setting time was tested according to ANSI/ADA Specification for Alginate Impression Materials 1983. After extraction, obtained the alginate powder then mixed its water/powder ratio from the combination of alginate composition and tested final setting time. Variations of the formulations used different calcium sulfate (0,1 g; 0,2 g; and 0,3 g). Product quality parameters are lumps, solubility, consistency, flow, tearing, setting time. The alginate yield obtained from Sargassum duplicatum by 31 % with characteristic gel strength by 816 (gr/cm2); viscosity 238 mPas (2%; room temperature). The highest ratio is the best ratio by adding calcium sulfate powder of 0.1 gram with a setting time of 3 minutes.

Effect of Extraction Time and Na2CO3 Concentration on The Characteristics of Alginate Extracted from Sargassum sp.

Alginate is a polysaccharide extracted from cell walls and intracellular matrix of brown seaweed, and has been widely used for industrial purpose due to gelling capabilities in the presence of divalent cations. However, the characteristics of alginate extracted are depend on alginate gel strength and viscosity. The objective of this research was to investigate the effect of extraction time and Na2CO3 concentration on the characteristics of alginates extracted from Sargassum sp. by acid method. Alginate extractions were conducted by varying the extraction time for 1.5, 2.0 and 2.5 hours; and varying the Na2CO3 concentration of 1, 2 and 3 %. The characteristics observed are alginate yield, viscosity, pH, and water content. The alginates extracted using various Na2CO3 concentration and extraction time resulted alginates with low, medium and high viscosity. Furthermore, the yield, pH and water content of alginates extracted in this research had fulfilled the standard of Food Chemical Codex.

Seasonal biomass and alginate stock assessment of three abundant genera of brown macroalgae using multispectral high resolution satellite remote sensing: A case study at Ekas Bay (Lombok, Indonesia)

The potential of Indonesian bays as alginate producers was assessed by determining the stock of wild brown algae and exploring their biomass as alginophytes at the scale of entire bay, using a combination of field observations, remote sensing high resolution data and GIS tools. Ekas Bay in Lombok Island presented a stock of brown macroalgae which varied with season and species: for Padina the biomass reached 97.85±12.63 and 79.54±2.53tons in May/June and November respectively; for Sargassaceae species, it reached 669.70±109.64 and 147.70±77.97tons in May/June and November respectively. The best alginate yields occurred during the May/June period: Padina could produce 9.10±0.06tons DW of alginates. Interestingly, Sargassum/Turbinaria together allow 207.61±0.42tons DW of alginates. This study suggests that wild Sargassaceae represent an interesting stock in terms of biomass, alginate yield and M/G ratio.

Development of Alginate Extraction Method from Seaweed Turbinaria ornata

Indonesia has a lot of high potential seaweed as a source of an alginate, but the extraction method had been used was not suitable. The aim of this research is to develop alginate extraction method from Turbinaria ornata seaweed with calcium method and compare the cost of extraction with an acid method as a control. In this research, various concentration of calcium chloride (CaCl2) was used in the separation of alginate from the extracted filtrate. The concentration of CaCl2 used varies from 0.50; 0.75; 1.00; 1.25; and 1.50 M. For comparison, alginate extraction with acid (control) method was used. Alginate quality parameters observed included alginate yield, product color degree, and gel viscosity. The results showed that the yield of alginate produced by calcium method was 36.89; 44.00; 56.00; 52.89 and 53.11% and for control 22.45%. From the degree of product color, CaCl2 concentration did not significantly affect the color of alginate but was darker when compared to the product extracted by the acid method. The viscosity of alginate produced by calcium method was 27,69; 26,57; 24.50; 22.41 and 19.92 cP while for control 32.88 cP. The extraction of Na-alginate with calcium method can decrease the need for Na-alginate extraction cost by 85% from the amount of Na-alginate extraction cost requirement by the acid method.

Bimonthly variation in the chemical composition and biological activity of the brown seaweed Eisenia arborea (Laminariales: Ochrophyta) from Bahía Magdalena, Baja California Sur, Mexico

The aim of this study was to describe the bimonthly variation in the proximate chemical composition, alginate, and fucoidan yield and ethanolic extract content, including the anticoagulant and antioxidant activity of the extracts and quality tests of alginates, from blades and stipes of Eisenia arborea collected in Bahia Magdalena, Baja California Sur, Mexico. Significant differences were found in the chemical composition between months and also between the alga structures. The major constituents in both blades (53.8%) and stipes (47.6%) were carbohydrates and ash (28.4 and 33.9%, respectively). The crude ethanolic extract yield and the antioxidant activity in blades were higher than in stipes throughout the period with a maximum in September (5.4% and EC50 = 82.7 μg mL−1). The highest yield of crude fucoidan was obtained in September (20%) for blades and March (8.7%) for stipes. The anticoagulant activity of fucoidan was higher in January for blades and May for stipes. The alginate yield showed significant difference (p > 0.05) between blades and stipes. The highest yield for blades was obtained in November (21.3%) and for stipes in January (24.5%). Our results suggest that the best period to harvest the alga is from September to March, considering the higher yields and better properties of the extracts.

Characterizing the Three Different Alginate Type of Sargassum siliquosum

This research was aimed to identify the brown seaweed, to characterize the acid, sodium and calcium alginate, and to examine the alginate yield. The identification was done phaenotypically. The extraction method was pretreated by ethanol depigmentation, followed by the extraction of Na2CO3/EDTA and CaCl2 and presipitated with absolute ethanol. The characterization of alginate was done by FT-IR spectroscopy and Thin Layer Chromatography by comparing the samples with standard alginate (Sigma, USA). The key of identification showed that the species was Sargassum siliquosum. There are similarities in signal vibration and TLC spots among the samples and the standard. The TLC test was also showed that those alginates contain mannuronic and guluronic acid. The highest yield was produced by Sodium alginate (40,34% + 0,21), followed by Acid alginate (11,51% + 0,15) and Calcium alginate (4,8% + 0,09). Keywords: alginate, characterization, Sargassum siliquosum, yield

Tối ưu hóa quá trình nấu chiết alginate từ bã rong nâu Turbinaria ornata (Turner) J. AGARDH

Alginate is liner polysaccharides extracted from brown seaweed. It is a co-polymer composed of (1® 4)-β-D-mannuronic acid and α-L-guluronic acid. In this paper, the effects of technological factors such as pH value of sodium carbonate solution, temperature and time during the alkaline extraction step on alginate yield and viscosity of the alginate were studied. The results showed that the best conditions for alkaline extraction alginate from brown seaweed residue Turbinaria ornata were determined at pH value of sodium carbonate solution 11, temperature 59oC for 1.5 hours. The maximum alginate content and viscosity were 32.15% dry weight algae and 743 mPa.s, respectively.

Optimization of alginate alkaline extraction technology from Sargassum latifolium and its potential antioxidant and emulsifying properties

Alginate was recovered from Sargassum latifolium biomass using different conditions of alkali treatment. Box-Behnken experimental design was evaluated to study the influence of alkali:alga ratio, temperature and time on alginate yield, and its molecular weight (MW) and mannuronic/guluronic acid ratio (M/G). The second-order polynomial equations were analyzed by appropriate statistical methods. Extraction temperature and time were the most important factors during alginate alkaline extraction. MW and M/G ratio played an important role in controlling the reducing power of alginate. Increasing pH of the alginate solutions enhanced its reducing capacity, while thermal treatment showed a negative effect. Additionally, alginate exhibited good emulsion stabilizing capacities with diverse hydrophobic compounds. Emulsifying activity was less sensitive to temperature, ionic strength and more stable at acidic pH.

Analysis of respiratory activity and carbon usage of a mutant of Azotobacter vinelandii impaired in poly-β-hydroxybutyrate synthesis.

In this study, the respiratory activity and carbon usage of the mutant strain of A. vinelandii AT6, impaired in poly-β-hydroxybutyrate (PHB) production, and their relationship with the synthesis of alginate were evaluated. The alginate yield and the specific oxygen uptake rate were higher (2.5-fold and 62%, respectively) for the AT6 strain, compared to the control strain (ATCC 9046), both in shake flasks cultures and in bioreactor, under fixed dissolved oxygen tension (1%). In contrast, the degree of acetylation was similar in both strains. These results, together with the analysis of carbon usage (% C-mol), suggest that in the case of the AT6 strain, the flux of acetyl-CoA (precursor molecule for PHB biosynthesis and alginate acetylation) was diverted to the respiratory chain passing through the tricarboxylic acids cycle, and an important % C-mol was directed through alginate biosynthesis, up to 25.9% and to a lesser extent, to biomass production (19.7%).

Abundance, Biomass and Alginate Yield of Padina australis in Sumbawa Aquatic

Padina australis is one of brown seaweed which mostly found in Sumbawa coastal area. This seaweed has a potential as a raw material for alginate. We examined abundance, biomass and alginate content of P. australis. Data were collected monthly from October 2012 to January 2013. Sampling was located in the aquatic of Sumbawa Regency by the number of stations is 3 stations. Station 1 was located in the aquatic of Labuhan Badas District, stations 2 and 3 were in the aquatic of Bungin Island. The highest value of biomass were found on May in station 1 (33.98 g wet weight/m2) and the lowest values on station2 (3.12 g wet weight/m2). Alginate content showed the highest value of 6.65% on May in station 1 and the lowest value of 3.08% on July in station 2. The results showed that biomass and alginate contents of P. australis significantly influenced by interaction of physical and chemical enviromental factors. P. australis grew in station 1 on May had the highest biomass and alginate contents with characteristics of physical and chemical enviromental were hard substrate, current 0.40 m s-1, pH 8, temperature 32°C and salinity 32 psu.

Extraction of alginate from Sargassum muticum: process optimization and study of its functional activities

In the present study, alginate extraction from the brown seaweed Sargassum muticum was studied using single factor analysis. Response Surface Methodology-Central Composite Rotatary design (RSM-CCRD) was performed to reduce and optimize extraction temperature, alkali concentration, and consumption of solvent. Different interaction effect of three extraction factors of temperature (60–100 °C), alkali (1–5 %), and aqueous ethanol (70–100 %) were studied to reduce residual waste. The result showed that the optimum extraction yield (13.57 %) was obtained with 86 °C temperature, 3 % alkali, and 93 % ethanol. A second order polynomial equation using multiple regression analysis was developed, and the predicted extraction yield showed a high coefficient of determination (R 2 = 0.98) with the experimental alginate yield. The functionality of extracted alginate and residual supernatant left over after extraction were evaluated for total polyphenols and its antioxidant capacity. The extracted alginate was further characterized using fluorescence spectrophotometer and nuclear magnetic resonance spectroscopy. The 1H NMR data revealed that extracted alginate has an M/G ratio of 1.08 and η < 1.

Effect of Extraction Methods on the Yield and Physiochemical Properties of Polysaccharides Extracted from Seaweed Available in Sri Lanka

Agar, carrageenan and alginate are high valued seaweed polysaccharides, which are used as gelation and thickening agents in different food, pharmaceutical and biotechnological industries. The annual global production of the polysaccharides has recently reached 100,000 tons with a gross market value just above US$ 1.1 billion. In Sri Lanka although several seaweed species are available, there is no systematic study on comparison of method of extraction, yield and physicochemical properties of polysaccharides from seaweeds. Seaweed species Gracilaria edulis, Gracilaria verrucosa, Kapphaphycus alverazi and Sargussum wightti were collected from North and South coast of Sri Lanka. Gracilaria edulis and Gracilaria verrucosa were used for agar extraction with acid and alkaline treatments. Carrageenan was extracted from Kapphaphycus alvarezii using alkaline treatments. Three types of carrageenan (kappa, iota, lambda) were separated using freeze thawing, jelly pressing and alcohol precipitation methods respectively. For the extraction of alginates from Sargussum wightti samples were treated with acid and alkaline and hot and cold extraction methods were used. Some of the above physiochemical properties were compared with commercial available products. In agar yield (16.6%) of acid treated Gracilaria eduliswas high when compared to Gracilaria verrucosa. The gel strength was high in alkaline treatments (429 g.cm2) and was obtained from G. verrucosa. Freeze thawed method gave the highest yield (23.4%) and gel strength 715 g/cm2 in kappa carrageenan extracts. The highest alginate yield (35%) was obtained from Sargussum wightti in hot extraction treatments. The mean viscosity of agar and carrageenan purchased from commercially and extracted polysaccharides didn’t show significant difference. When considered the proximate composition mean crude protein contents of extracted and commercial products were not significantly difference on dry weight basis among agar, carrageenan and alginates. The mean value of iodine content of extracted and commercial product obtain from agar carrageenan and alginates were range from 32-58; 26-45 and 43-57 mg/l respectively. The mean sodium content of agar, carrageenan and alginates were significant difference between extracted polysaccharides and commercial product. There is also significant difference in the calcium contents of agar, carrageenan and alginates respectively. Chemical properties of agar carrageenan and alginates extracted in laboratory were more superior when compared to those properties of the products collected from the local market, but physical properties were at comparable levels. Considering the above extracted product can be promoted for commercial market.

The production, molecular weight and viscosifying power of alginate produced by Azotobacter vinelandii is affected by the carbon source in submerged cultures

Alginate is a linear polymer composed of &lt;span style="font-family: symbol;"&gt;b&lt;/span&gt;-1,4 linked mannuronic acid and its epimer, &lt;span style="font-family: symbol;"&gt;a&lt;/span&gt;-L-guluronic acid, and frequently extracted from marine algae, as from bacteria such as Azotobacter and Pseudomonas. Here, we show the impact of conventional and unconventional carbon sources on A. vinelandii growth, alginate production, its mean molecular weight (MMW) and its viscosifying power. Starting with 20 g/L of sugars, the highest biomass concentration was obtained using deproteinized and hydrolyzed whey (6.67±0.72 g/L), and sugarcane juice (6.68±0.45 g/L). However, the maximum alginate production was achieved using sucrose (5.11±0.37 g/L), as well the highest alginate yield and specific productivity. Otherwise, the higher alginate MMW was obtained using sugarcane juice (1203±120 kDa), and the higher viscosifying power was obtained using deproteinized/ hydrolyzed whey (23.8±2.6 cps L/galg). This information suggests that it is possible to manipulate the productivity and molecular characteristics of alginates, as a function of the carbon source used. All this, together with the knowledge of the effects of environmental conditions will allow for high yields of high added value biopolymers.

Phenology and alginates of two Sargassum species from the Caribbean coast of Colombia

The genus Sargassum (Phaeophyceae) forms large beds on rocky shores of the Colombian Caribbean, showing large seasonal fluctuations in biomass that are related to upwelling events in the area. This study describes the phenology of two benthic species of Sargassum from the Caribbean coast of Colombia, and presents a preliminary assessment of the alginate concentration and properties of viscosity and gel strength to determine their potential as an exploitable resource. Samples were collected during 2007 in the Santa Marta area. The first species was identified at genus level as Sargassum sp. The highest values of biomass and abundance of receptacles were recorded in April and the lowest between June and February. The other species was Sargassum cymosum. It showed higher biomass and persisted a longer time than Sargassum sp. In spite of this, the biomass and reproductive period of both species were markedly seasonal and low during most of the year. Alginate yield was relatively high in both species, compared to that reported for other Sargassum species. The viscosity of the alginates was very low and may thus have only few applications in the industry; however, the gel strength of the alginates of both species was competitive, compared with other commercial algal products. This study suggests that while these two species of Sargassum in Colombia are potential candidates for the commercial production of alginates in regard to some applications, the marked seasonality of the species advises caution for a sustainable exploitation.

Biosorption Capacity for Cadmium of Brown Seaweed Sargassum sinicola and Sargassum lapazeanum in the Gulf of California

Brown algae Sargassum sinicola and Sargassum lapazeanum were tested as cadmium biosorbents in coastal environments close to natural and enriched areas of phosphorite ore. Differences in the concentration of cadmium in these brown algae were found, reflecting the bioavailability of the metal ion in seawater at several sites. In the laboratory, maximum biosorption capacity (q max) of cadmium by these nonliving algae was determined according to the Langmuir adsorption isotherm as 62.42 ± 0.44 mg g−1 with the affinity constant (b) of 0.09 and 71.20 ± 0.80 with b of 0.03 for S. sinicola and S. lapazeanum, respectively. Alginate yield was 19.16 ± 1.52% and 12.7 ± 1.31%, respectively. Although S. sinicola had far lower biosorption capacity than S. lapazeanum, the affinity for cadmium for S. sinicola makes this alga more suitable as a biosorbent because of its high q max and large biomass on the eastern coast of the Baja California Peninsula. Sargassum biomass was estimated at 180,000 t, with S. sinicola contributing to over 70%.

BANCOS DE Sargassum cymosum (PHAEOPHYCEAE) NA ENSEADA DE ARMAÇÃO DO ITAPOCOROY, PENHA, SC: BIOMASSA E RENDIMENTO EM ALGINATO

The seaweed Sargassum occurs in large beds along Brazilian Coast, mainly in Southern and Southeastern areas. This seaweed is very important to local fauna and flora. It is also economically important mainly due alginate to production. Several kinds of approaches are needed to planning its sustainable management. This work aims to evaluate the size of subtidal Sargassum cymosum beds in Armação do Itapocoroy Bay (Penha, SC), quantifying its spatial variations on biomass and associated seaweed community, and also evaluate alginate yield separately for vegetative and reproductive branches, for each bed. The Sargassum beds area in Armação do Itapocoroy Bay reached 14,137 m2. Total estimated biomass in the bay was 17.90 ± 9.07 ton wet mass. Mean biomass ranged from 142,64 (± 34,25) to 214,76 (±131,68) g dry mass m-2 between the beds. The alginate yield ranged from 18.63 to 25.00%, and reproductive branches yield was higher than vegetative branches yield. Reproductive structures alone yield about 30%. Despite many additional works are needed, these results indicate potential for Sargassum exploitation in Santa Catarina Coast.

The viscosifying power, degree of acetylation and molecular mass of the alginate produced by Azotobacter vinelandii in shake flasks are determined by the oxygen transfer rate

The objective of this study was to evaluate the influence of the specific power input and oxygen transfer rate (OTR) on changes in the alginate quality, in terms of the viscosifying power, molecular mass and degree of acetylation, of the polymer produced by Azotobacter vinelandii in shake flasks. Decreasing the shaking frequency from 200 to 100 rpm decreased the maximal volumetric power input ( P/ V) max from a maximal value of 1.5 kW m −3 to a minimal value of 0.23 kW m −3. As a result of the decrease in the maximal volumetric power input, the maximum oxygen transfer rate (OTR max) decreased from 6 mmol L −1 h −1 to 2.6 mmol L −1 h −1 and the RQ (respiratory quotient) increased from 0.95 to 1.21 for the lower and higher power input, respectively. A lower RQ value was associated with the highest conversion value of carbon source (sucrose) to alginate. In contrast, at lower OTR max values, culture broths with a higher viscosity were obtained. Thus, for the same alginate concentration (∼3.0 g L −1), the viscosity of cultures at an OTR max value of 2.26 mmol L −1 h −1 was twice as high with respect to the viscosity observed in the culture broth obtained at a higher power input (OTR max = 6.0 mmol L −1 h −1). In addition, under lower power input (lower OTR), the molecular mass and the degree of acetylation of the polymer were the highest. Additional experiments in a stirred bioreactor under constant DOT and agitation rate showed that under non-oxygen-limited conditions (5% of DOT), the alginate yield and the molecular mass of the polymer are determined by the OTR and are independent of the agitation rate of the culture.

Extraction and characterisation of alginate from brown seaweeds (Fucales, Phaeophyceae) collected from Port Dickson, Peninsular Malaysia

Four species of brown seaweeds, namely Sargassum baccularia, Sargassum binderi, Sargassum siliquosum and Turbinaria conoides, harvested from Port Dickson, Negeri Sembilan, Malaysia were analysed for ash content, alginate yield and alginate properties. Seaweeds calcined at 450°C were found to have low amount of non-combustible residue as these were not contaminated by calcareous animals. Alginate was extracted from these seaweeds by two methods: hot and cold. In the hot method, the storing time was 3 h and the processing temperature was 50°C, whilst in the cold method, the sample was stored overnight at room temperature. Higher yield of alginate was obtained by the hot method compared to the cold method, but alginate extracted by the cold method gave higher molecular weight. In the hot method, 49.9% of alginate was extracted from S. siliquosum, followed by T. conoides (41.4%), S. binderi (38.9%) and S. baccularia (26.7%). Alginate extracted from T. conoides has an average molecular weight, M w, of 8.06 × 105 g mol−1, whereas alginate from S. siliquosum was the lowest in M w (4.81 × 105 g mol−1) when the extraction was done at room temperature. Alginate extracted from S. baccularia was found to be very heat-sensitive. Its M w has dropped more than 83%, from 7.52 × 105 to 1.23 × 105 g mol−1, when the extraction temperature was raised. The effect of heat on the extent of depolymerisation of the alginate molecule of the other three brown seaweed species was less significant, with decrease in molecular weight ranging between 13% and 16%.

Seasonal variation on size and chemical constituents of Sargassum sinicola Setchell et Gardner from Bahía de La Paz, Baja California Sur, Mexico

SUMMARYInvestigation on seasonal variation in size and chemical constituents of Sargassum sinicola Setchell et Gardner from Bahía de La Paz, Baja California Sur, Mexico, was carried out from a control bed and compared with an experimental bed with artificial nutrients added. No significant differences were found between the control and experimental thalli for size or chemical composition, except for iodine and raw fiber. For control thalli the results were: size 7.5–56.0 cm, alginate yield 7.2–13.7%, viscosity 58.7–191.7 millipascal seconds (mPa s), mannitol 2.9–8.1%, raw fiber 5.5–7.5% and iodine 0.020–0.141%; while in the experimental thalli the size ranged from 7.5 to 80.3 cm and the alginate yield was 7.8–10.4%, viscosity 41.4–163.4 mPa s, mannitol 2.9–8.3%, raw fiber 5.9–10.7% and iodine 0.021–0.098%. These variations were related to its natural growth cycle, and showed reductions during the senescence period. Results suggest that S. sinicola is not affected by relatively low nutrient concentrations, and could be considered as raw material for alginate production.

Alginate, mannitol, phenolic compounds and biological activities of two range-extending brown algae, Sargassum mangarevense and Turbinaria ornata (Phaeophyta: Fucales), from Tahiti (French Polynesia)

This study deals with two range-extending brown algae from Tahitian coral reefs, Sargassum mangarevense and Turbinaria ornata; their alginate properties, mannitol and phenolic contents, antioxidant and antimicrobial activities were determined. Turbinaria ornata showed the richest alginate content with the highest extraction yield (19.2 ± 1.3% dw). Their alginates also exhibited the highest viscosity (50 ± 18 mPa.s), but the M:G ratios (mannuronic acid to glucuronic acid) of alginates (1.25–1.42) were similar in both species. Alginate yield displayed spatial variations, but no significant seasonal changes. The highest mannitol content was found in S. mangarevense (12.2 ± 2.1% dw) during the austral winter. With respect to other tropical Fucales, both algae exhibited also a high phenolic content (2.45–2.85% dw) with significant spatio-temporal variations. Furthermore, high antioxidant activity and activity against Staphylococcus aureus were also detected in extracts. According to these preliminary results, these two range-extending algae are of key interest in numerous industrial areas.