Agar Industry Research Articles

Pyrolysis of macroalgae residue from the agar industry for silica‐rich biochar and other sustainable chemicals: Process performances, product applications, and simple business scenario

AbstractThe macroalgae residue from the industrial agar extraction process contains a significant amount of carbon and has potential as a renewable feedstock. Unfortunately, it is often overlooked and is poorly utilized. This study aims to valorize this macroalgae residue through pyrolysis to produce silica‐rich biochar and other value‐added products in the form of biocrude oil (BCO) and biopyrolysis gas. The macroalgae residue was pyrolyzed at 300–700 °C with a heating rate of 20–40 °C/min. Yields of biochar, BCO, and gas of 62%, 25%, and 13% were obtained at a temperature of 700 °C and a heating rate of 20 °C/min. Biochar has a porous structure, a surface area exceeding 15 m2/g, and is dominated by amorphous silica of up to 13%. This silica‐rich biochar also contains Na and K, which hold potential benefits in agriculture, serving as soil ameliorants and playing a crucial role in enhancing soil fertility and promoting plant growth. In the meantime, BCO contains 29.3% carboxylic acid group as the most important chemical component. Other than that, the biopyrolysis gas contains mainly CH4 and H2 (up to 24–32%), which can act as chemical building blocks. Finally, a simple business scenario of silica‐rich biochar production reveals that it has a specific cost of 0.37 US$/kg. It could be economically viable as a soil ameliorant or fertilizer. However, challenges persist in scaling up production to an industrial scale.

Co-cultures from Plants and Cyanobacteria: A New Way for Production Systems in Agriculture and Bioprocess Engineering.

Due to the global increase in the world population, it is not possible to ensure a sufficient food supply without additional nitrogen input into the soil. About 30-50% of agricultural yields are due to the use of chemical fertilizers in modern times. However, overfertilization threatens biodiversity, such as nitrogen-loving, fast-growing species overgrow others. The production of artificial fertilizers produces nitrogen oxides, which act as greenhouse gases. In addition, overfertilization of fields also releases ammonia, which damages surface waters through acidification and eutrophication. Diazotrophic cyanobacteria, which usually form a natural, stable biofilm, can fix nitrogen from the atmosphere and release it into the environment. Thus, they could provide an alternative to artificial fertilizers. In addition to this, biofilms stabilize soils and thus protect against soil erosion and desiccation. This chapter deals with the potential of cyanobacteria as the use of natural fertilizer is described. Possible partners such as plants and callus cells and the advantages of artificial co-cultivation will be discussed later. In addition, different cultivation systems for studying artificial co-cultures will be presented. Finally, the potential of artificial co-cultures in the agar industry will be discussed.

Alginate hydrogel incorporating cellulose nanofiber from solid waste agar industry for hydrophobic antibiotic delivery: Synthesis and characterization

Undoubtedly, there is an increasing inclination towards the development of hydrogels derived from natural sources for the purpose of delivering hydrophobic antibiotics. In this study, alginate hydrogels containing cellulose nanofibrils (CNF) were synthesized from solid waste agar industry (SWAI) via Hydrated deep eutectic solvent (DES) hydrolysis and mechanical treatment, intending to encapsulate chloramphenicol and examine the properties of the alginate-CNF (ALG-CNF) hydrogel at various CNF concentrations. The CNF displays a fibrous morphology, surface charge of − 39.3 ± 0.3 mV, 62.95% crystallinity, and type-I cellulose. The incorporation of CNF notably affected the characteristics of the ALG-CNF hydrogel. Chloramphenicol was effectively encapsulated within the ALG-CNF hydrogel matrix. Chloramphenicol release showed a biphasic profile, with controlled release occurring within 48 h. The drug release kinetics adhered to the Korsmeyer-Peppas model, reflecting pseudo-Fickian diffusion (n < 0.45), with a high determination coefficient (R² ≈ 0.95). Antibacterial susceptibility tests demonstrated that ALG-CNF hydrogels inhibited the growth of E. coli, S. aureus, and P. aeruginosa. The ALG-CNF hydrogel demonstrated favorable physical properties, drug release, and antibacterial properties, making it a prospective candidate for future studies on wound dressings and hydrophobic drug delivery systems.

The Invasive Seaweed Agarophyton vermiculophyllum from Oualidia Lagoon (Northwestern Moroccan Atlantic Coast) as a Source of Agar: Yield, Chemical Characteristics, and Rheological Properties

Agar is a hydrophilic biopolymer extracted from red seaweed. This phycocolloid consists of two components: agarose and agaropectin. In the present work, agar extracted from the invasive red seaweed Agarophyton vermiculophyllum was characterized using physical, chemical, and spectroscopic analyses to investigate the effect of alkaline pretreatment on agar properties. Two extraction conditions, native and alkali-pretreated agars, were comparatively studied. The native yield (28.4 ± 0.9%) was higher than that of the alkaline-pretreated agar (20.4 ± 0.8%). The alkali-pretreated agar showed higher gel strength (763.8 ± 57.0g cm−2), gelling (36.5 ± 0.9 °C), and melting (83.2 ± 0.6 °C) temperatures and increased 3,6-anhydrogalactose (26.2 ± 1.9%) and decreased sulfate contents (6.2 ± 0.8%) compared with native agar (gel strength: 204.8 ± 17.10g cm−2, gelling temperature: 29.5 ± 0.9 °C, melting temperature: 73.4 ± 0.7 °C, 3,6-AG content: 13.8 ± 0.7%, sulfate content: 10.5 ± 0.5%). The alkaline pretreatment improved the agar’s gelling properties and significantly influenced its chemical properties. In view of the obtained results, A. vermiculophyllum might potentially be thought of as a viable source for the agar industry in Morocco, serving as a local source of agar.

Sustainable lithium-ion battery separators based on cellulose and soy protein membranes

The food industry produces millions of tons of natural by-products. Through this study, we followed an environmentally friendly strategy using discards, such as soy protein isolate (SPI) from soya oil production and marine cellulose (Cell) from the agar industry, in order to achieve added-value applications. In particular, this work focuses on the development of membranes based on soy protein and cellulose, and their validation as battery separator membranes toward sustainable energy storage systems. SPI membranes with Cell show excellent compatibility with the electrolyte based on physical interactions. These physical interactions favor the swelling of the membranes, reaching swelling values of 1000% after three days in the liquid electrolyte. The membranes are thermally stable up to 180 °C. After being subjected to the liquid electrolyte, it is observed that the microstructure of the membranes change, but the porous structure is maintained, while the materials remain easy to handle. The ionic conductivity value, lithium transference number and battery performance in cathodic half-cells are ∼ 5.8 mS.cm−1, 0.77, and 112 mAh.g−1 at 1C-rate, respectively. Overall, considering environmental issues and circular economy, it is proven that it is possible to obtain more sustainable high-performance lithium-ion batteries based on waste materials.

Bioethanol production from seaweed solid waste biomass of agar processing

This paper describes about the potential application of renewable energy sources from biomass (seaweed waste) to replace fossil fuels combustion which produced CO2 emission and heavy metal pollution. The objective of the research is to utilize the seaweed solid waste from agar production industry for bioethanol feedstock. The enzymatic method was carried out for glucose production with the addition 1% of surfactant Tween 20 during the saccharification process of three kinds of substrate concentration (20, 25, 30% dw) and 10 FPU/g substrate for the cellulose concentration and used S. cerevisae as yeast in the fermentation process for bioethanol production. The result showed that the highest reducing sugar value (122.4 mg/mL) and 2.86% for the bioethanol content were from 30% dw treatment of substrate concentration of solid agar waste. Therefore, the waste from agar industry is a potential raw material to be used as biofuel and could reduce the heavy metal problems.

Spectroscopic Characterization and Gel Properties of Agar from Two Gelidium Species from the Atlantic Coast of Morocco

The commercial value of agar in the phycocolloid market depends mostly on the agar yield and quality. The present study investigates the agar content and characterization of two Gelidiales Gelidium corneum and Gelidium microdon from the Moroccan Atlantic coast. Spectroscopic and rheological characterization of extracted agar without and with alkali pretreatments were evaluated. The highest agar yield was detected for mild alkaline pretreatment (N2CO3). The native agar content in G. corneum was 16.21%, while those pretreated with NaOH and N2CO3 ranged from 6.2 to 20.50 %. The agar yields of G. microdon showed values of 12.23%, 14.87%, and 17.73%, corresponding respectively to native agar, NaOH, and Na2CO3 pretreatments. Agar with alkali pretreatments depicted the better gelling property with higher gel strength and elevated gelling and melting temperatures. 13C NMR spectroscopy showed that G. Corneum has a typical unsubstituted and weakly methylated agar pattern. However, G. microdon revealed the presence of methyl and sulfate groups at the C4 of 4-O-L-galactose residues, responsible for the low gelling ability of the native agar. The decline of sulfate groups after alkali pretreatments were proved by FTIR spectroscopy. This study demonstrates that G. microdon produces a quality of agar similar to that of G. corneum. Thus G. microdon could be regarded as a potential additional source of agar industry in Morocco.

Agar extraction and purification of R-phycoerythrin from Gracilaria tenuistipitata, and subsequent wastewater treatment by Ulva prolifera

This study investigated the large-scale use of the red macroalga Gracilaria tenuistipitata to extract partially purified R-phycoerythrin in combination with the sequential extraction of agar. The main objective was to investigate the purification of R-PE, the extraction of agar and treatment of wastewater from the whole extraction process using the green macroalga Ulva prolifera. Results showed that the processing of 1 kg fresh biomass of G. tenuistipitata yielded a 30.34 μg/g R-phycoerythrin (purification ratio > 4) with 13.83% extraction efficiency. Initial phycobiliprotein extraction had no effect on the agar yield. The physicochemical properties of the agar had industrial applications. This method of extraction reduced the water volume and alkali requirement compared with that from direct extraction from algae. In addition, the removal rates (mean ± standard deviation) from wastewater of BOD, COD, total nitrogen, inorganic nitrogen, ammonia nitrogen, nitrate, nitrite, total phosphorus and inorganic phosphorus were 28.34 ± 0.10%, 23.50 ± 3.47%, 45.59 ± 6.31%, 63.82 ± 2.94%, 40.77 ± 0.95%, 74.06 ± 5.63%, 70.37 ± 2.59%, 65.26 ± 5.77%, and 72.40 ± 5.43% after the treatment with 2 days respectively. This extraction and subsequently eco-friendly wastewater treatment method could have practical application in the agar industry.

A sustainable process for the recovery of volatile constituents from Gracilaria lemaneiformis in agar production and evaluation of their antioxidant activities

BackgroundGracilaria lemaneiformis is a common red alga used as a raw material source for the agar industry. Its extract is rich in natural volatile constituents (VCs) having antioxidant activities. Herein, a sustainable method was used to recover VCs from the alga. The chemical composition of VCs present in the n-hexane fraction was analyzed by gas chromatography–mass spectroscopy (GC–MS) and the antioxidant potential was measured using a series of in vitro biochemical assays, including DPPH, hydroxyl, and superoxide radical scavenging assays.ResultsThe recovery yield of the VCs was 0.823 wt% of the dry mass of G. lemaneiformis. A total of 25 VCs were successfully identified, comprising approximately 99.94% of the total volume. The major component was n-hexadecanoic acid (38.57%), followed by oleic acid (25.48%), arachidonic acid (12.84%), and tetradecanoic acid (2.52%). In addition, The VCs displayed strong free radical scavenging activity in the DPPH (IC50 = 21.56 mg/L), hydroxyl (IC50 = 18.34 mg/L), and superoxide (IC50 = 391.12 mg/L) radical scavenging assays. The antioxidant activities of the VCs exhibited a dose-dependence at concentrations ranging from 5 to 200 mg/L.ConclusionThe results indicated that the sustainable process improved the agar quality and that the extract contained many natural VCs with antioxidant activities, which have the potential to be used in functional food and cosmetics instead of as a discarded byproduct of the agar industry.

Hydrochars from industrial macroalgae “Gelidium Sesquipedale” biomass wastes

Macroalgae wastes from the Agar–Agar industry were used as a feedstock to obtain hydrochars by means of hydrothermal carbonization. The effect of temperature (200 °C and 230 °C) and time (2 h and 6 h) on the yield, higher heating value (HHV) and chemical-morphological-textural properties of the hydrochars was studied. The carbon content and the higher heating value were observed to increase with the hydrothermal carbonization. The hydrochars yields (up to 60%) were much higher than yields obtained using conventional char (27.5–33.5%). The hydrochar obtained at 230 °C and after 6 h showed a HHV of 23.25 MJ/kg, which is similar to that of lignite HHV. The H/C and O/C atomic ratios decreased as a consequence of the dehydration and decarboxilation reactions. Hydrothermal carbonization barely changed the vegetal structure of the macroalgae waste. The hydrochars were found to be essentially meso-macroporous with average pore sizes of up to 110.5 nm.

Global shortage of technical agars: back to basics (resource management)

Bacteriological and technical agars are in short supply with potential consequences for research, public health, and clinical labs around the world. To diagnose bottlenecks and sustainability problems that may be putting the industry at risk, we analyzed the available time series for the global landings of Gelidium, the most important raw materials for the industry. Data on the harvest of Gelidium spp. have been reported since1912, when Japan was the only producer. After World War II the diversification of harvested species and producing countries resulted in a strong increase in global landings. Maximum harvest yields of almost 60,000 t year−1 in the 1960s were sustained until the 1980s, after which landings decreased continuously to the present. In the 2010s, a reduction in the global production to about 25,000 t year−1 was observed, which was lower than the yields of the 1950s. Landings by important producers such as Japan, Korea, Spain, and Portugal have collapsed. This is the ultimate cause of the present shortage of bacteriological and technical agars. However, an important factor at play is the concentration of the global landings of Gelidium in Morocco, as its relative contribution increased from 23% in the 1960s to the present 82%. Two specific bottlenecks were identified: restrictive export quotas of unprocessed Gelidium in favor of the national agar industry and resource management regulations that were apparently not enforced resulting in over-harvesting and resource decline. The global industry may well be dependent on resource management basics. Simple harvest statistics must be gathered such as the harvest effort and the variation of harvest yields along the harvest season. We discuss how this information is fundamental to manage the resource. The available harvest statistics are generally poor and limited and vary significantly among different sources of data. Probable confusions between dry and wet weight reporting and poor discrimination of the species harvested need to be resolved.

Optimization of decolorization process in agar production from Gracilaria lemaneiformis and evaluation of antioxidant activities of the extract rich in natural pigments.

Gracilaria lemaneiformis is mainly used as a raw material source for agar industry, and its extract is rich in natural pigments with antioxidant activities. In this study, a solvent reflux extraction method for decolorization of G. lemaneiformis has been developed in agar production. The extraction conditions were optimized as follows: solvent-to-material ratio, 50:1; ethanol concentration, 70%; number of extractions, 3; extraction time, 0.5h, under which the total antioxidant yield of the extract reached 2.89±0.88mg/g dried seaweeds. Their IC50 values of DPPH radical scavenging activity, hydroxyl radical scavenging activity and superoxide anion scavenging activity were 21.91±1.8mg/L, 40.59±1.5mg/L and 160.87±2.8mg/L, respectively. Further isolation and spectroscopic analysis of natural pigments suggested the strong antioxidant capacities were attributed to chlorophyll derivatives. The results indicate that the decolorization process was able to improve the agar quality, and the extract containing lots of natural pigments had antioxidant activities which may be used in functional food and cosmetics.

Genetic and morphological analyses of Gracilaria firma and G. changii (Gracilariaceae, Rhodophyta), the commercially important agarophytes in western Pacific.

Many studies classifying Gracilaria species for the exploitation of agarophytes and the development of the agar industry were conducted before the prevalence of molecular tools, resulting in the description of many species based solely on their morphology. Gracilaria firma and G. changii are among the commercially important agarophytes from the western Pacific; both feature branches with basal constrictions that taper toward acute apices. In this study, we contrasted the morpho-anatomical circumscriptions of the two traditionally described species with molecular data from samples that included representatives of G. changii collected from its type locality. Concerted molecular analyses using the rbcL and cox1 gene sequences, coupled with morphological observations of the collections from the western Pacific, revealed no inherent differences to support the treatment of the two entities as distinct taxa. We propose merging G. changii (a later synonym) into G. firma and recognize G. firma based on thallus branches with abrupt basal constrictions that gradually taper toward acute (or sometimes broken) apices, cystocarps consisting of small gonimoblast cells and inconspicuous multinucleate tubular nutritive cells issuing from gonimoblasts extending into the inner pericarp at the cystocarp floor, as well as deep spermatangial conceptacles of the verrucosa-type. The validation of specimens under different names as a single genetic species is useful to allow communication and knowledge transfer among groups from different fields. This study also revealed considerably low number of haplotypes and nucleotide diversity with apparent phylogeographic patterns for G. firma in the region. Populations from the Philippines and Taiwan were divergent from each other as well as from the populations from Malaysia, Thailand, Singapore and Vietnam. Establishment of baseline data on the genetic diversity of this commercially important agarophyte is relevant in the context of cultivation, as limited genetic diversity may jeopardize the potential for its genetic improvement over time.

Enzymatic saccharification of agar waste from Gracilaria verrucosa and Gelidium latifolium for bioethanol production

Worldwide, 9600 t of agar is produced annually. Meanwhile, 60% of the waste produced from the agar industry yearly do not get treated. Our present study aims to study the enzymatic saccharification of solid agar waste produced from two of the most widely used agarophytes in the agar industry, Gracilaria verrucosa and Gelidium latifolium. Gracilaria species are the most common raw material in the food grade agar industry, while Gelidium species are the most common raw material used for bacteriological and pharmaceutical purposes because of the high-quality agar that is produced from these species. Our results showed that waste generated from agar extraction still contained sugars which could be optimized by acid pretreatment and enzymatic saccharification. Gracilaria verrucosa resulted in a higher agar yield (35.15 ± 1.17%), but produced less agar waste (20.91 ± 0.43%) than G. latifolium. After sequential acid pretreatment and enzymatic saccharification of the agar waste, the agar waste hydrolysate of G. latifolium resulted in higher glucose, galactose, and ethanol production, and a higher ethanol yield (18.17 ± 0.75, 16.17 ± 2.07, and 10.83 ± 0.30 g L−1 and 0.33 g g−1, respectively) than G. verrucosa. The results from our present study may be used to optimize biorefinery utilization of G. verrucosa and G. latifolium.

Agar properties of Gracilaria species (Gracilariaceae, Rhodophyta) collected from different natural habitats in Malaysia

The yield and quality of agar from Gracilaria species collected from distinct natural habitats (mangrove swamp, rocky shore, sandy mudflat) along the west coast of Peninsular Malaysia were evaluated in this study. The agar content was found to be significantly higher in G. changii and G. edulis growing in the mangrove swamp, while the lowest agar content was recorded for G. changii and G. edulis collected from the sandy mudflat. Higher agar gel strength was obtained from the three Gracilaria species collected from the mangrove swamp compared to those that live in the sandy mudflat and rocky shore. The intraspecific variations found in gelling temperature were well correlated with the trend of changes in agar gel strength, except for G. changii collected from the sandy mudflat and rocky shore. The intraspecific and interspecific variations of agar melting temperature did not show a consistent trend for all Gracilaria species tested. The agars of Gracilaria spp. collected from the rocky shore showed a significantly higher gel syneresis while the lowest gel syneresis was recorded for the agars of samples collected from the mangrove swamp, except for the agars of G. salicornia from different habitats which showed no difference. In conclusion, the mangrove swamp is a natural habitat which produces Gracilaria with good agar properties, in terms of agar yield, gel strength and gel hysteresis, thus it can be considered as a potential site for seaweed farming and mariculture for the agar industry in Malaysia.

Effects of CO2 levels and light intensities on growth and amino acid contents in red seaweed Gracilaria lemaneiformis

The seaweed Gracilaria lemaneiformis is largely maricultivated in China, for use as food and as a material in the agar industry. This alga experiences ocean acidification caused by rising atmospheric CO2 levels, and experiences changing light levels caused by self-shading during the later period of mariculture. In this study, growth and amino acid (AA) content responses of G. lemaneiformis to different CO2 levels (the present and the predicted increased levels) and varying light levels at 28 (±1)°C temperature conditions were investigated. The results showed that a higher light level enhanced algal growth and decreased water loss, but reduced AA accumulation. Decreased pH levels (as a result of CO2 elevation) also enhanced algal growth and reduced AA contents, but the decreases in the AA score at the lower pH levels were not significant under the two light level treatments. In this study, the light treatments had greater influences on growth and AA contents than CO2 levels. The results suggest that G. lemaneiformis quality will be negatively affected during the later mariculture production period as levels of CO2 rise and global temperatures increase.

Biodiversity of Cellulolytic Bacteria Isolated from the Solid Wastes of Agar Seaweed Processing Industry

Agar is polysaccharide extracted from the seaweed Gracilaria sp. It is commonly used for food, medical, pharmaceutical and biotechnology industries. The red seaweed Gracilaria verrucosa is the most common material used for the extraction of agar, processed into sheet and powder. A total of 7169 tons solid waste is produced from the agar industry in Indonesia which can further result in 4301.4 tons per year of cellulose. However, solid wastes from agar seaweed processing industry have not been managed and used optimally, and therefore seaweed solid wastes can be used as one of alternative source of cellulose and cellulolytic bacteria. In this research, we reported the isolation of cellulose-producing bacteria from seaweed processing industry wastes using specific media 1 % LIA (Limbah Industri Agar, waste of seaweed processing industry). Sequencing and subsequent phylogenetic analysis of the 16S rRNA genes amplified from the obtained 7 isolates identified them as Serratia marcescens, Chryseobacterium indovlogenes, Bacillus pumilus, Bacillus cereus, Strenatrophomonas maltophila, and Pseudomonas aeruginosa.

Injection-manufactured biocomposites from extruded soy protein with algae waste as a filler

Many studies have been carried out with proteins using casting and compression techniques to manufacture composites; however, the commercial feasibility of protein-based biocomposites is highly associated with the employment of industrial processing techniques, such as extrusion and injection moulding, actually used for synthetic composites. In this work, those processing methods were successfully employed to develop soy protein biocomposites with good barrier and mechanical properties. Furthermore, a natural waste from the agar–agar industry, which showed good compatibility with soy protein, was used as a filler, contributing to the development of more sustainable composites.

An orthogonal design to optimize seed production, out-planting, and cultivation of the industrially overexploited red alga Gracilaria edulis (Rhodophyta)

Marine algal resources are of significant importance due to their renewable nature and plentiful availability; however, they also are subjected to indiscriminate harvesting. Despite multi-organizational efforts under the Bay of Bengal Program implemented by the Food and Agriculture Organization (FAO) of the United Nations, the Indian agar industry still heavily relies on the natural harvest of Gracilaria edulis from the southeastern coast of the Gulf of Mannar. Experimental cultivation of this species has been successful, but lack of a year-round supply of quality seed material has hampered the prospects of undertaking commercial farming. To maximize the efficiency of artificial seedling production, we used a Taguchi orthogonal array design to determine the optimal temperature, salinity, and pH for seedling production from primary, secondary, and tertiary fragments. The maximum growth was obtained at 25 °C, 20 ppt salinity, and pH 7.5, where the highest daily growth rate (DGR) of 4.88 ± 1.04 % day−1 (K 3 = 3.194) was recorded in tertiary fragments. The DGR of seedlings grown with shaking as well as static cultures ranged from 8.33 ± 1.50 to 10.26 ± 0.01 % day−1 after 10 days. Analysis of variance (ANOVA) showed that water motion did not significantly affect growth. The out-planting was successful for seedlings derived from laboratory culture. Among the two harvesting methods examined, namely complete and clipping harvest, the former resulted in the highest biomass yield (7.21 ± 0.83 kg fresh wt m−2) and DGR (5.93 ± 0.11 % day−1). A statistically significant difference (F = 16.976; p < 0.001 and F = 3.359; p < 0.02) was observed for yield and DGR, respectively, between the methods. It is thus imperative to augment the algal stock for year-round mariculture thereby negating the consequences of overexploitation.

Assessment of alternative sources of seaweed polysaccharides in Argentina: potentials of the agarophyte Gelidium crinale (Hare ex Turner) Gaillon (Rhodophyta, Gelidiales)

The phycocolloids industry in Argentina has been based on the importation of non-native species and the exploitation of natural populations of Gracilaria, which are currently declining. This study was carried out to evaluate the potential of Gelidium crinale as an unexploited source of agar in this country. The yield and composition of polysaccharides extracted from G. crinale, as well as the growth potential of this species were studied. In vitro cultures of apical sections were carried out; relative growth rates (RGR) and data were analyzed through repeated measurements. Explants rapidly duplicated their initial size, producing numerous proliferations and achieving structural complexity. RGR of explants, primary proliferations, and secondary proliferations were high and similar. Polysaccharide extraction was done under three conditions: acid pre-extraction treatment + pressure boiled (AP), water pre-extraction treatment + pressure boiled (WP), and water pre-extraction treatment + boiled (WB). Polysaccharides were characterized through infrared spectroscopy, X-ray fluorescence, thermogravimetric, and elemental analysis. Polysaccharides obtained corresponded to the agar-type, and showed high similarity to commercial agar samples, with low sulfate and methyl contents. Higher yields were obtained with pressure extractions; however, acid treatment did not increase the amount of extracted biopolymers. Their degradation occurred in the range 250–400 °C. Polysaccharides obtained under AP conditions had a degradation curve similar to food-grade agar-agar, whereas degradation curves of polysaccharides obtained without acid treatment were similar to biotechnology-grade agar-agar. According to the results, G. crinale from Anegada Bay produces a high-quality agar to be considered for the Argentinean agar industry; however, micropropagation techniques would be indispensable to increase its bioavailability.