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With increasing demand for biobased materials, major importance was given to the extraction and application of polysaccharides issued from renewable biomasses like algae. In this work, we investigate the feasibility of elaborating an active ulvan-based biomembrane prepared from stranded Ulva sp. biomass. Variations of extraction parameters showed that the optimal yield (13.8% w/w) was obtained using methanol under Soxhlet extraction for the defatting step and 5% (w/v) of ammonium oxalate as chelating reagent. The molecular weight (MW) was determined by gel permeation chromatography (GPC), which showed variability of MW from 201 to 1841 kDa depending on the extraction procedure. The monosaccharide composition of the obtained high MW ulvan showed the presence of rhamnose (17.61 ± 0.5%), xylose (9.22 ± 0.56%), and glucuronic acid (24.86 ± 1.29%). Purity and quality of ulvan were also assessed by FTIR and TGA analyses. The high MW ulvan fraction was thereafter used for the synthesis of a polyelectrolyte-type ulvan/chitosan biomembrane at low KCl concentration. The obtained membrane was then characterized using FTIR and XPS analyses, which evidenced that the ulvan sulfur groups were implicated in the interaction with chitosan chains. Finally, to assess the biological properties of the biomembrane, anticoagulant behavior was evaluated using APTT assay, and it has been found to significantly increase the blood clotting time in comparison with controls. This work shows the proof of concept of ulvan conversion to high added value products and, therefore, consolidates the implementation of cost-effective biorefinery approaches of green macroalgal biomass.
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ORIGINAL ARTICLE
Efficient extraction of a high molecular weight ulvan from stranded
Ulva sp. biomass: application on the active biomembrane synthesis
Cyrine Ben Amor
1
&Mohamed Amine Jmel
1
&Pascale Chevallier
2
&Diego Mantovani
2
&Issam Smaali
1
Received: 22 December 2020 /Revised: 22 February 2021 /Accepted: 5 March 2021
#Springer-Verlag GmbH Germany, part of Springer Nature 2021
Abstract
With increasing demand for biobased materials, major importance was given to the extraction and application of polysaccharides
issued from renewable biomasses like algae. In this work, we investigate the feasibility of elaborating an active ulvan-based
biomembrane prepared from stranded Ulva sp. biomass. Variations of extraction parameters showed that the optimal yield
(13.8% w/w) was obtained using methanol under Soxhlet extraction for the defatting step and 5% (w/v) of ammonium oxalate
as chelating reagent. The molecular weight (MW) was determined by gel permeation chromatography (GPC), which showed
variability of MW from 201 to 1841 kDa depending on the extraction procedure. The monosaccharide composition of the
obtained high MW ulvan showed the presence of rhamnose (17.61 ± 0.5%), xylose (9.22 ± 0.56%), and glucuronic acid
(24.86 ± 1.29%). Purity and quality of ulvan were also assessed by FTIR and TGA analyses. The high MW ulvan fraction
was thereafter used for the synthesis of a polyelectrolyte-type ulvan/chitosan biomembrane at low KCl concentration. The
obtained membrane was then characterized using FTIR and XPS analyses, which evidenced that the ulvan sulfur groups were
implicated in the interaction with chitosan chains. Finally, to assess the biological properties of the biomembrane, anticoagulant
behavior was evaluated using APTT assay, and it has been found to significantly increase the blood clotting time in comparison
with controls. This work shows the proof of concept of ulvan conversion to high added value products and, therefore, consol-
idates the implementation of cost-effective biorefinery approaches of green macroalgal biomass.
Keywords Macroalgal biomass .Ulvan .Extraction .Active biomembrane .Anticoagulant
1 Introduction
In the last decade, research on biomass valorization gained
interest. In fact, natural biopolymers exhibit structural diver-
sities and various functionalities, making them attractive for
many application fields. Among these biopolymers, polysac-
charides are of particular interest thanks to their physical, rhe-
ological, and chemical properties, being also recognized for
their potential biological applications. The list of known nat-
ural polysaccharides continues to grow, thanks to new discov-
eries in animal and plant materials. Many recent works have
focused on marine plants because they represent an important
source of complex and original polysaccharides [1]. Among
the promising marine biomasses, green macroalgae represent
an abundant renewable and under-valued biomass with nu-
merous interesting properties [2].
Macroalgae offer several advantages compared to tradi-
tional terrestrial raw materials, notably higher productivity
(biomass produced per unit area), no competition with arable
lands, and lower consumption of freshwater [3,4]. These main
advantages make algal biomass an important starting material
for various industrial applications [5]. Green algae (especially
Ulvales) in fact represent the most important available bio-
mass which proliferates mainly in coastal waters, and are fre-
quently involved in the proliferation of algal blooms in coastal
and lagoon waters in the form of tides[6,7]. So far, this
biomass causes environmental problems and has very little
*Issam Smaali
issam.smaali@insat.rnu.tn
1
INSAT, Laboratory of Protein Engineering and Bioactive Molecules,
University of Carthage, BP 676, Centre Urbain Nord,
1080 Tunis, Cedex, Tunisia
2
Laboratory for Biomaterials and Bioengineering, Canada Research
Chair I in Biomaterials and Bioengineering for the Innovation in
Surgery, Department of Min-Met-Materials Engineering, Research
Center of CHU de Quebec, Division of Regenerative Medicine,
University Laval, QC, Quebec G1V 0A6, Canada
https://doi.org/10.1007/s13399-021-01426-9
/ Published online: 12 March 2021
Biomass Conversion and Biorefinery (2023) 13:3975–3985
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... This high heterogeneity in the ulvan size and the influence of the extraction method has been described in the literature. Other parameters influencing the molecular weight of ulvan include the source, species, extraction conditions, degree of sulfation and ramification, monosaccharide composition, etc. Amor et al. [32] reported Mw for ulvan extracted from Ulva sp. ranging from 201.1 to 1841 kDa depending on the extraction method and time, concluding that grinding and maceration lead to smaller ulvan fractions compared to Soxhlet extraction. ...
... The importance of the molecular weight distribution is due to its direct link with ulvan physicochemical properties and biological activities and, therefore, on the biopolymer This high heterogeneity in the ulvan size and the influence of the extraction method has been described in the literature. Other parameters influencing the molecular weight of ulvan include the source, species, extraction conditions, degree of sulfation and ramification, monosaccharide composition, etc. Amor et al. [32] reported M w for ulvan extracted from Ulva sp. ranging from 201.1 to 1841 kDa depending on the extraction method and time, concluding that grinding and maceration lead to smaller ulvan fractions compared to Soxhlet extraction. ...
... This indicates more homogeneous ulvan fractions with similar molecular weights. This homogeneity could contribute to the mechanical properties and stability of the films since a homogeneous molecular weight distribution is more likely to form stable films since the interactions between the polymer chains are more predictable and lead to a more uniform structure [32]. ...
Article
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Ulvan is a sulfated polysaccharide extracted from green macroalgae with unique structural and compositional properties. Due to its biocompatibility, biodegradability, and film-forming properties, as well as high stability, ulvan has shown promising potential as an ingredient of biopolymer films such as sustainable and readily biodegradable biomaterials that could replace petroleum-based plastics in diverse applications such as packaging. This work investigates the potential of Ulva fenestrata as a source of ulvan. Enzyme-assisted extraction with commercial cellulases (Viscozyme L and Cellulysin) and proteases (Neutrase 0.8L and Flavourzyme) was used for cell wall disruption, and the effect of the extraction time (3, 6, 17, and 20 h) on the ulvan yield and its main characteristics (molecular weight, functional groups, purity, and antioxidant capacity) were investigated. Furthermore, a combined process based on enzymatic and ultrasound extraction was performed. Results showed that higher extraction times led to higher ulvan yields, reaching a maximum of 14.1% dw with Cellulysin after 20 h. The combination of enzymatic and ultrasound-assisted extraction resulted in the highest ulvan extraction (17.9% dw). The relatively high protein content in U. fenestrata (19.8% dw) makes the residual biomass, after ulvan extraction, a potential protein source in food and feed applications.
... The assistance of microwaves facilitated a rapid and efficient process, achieving a deacetylation degree (DD) of 75% (commercial chitosan) to 95% (Supplementary File). Microwave heating directly interacts with the molecules in the reaction mixture, leading to a rapid temperature increase, reducing deacetylation time, and conserving energy [27,28]. Moreover, an increase in DD correlated with an enhancement in the antimicrobial activity of chitosan by contributing to a higher quantity of protonated amine groups interacting with the negative components of bacterial cellular membranes [28,29]. ...
... Microwave heating directly interacts with the molecules in the reaction mixture, leading to a rapid temperature increase, reducing deacetylation time, and conserving energy [27,28]. Moreover, an increase in DD correlated with an enhancement in the antimicrobial activity of chitosan by contributing to a higher quantity of protonated amine groups interacting with the negative components of bacterial cellular membranes [28,29]. Furthermore, with a higher positive charge density on the chitosan backbone, smaller-sized nano systems can be obtained through ionic gelation [30]. ...
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The natural evolution of microorganisms, as well as the inappropriate use of medicines, have accelerated the problem of drug resistance to many of the antibiotics employed today. Colistin, a lipopeptide antibiotic used as a last resort against multi-resistant strains, has also begun to present these challenges. Therefore, this study was focused on establishing whether colistin associated with chitosan nanoparticles could improve its antibiotic activity on an extremely resistant clinical isolate of Pseudomonas aeruginosa, which is a clinically relevant Gram-negative bacterium. For this aim, nanoparticulate systems based on phytic acid cross-linked chitosan and loaded with colistin were prepared by the ionic gelation method. The characterization included particle size, polydispersity index-PDI, and zeta potential measurements, as well as thermal (DSC) and spectrophotometric (FTIR) analysis. Encapsulation efficiency was assessed by the bicinchoninic acid (BCA) method, while the antimicrobial evaluation was made following the CLSI guidelines. The results showed that colistin-loaded nanoparticles were monodispersed (PDI = 0.196) with a particle size of around 266 nm and a positive zeta potential (+33.5 mV), and were able to associate with around 65.8% of colistin and decrease the minimum inhibitory concentration from 16 μg/mL to 4 μg/mL. These results suggest that the association of antibiotics with nanostructured systems could be an interesting alternative to recover the antimicrobial activity on resistant strains.
... The extraction parameters, such as time, temperature, and biomass-to-solvent ratio, have been investigated to optimize the extraction yield and antioxidant activity of ulvan (Ning et al., 2022). Ulvan has also been used to synthesize an ulvan/chitosan biomembrane with potential applications in the biomedical field (Ben Amor et al., 2023). ...
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Ulva sp., a green macroalgae known as sea lettuce, is rich in polysaccharides, proteins, minerals, and bioactive compounds with antimutagenic, anticoagulant, anticancer, anti-inflammatory, antibacterial, and nutraceutical properties. Its abundance along the Aegean Sea coast poses an environmental challenge, as it is often disposed of as waste. However, Ulva sp. holds potential for high-value products in cosmetics and dietary supplements. Optimizing the extraction of its bioactive compounds using response surface methodology involved adjusting ethanol concentration, solid/liquid ratio, and extraction time. Key responses evaluated included yield, total polysaccharides, total protein, total phenol, total antioxidant activity, alpha-glucosidase inhibitory activity, and yeast cell glucose uptake. In this study, extraction yields ranged from 0.86% to 22.47% based on variations in extraction conditions. The highest total protein content was 106.88 mg BSA/g dry extract, while the polysaccharide content was determined to be 15.42%. The highest values for total phenol content and antioxidant capacity were found to be 82.15 mg GAE/g dry extract and 63.63 mg Trolox/g dry extract, respectively. The determination of the total amounts of antioxidants and phenolic compounds in extracts may expand their potential applications. In addition, the potential application of Ulva sp extracts as inhibitors for the treatment of diabetes has been demonstrated through experiments assessing both alpha-glucosidase enzyme inhibition and glucose uptake in yeast cells. The results support an environmentally friendly approach for the utilization of Ulva sp. from waste into valuable antidiabetic products.
... 12 In addition, chemical components of Ulva sp. have been used to synthesize edible films, 13 pharmaceuticals, 14 and biomembranes. 15 Therefore, efficient exploitation of Ulva sp. contributes to sustainable biochemical production from carbon dioxide. ...
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... Hence, it is essential to explore research that can integrate transformation processes to convert olive waste into high value-added products, more effectively. This will help to alter the olive oil production's linear economy into a more circular economy [21][22][23]. Thus, a cost-effective and greener treatment process step that manage huge quantities at an industrial scale is required for the valorization of this biomass in order to lower its resistance to bioconversion. ...
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... Ulvan can be extracted in several different ways including acid extraction, combined enzymatic and chemical extraction (Yaich et al., 2017) and Soxhlet extraction (Ben Amor et al., 2021). Acid extraction is particularly cost-effective and eco-friendly as citric acid can be utilized (Manikandan & Lens, 2022a, 2022b. ...
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