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The capacity of phosphorus (P) regeneration in water is a key factor influencing the outbreak of algal blooms. Phosphate-solubilizing bacteria (PSB) are the essential mediators of P cycling and may contribute to algal blooms. To explore the influence of inorganic phosphate-solubilizing bacteria (IPB) on sediment P release and the outbreak of ‘green tide’ Chaetomorpha linum, we conducted a simulation experiment using two dominant IPB strains isolated from the sediments of a macro-algal blooms contaminated Swan Lagoon, China. We analyzed the changes in P level in the overlying water, algal biomass, and P fractions in sediments under different inoculations of IPB strains. The results indicated that the inoculation of Bacillus sp. promoted sediment P release in Swan Lagoon. Chaetomorpha linum, the IPB strains, and the bacterial amount all significantly affected the total phosphorus (TP) concentration in water. However, under the treatments without C. linum, the TP concentration was much higher in the IPB1 (Bacillus flexus) group compared to the IPB2 (Bacillus megaterium) group, due to the strong adaptability of B. flexus strain to the external environment. The soluble reactive phosphorus (SRP) concentration in water in the treatments with algae was much lower than that of those without algae during the first 6 days. The biomass of C. linum was higher in both the inoculation groups than in the control group. However, the increase in algal biomass and P concentration in algal tissue were higher in the IPB1 than in the IPB2. These findings indicated that B. flexus had a greater effect on the sediment P release, promoting C. linum growth and accumulation of P in algae. Various P forms in sediments exhibited different releasing abilities, and the NH4Cl-P showed a high release potential during the inoculation. Meanwhile, the bacterial respiration resulted in a significant decline in dissolved oxygen level at the sediment–water interface that may have triggered redox-related P release. In most inoculation treatments without algae, the BD-P concentration in sediments declined under anoxic conditions. Our findings provide insight into the role of sediment P release through the action of PSB on the persistence of C. linum blooms in coastal waters. This information is important for developing effective nutrient management guidelines or controlling endogenous P pollution. [ABSTRACT FROM AUTHOR]

Utilizing plant-based resources, particularly their by-products, aligns with sustainability principles and circular bioeconomy, contributing to environmental preservation. The therapeutic potential of plant extracts is garnering increasing interest, and this study aimed to demonstrate promising outcomes from an extract obtained from an underutilized plant waste. Chaetomorpha linum, an invasive macroalga found in the Orbetello Lagoon, thrives in eutrophic conditions, forming persistent mats covering approximately 400 hectares since 2005. The biomass of C. linum undergoes mechanical harvesting and is treated as waste, requiring significant human efforts and economic resources—A critical concern for municipalities. Despite posing challenges to local ecosystems, the study identified C. linum as a natural source of bioactive metabolites. Phytochemical characterization revealed lipids, amino acids, and other compounds with potential anti-inflammatory activity in C. linum extract. In vitro assays with LPS-stimulated RAW 264.7 and TNF-α/IFN-γ-stimulated HaCaT cells showed the extract inhibited reactive oxygen species (ROS), nitric oxide (NO), and prostaglandin E2 (PGE2) productions, and reduced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expressions via NF-κB nuclear translocation, in RAW 264.7 cells. It also reduced chemokines (TARC/CCL17, RANTES/CCL5, MCP-1/CCL2, and IL-8) and the cytokine IL-1β production in HaCaT cells, suggesting potential as a therapeutic candidate for chronic diseases like atopic dermatitis. Finally, in silico studies indicated palmitic acid as a significant contributor to the observed effect. This research not only uncovered the untapped potential of C. linum but also laid the foundation for its integration into the circular bioeconomy, promoting sustainable practices, and innovative applications across various industries. [ABSTRACT FROM AUTHOR]

Background and Aim: Over the last decades, the poultry industry has experienced steady growth. Although the industry is gradually expanding in Indonesia, poultry feed production has always been expensive. There is a need to study alternative ingredients to obtain affordable feed from natural resources. Chaetomorpha linum (CL) is an abundant macroalgae available throughout the year in Indonesia. This study aimed to determine the effect of CL on the histological structure of the small intestine, pectoralis muscle, growth performance, and meat quality of broilers. Materials and Methods: This study used 300-day-old chick (DOC) male broilers that were reared until they were 21 days old. This study used a completely randomized design with four treatment groups and five replications, and each replication group contained 15 DOC individuals. The treatment groups consisted of Control (CON), CON basal feed (BF), CL1 (0.75%/kg BF), CL2 (1.5%/kg BF), and CL3 (3%/kg BF) groups. The histological structure of the small intestine, pectoralis muscle, growth performance, and meat quality of the broiler was examined. Results: Small intestine and pectoral muscle histomorphology, growth performance, and meat quality were significantly improved in the CL2 (1.5%) and CL3 (3%) groups compared with the CL1 (0.75%) and CON groups. Conclusion: Dietary CL supplementation ameliorates small intestine and pectoral muscle histomorphology, growth performance, and meat quality of broilers.

In this article, chemical structure and conformation in an aqueous solution of a new sulfated polysaccharide, PCL, extracted from green seaweed Chaetomorpha linum were elucidated by SEC-MALL, IR, NMR and SAXS. The results indicated that the obtained polysaccharide is a sulfated arabinogalactan with a molecular weight of 223 kDa, and is mainly composed of →3,6)-α-D-Galp4S→ and →2)-α-L-Araf→ connecting together through 1→3 glycoside linkages. It has a broken rod-like conformation in solution with Rgc estimated as 0.43 nm from SAXS measurements. The polysaccharide exhibited a notable anticoagulant activity measured by the assays of activated partial thromboplastintime, thrombintime and prothrombine time as well as a significant cytotoxic activity against hepatocellular, human breast cancer, and cervical cancer cell lines. [ABSTRACT FROM AUTHOR]

Background and Aim: Over the last decades, the poultry industry has experienced steady growth. Although the industry is gradually expanding in Indonesia, poultry feed production has always been expensive. There is a need to study alternative ingredients to obtain affordable feed from natural resources. Chaetomorpha linum (CL) is an abundant macroalgae available throughout the year in Indonesia. This study aimed to determine the effect of CL on the histological structure of the small intestine, pectoralis muscle, growth performance, and meat quality of broilers. Materials and Methods: This study used 300-day-old chick (DOC) male broilers that were reared until they were 21 days old. This study used a completely randomized design with four treatment groups and five replications, and each replication group contained 15 DOC individuals. The treatment groups consisted of Control (CON), CON basal feed (BF), CL1 (0.75%/kg BF), CL2 (1.5%/kg BF), and CL3 (3%/kg BF) groups. The histological structure of the small intestine, pectoralis muscle, growth performance, and meat quality of the broiler was examined. Results: Small intestine and pectoral muscle histomorphology, growth performance, and meat quality were significantly improved in the CL2 (1.5%) and CL3 (3%) groups compared with the CL1 (0.75%) and CON groups. Conclusion: Dietary CL supplementation ameliorates small intestine and pectoral muscle histomorphology, growth performance, and meat quality of broilers. [ABSTRACT FROM AUTHOR]

Utilizing plant-based resources, particularly their by-products, aligns with sustainability principles and circular bioeconomy, contributing to environmental preservation. The therapeutic potential of plant extracts is garnering increasing interest, and this study aimed to demonstrate promising outcomes from an extract obtained from an underutilized plant waste. Chaetomorpha linum, an invasive macroalga found in the Orbetello Lagoon, thrives in eutrophic conditions, forming persistent mats covering approximately 400 hectares since 2005. The biomass of C. linum undergoes mechanical harvesting and is treated as waste, requiring significant human efforts and economic resources—A critical concern for municipalities. Despite posing challenges to local ecosystems, the study identified C. linum as a natural source of bioactive metabolites. Phytochemical characterization revealed lipids, amino acids, and other compounds with potential anti-inflammatory activity in C. linum extract. In vitro assays with LPS-stimulated RAW 264.7 and TNF-α/IFN-γ-stimulated HaCaT cells showed the extract inhibited reactive oxygen species (ROS), nitric oxide (NO), and prostaglandin E2 (PGE2) productions, and reduced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expressions via NF-κB nuclear translocation, in RAW 264.7 cells. It also reduced chemokines (TARC/CCL17, RANTES/CCL5, MCP-1/CCL2, and IL-8) and the cytokine IL-1β production in HaCaT cells, suggesting potential as a therapeutic candidate for chronic diseases like atopic dermatitis. Finally, in silico studies indicated palmitic acid as a significant contributor to the observed effect. This research not only uncovered the untapped potential of C. linum but also laid the foundation for its integration into the circular bioeconomy, promoting sustainable practices, and innovative applications across various industries.

The study was used in the context of realigning novel low-cost materials for their better and improved optical properties. Emphasis was placed on the bio-nanocomposite approach for producing cellulose/starch/silver nanoparticle films. These polymeric films were produced using the solution casting technique followed by the thermal evaporation process. The structural model of the bio-composite films (CS:CL-CNC7:3–50%) was developed from our previous study. Subsequently, in order to improve the optical properties of bio-composite films, bio-nanocomposites were prepared by incorporating silver nanoparticles (AgNPs) ex situ at various concentrations (5–50% w/w). Characterization was conducted using UV-Visible (UV-Vis), Fourier Transform Infrared (FTIR), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) to understand the structure–property relationships. The FTIR analysis indicated a reduction in the number of waves associated with the OH functional groups by adding AgNPs due to the formation of new hydrogen bonds between the bio-composite matrix and the CL-WE-AgNPs. Based on mathematical equations, the optical bandgap energy, the energy of Urbach, the edge of absorption (Ed), and the carbon clusters (N) were estimated for CS:CL-CNC and CS:CL-CNC-AgNPs (5–50%) nanocomposite films. Furthermore, the optical bandgap values were shifted to the lower photon energy from 3.12 to 2.58 eV by increasing the AgNPs content, which indicates the semi-conductor effect on the composite system. The decrease in Urbach's energy is the result of a decrease in the disorder of the biopolymer matrix and/or attributed to an increase in crystalline size. In addition, the cluster carbon number increased from 121.56 to 177.75, respectively, from bio-composite to bio-nanocomposite with 50% AgNPs. This is due to the presence of a strong H-binding interaction between the bio-composite matrix and the AgNPs molecules. The results revealed that the incorporation of 20% AgNPs into the CS:CL-CNC7:3–50% bio-composite film could be the best candidate composition for all optical properties. It can be used for potential applications in the area of food packaging as well as successfully on opto-electronic devices. [ABSTRACT FROM AUTHOR]

In recent years, macroalgae and microalgae have played a significant role in the production of organic matter, fiber, and minerals on Earth. They contribute to both technical and medicinal applications as well as being a healthy and nutritious food for humans and animals. The theme of this work concerns the development and exploitation of Chaetomorpha linum (C. linum) biomass, through the elaboration of a new starch-based composite film reinforced by cellulose nanocrystals (CL-CNC) derived from C. linum. The first step involves the chemical extraction of CL-CNC from dry C. linum algae biomass. To achieve this, three types of cyclic treatment were adopted: alkalinization (sodium hydroxide) followed by bleaching (sodium hypochlorite) and acid hydrolysis (hydrochloric acid). We then studied the optimization of the development of bio-composite films based on corn starch (CS) reinforced by CL-CNC. These polymeric films were produced using the solution-casting technique followed by the thermal evaporation process. Structure and interactions were modified by using different amounts of glycerol plasticizers (20% and 50%) and different CS:CNC ratios (7:3 and 8:2). These materials were characterized by UV visible (UV/Vis), Fourier Transform Infrared (FTIR) and Scanning Electron Microscope (SEM) spectroscopy to understand structure-property relationships. The result revealed that the best matrix composition is 7:3 (CS: CL-CNC) with 50% glycerol, which reflects that the reinforcing effect of CL-CNC was greater in bio-composites prepared with a 50% plasticizer, revealing the formation of hydrogen bonds between CL-CNC and CS. [ABSTRACT FROM AUTHOR]

The current research focused on algae from the waters of the Black Sea—Chaetomorpha linum, Ulva intestinalis, Ericaria crinita, and bioreactors—Chlorella spp. and Arthrospira platensis/cyanobacterium/. Pigment content, total phenolic content, and antioxidant capacity were investigated for their use as pharmaceutical, food, and cosmetic ingredients. E. crinita exhibited the highest antioxidant activity by ORAC and HORAC (463.3 µmol TE/g and 463.3 µmol GAE/g) and the highest total content of polyphenols and rutin of the investigated algae. Lower protein content was found in saltwater algae than in freshwater algae. For the first time, biologically active substances from the Bulgarian A. platensis and Chlorella spp., produced in a bioreactor, have been quantitatively identified. A. platensis contained rutin (141.25 mg/100 g), naringenin (42.17 mg/100 g), quercetin (26.74 mg/100 g), kaempferol, and quercetin-3-β-glycoside. Phenolic acids were isolated: neochlorogenic (172.27 mg/100 g) for lyophilized and 5783 mg/100 g for convection-dried A. platensis. It has been found that the protein content in A. platensis (convection dried) and Chlorella spp. (lyophilized) was nearly 54% higher than that of green algae U. intestinalis from Varna. The lyophilization process reduced the protein content of A. platensis samples by almost 20%. The high protein content of convection-dried A. platensis (43.4%) and lyophilized Chlorella spp. (43.7%) identified them as suitable emulsifiers in colloidal and emulsion systems. [ABSTRACT FROM AUTHOR]

The study was used in the context of realigning novel low-cost materials for their better and improved optical properties. Emphasis was placed on the bio-nanocomposite approach for producing cellulose/starch/silver nanoparticle films. These polymeric films were produced using the solution casting technique followed by the thermal evaporation process. The structural model of the bio-composite films (CS:CL-CNC7:3–50%) was developed from our previous study. Subsequently, in order to improve the optical properties of bio-composite films, bio-nanocomposites were prepared by incorporating silver nanoparticles (AgNPs) ex situ at various concentrations (5–50% w/w). Characterization was conducted using UV-Visible (UV-Vis), Fourier Transform Infrared (FTIR), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) to understand the structure–property relationships. The FTIR analysis indicated a reduction in the number of waves associated with the OH functional groups by adding AgNPs due to the formation of new hydrogen bonds between the bio-composite matrix and the CL-WE-AgNPs. Based on mathematical equations, the optical bandgap energy, the energy of Urbach, the edge of absorption (Ed), and the carbon clusters (N) were estimated for CS:CL-CNC and CS:CL-CNC-AgNPs (5–50%) nanocomposite films. Furthermore, the optical bandgap values were shifted to the lower photon energy from 3.12 to 2.58 eV by increasing the AgNPs content, which indicates the semi-conductor effect on the composite system. The decrease in Urbach’s energy is the result of a decrease in the disorder of the biopolymer matrix and/or attributed to an increase in crystalline size. In addition, the cluster carbon number increased from 121.56 to 177.75, respectively, from bio-composite to bio-nanocomposite with 50% AgNPs. This is due to the presence of a strong H-binding interaction between the bio-composite matrix and the AgNPs molecules. The results revealed that the incorporation of 20% AgNPs into the CS:CL-CNC7:3–50% bio-composite film could be the best candidate composition for all optical properties. It can be used for potential applications in the area of food packaging as well as successfully on opto-electronic devices.

In recent years, macroalgae and microalgae have played a significant role in the production of organic matter, fiber, and minerals on Earth. They contribute to both technical and medicinal applications as well as being a healthy and nutritious food for humans and animals. The theme of this work concerns the development and exploitation of Chaetomorpha linum (C. linum) biomass, through the elaboration of a new starch-based composite film reinforced by cellulose nanocrystals (CL-CNC) derived from C. linum. The first step involves the chemical extraction of CL-CNC from dry C. linum algae biomass. To achieve this, three types of cyclic treatment were adopted: alkalinization (sodium hydroxide) followed by bleaching (sodium hypochlorite) and acid hydrolysis (hydrochloric acid). We then studied the optimization of the development of bio-composite films based on corn starch (CS) reinforced by CL-CNC. These polymeric films were produced using the solution-casting technique followed by the thermal evaporation process. Structure and interactions were modified by using different amounts of glycerol plasticizers (20% and 50%) and different CS:CNC ratios (7:3 and 8:2). These materials were characterized by UV visible (UV/Vis), Fourier Transform Infrared (FTIR) and Scanning Electron Microscope (SEM) spectroscopy to understand structure-property relationships. The result revealed that the best matrix composition is 7:3 (CS: CL-CNC) with 50% glycerol, which reflects that the reinforcing effect of CL-CNC was greater in bio-composites prepared with a 50% plasticizer, revealing the formation of hydrogen bonds between CL-CNC and CS.

A water-soluble polysaccharide from the green alga Chaetomorpha linum , designated CHS2, was obtained by water extraction, preparative anion-exchange and size-exclusion chromatography. Results of chemical and spectroscopic analyses showed that CHS2 was a sulfated rhamnogalactoarabinan, and its backbone was mainly constituted by 4-linked and 3,4-linked β- l -arabinopyranose with sulfate groups at C-2/C-3 of 4-linked β- l -arabinopyranose. The branching contained 4-linked, 6-linked β- d -galactopyranose and terminal rhamnose residues. Based on the inhibition of human islet amyloid polypeptide (hIAPP) aggregation and morphology change of hIAPP aggregates in in vitro tests, it was proved that CHS2 effectively inhibited the hIAPP aggregation and possessed strong antidiabetic activity. CHS2 was nearly no toxicity in NIT-1 cells and could attenuate hIAPP-induced cytotoxicity. CHS2 may significantly reduce the generation of intracellular reactive oxygen species and hIAPP aggregation-induced oxidative stress in NIT-1 cells. CHS2 was co-localized with mitochondria, and largely protected mitochondria function from hIAPP aggregation-induced damage through stabilizing mitochondrial membrane potential and enhancing the mitochondrial complex I, II or III activity and ATP level. The data demonstrated that CHS2 could have potential prospect to become an antidiabetic drug for type 2 diabetes mellitus treatment. [ABSTRACT FROM AUTHOR]

This study analyzed the ethyl acetate-methanol extracts of tropical green seaweeds for phytochemical indicators and antioxidant activities. Compositional analysis of the organic extracts of green seaweeds Ulva lactuca (formerly Ulva fasciata), Halimeda macroloba, Chaetomorpha linum and Chaetomorpha antennina identified the presence of phytoconstituents, such as total phenols, terpenoids, saponins and flavanoids. U. lactuca exhibited higher levels of total phenols (59.8 mg GAE/g), saponins (1.77 %), flavanoids (2.3 %), as well as greater 2, 2-diphenyl-1-picrylhydrazylradical radical quenching activity (DPPH.IC50 0.86 mg/mL). Extracts of U. lactuca and H. macrobola showed promising antimicrobial activities against Vibrio parahaemolyticus. Proton nuclear magnetic resonance fingerprint analyses of the solvent extracts showed that higher proton integrals were present in the downfield regions in U. lactuca, which could be responsible for lowering DPPH activity. The present work supports that the renewable green seaweed U. lactuca could be used to isolate prospective bioactive leads. [ABSTRACT FROM AUTHOR]

The current research focused on algae from the waters of the Black Sea—Chaetomorpha linum, Ulva intestinalis, Ericaria crinita, and bioreactors—Chlorella spp. and Arthrospira platensis/cyanobacterium/. Pigment content, total phenolic content, and antioxidant capacity were investigated for their use as pharmaceutical, food, and cosmetic ingredients. E. crinita exhibited the highest antioxidant activity by ORAC and HORAC (463.3 µmol TE/g and 463.3 µmol GAE/g) and the highest total content of polyphenols and rutin of the investigated algae. Lower protein content was found in saltwater algae than in freshwater algae. For the first time, biologically active substances from the Bulgarian A. platensis and Chlorella spp., produced in a bioreactor, have been quantitatively identified. A. platensis contained rutin (141.25 mg/100 g), naringenin (42.17 mg/100 g), quercetin (26.74 mg/100 g), kaempferol, and quercetin-3-β-glycoside. Phenolic acids were isolated: neochlorogenic (172.27 mg/100 g) for lyophilized and 5783 mg/100 g for convection-dried A. platensis. It has been found that the protein content in A. platensis (convection dried) and Chlorella spp. (lyophilized) was nearly 54% higher than that of green algae U. intestinalis from Varna. The lyophilization process reduced the protein content of A. platensis samples by almost 20%. The high protein content of convection-dried A. platensis (43.4%) and lyophilized Chlorella spp. (43.7%) identified them as suitable emulsifiers in colloidal and emulsion systems.

The green approach of nanoparticle synthesis has gained more attention by researchers because of its nontoxic, eco-friendly, biocompatible, and sustainable nature. The present research investigated the anticancer effectiveness of silver nanoparticles synthesized from marine algae Chaetomorpha linum (C. linum) against colon cancer cell HCT-116 in vitro. Biosynthesized silver nanoparticles (C-AgNPs) are characterized using UV-spectrophotometry, dynamic light scattering (DLS), X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). We demonstrated the dose-dependent cytotoxic effect of C-AgNPs in human colorectal carcinoma cells (HCT-116) using MTT assay. The apoptosis induction in HCT-116 cells caused by C-AgNPs has studied fluorescence microscope by staining with fluorogenic agents 4′,6-diamidino-2-phenylindole (DAPI), rhodamine 123, and 2′,7′-dichlorodihydrofluorescein diacetate (H2DCFDA). By using a flow cytometric test, the apoptotic action of C-AgNPs was performed. The immunoblotting study of caspases, as well as pro-apoptotic and anti-apoptotic protein expression, was studied using the PCR technique to understand the underlying molecular mechanism of C-AgNPs on cancer cells. The apoptotic studies showed an increase in the expression of apoptotic caspase 3, caspase 9, BH3-interacting domain death agonist (Bid), and Bax, along with a decrease in the anti-apoptotic protein like Bcl-2 and Bcl-xl, thereby veritably confirmed by immunoblotting and qPCR technique. The biosynthesized C-AgNPs was an efficient anticancer agent that can induce apoptosis in the HCT-116 colon cells. [ABSTRACT FROM AUTHOR]

Green seaweeds (Chlorophyta) are often considered a nuisance, but may in fact constitute a potential climate-friendly renewable resource in the new bioeconomy. Utilization of green seaweed polysaccharides could in particular enable a new type of green growth in coastal regions in developing countries e.g. in West Africa. The carbohydrate constituents, including cellulose, are lignin-free, but only limited knowledge is available on the cellulose ultrastructure and cellulose crystallinity in commonly occurring green seaweeds. Abundantly available green seaweeds along the coast in West Africa include Chaetomorpha linum, Caulerpa taxifolia, Ulva fasciata and Ulva flexuosa. Here, using X-ray diffraction (XRD), on cellulose gently purified from the green seaweeds, we determined that mainly cellulose Iα was present in both C. linum and U. flexuosa. We also found that the crystallite diameter was particularly large, 16 nm, in both the Ghanaian and the Danish C. linum samples, especially compared to the crystallite diameter of 2.5–5 nm in most terrestrial vascular plants (Tracheophytes), which mainly contain cellulose Iβ. For U. flexuosa, increasing crystallinity of the cellulose was achieved during purification. Cellulose purification was not achievable for C. taxifolia, indicating that in this species the glucose is mainly a constituent of other carbohydrates, presumably notably of starch. Transmission electron microscopy (TEM) confirmed the large size of the crystallites of C. linum showing the cellulose forming a multi-lamellar structure with alternating perpendicular and parallel layers along the fibre axis. The cell wall nano-structure appeared amorphous in C. taxifolia and as a network in U. fasciata and U. flexuosa. As glucose was most abundant in C. linum and its cellulose was crystalline, this green seaweed species appears particularly promising as a source for manufacturing of novel cellulose-based materials, e.g. specialized paper or cellulose-based composite materials. [ABSTRACT FROM AUTHOR]

A novel polysaccharide extracted from green algae Chaetomorpha linum (PS) was characterized, using infrared spectroscopy, HPLC-FID, gel filtration high-pressure chromatography, thin layer chromatography and spectrum visible UV. Natural antioxidant potential of PS was evaluated based on DPPH free radical, ferrous iron–chelating, β carotene bleaching inhibition activities and DNA nicking assay. Functional properties were estimated based on Water Holding Capacity (WHC), Oil Holding Capacity (OHC), emulsifying activity and foaming ability. Overall, data showed attractive chemical, functional and biological properties with an antioxidant capacity of PS in beef sausages during storage for 12 days. Indeed, as compared to standard formulation (with addition of vitamin C), samples formulated with PS presented lower values in terms of lipid oxidation (TBARS, MetMb), while preserving color properties compared with untreated samples. Furthermore, lower changes in pH, moisture, and the highest values of heme iron were obtained. Successful inhibition of microbial proliferation was proved. Endowed with high antioxidant and antimicrobial activities, PS could thus be used as a natural conservative in functional foods. • Polysaccharide (PS) was extracted from green algae Chaetomorpha linum. • PS exhibited potent functional and antioxidant activities. • PS was added, for the first time, as antioxidant food additive in beef sausages. • PS inhibited the lipid oxidation of beef sausages for 12 days refrigerated storage. • PS improved the color and microbial stability of beef sausages of storage time. [ABSTRACT FROM AUTHOR]

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Chaetomorpha linum is a bloom-forming macroalgae found all over the world. In the past 10 years, green tides dominated by Chaetomorpha spp. have broken out frequently in the phosphate-deficient Swan Lagoon, China. Here, we evaluated the changes in P concentration and alkaline phosphatase activity (APA) in water and sediments during the growth of C. linum in the laboratory experiment. The objective of this study was to clarify the phosphorus (P) sources supporting the C. linum blooms throughout the year in this phosphate-deficient lagoon. Our results show that C. linum is able to store a large amount of P when phosphate is abundant in the water, and the P in algal tissue can be utilized for algal growth at a short time. This species can also produce alkaline phosphatase (APase) and facilitate the release of mobile P (BD-P and NaOH-P) from sediments when phosphate is deficient in order to sustain growth. The field investigation shows the seasonal differences in the P sources supporting C. linum blooms in Swan Lagoon. In addition to sediment released P, the tissue P in living algae and the dissolved organic P in water are the main utilized P sources in spring and winter, respectively. This possibly explains why C. linum can persist and proliferate in such a lagoon system throughout the year. • We evaluated the changes in P concentration and APA in water and sediments during the growth of 'green tide' C. linum. • At low P treatments without sediment, high APA was induced after 1 week as the P pool in C. linum was gradually depleted. • The dissolved OP could be utilized via APase for C. linum growth under phosphate deficiency. • The massive proliferation of C. linum promoted the release of mobile P (BD-P and NaOH-P) from lagoon sediments. [ABSTRACT FROM AUTHOR]

Seagrass meadows are declining at alarming rates globally due to both anthropogenic activities and natural threats. Seagrasses play key ecological roles in coastal ecosystems as primary producers and providers of habitat and environmental structure. Therefore, mapping seagrass beds is indispensable for the effective monitoring and management of coastal vegetated habitats. In contrast to direct sampling techniques and optical remote sensing, active hydroacoustic techniques are relatively inexpensive and efficient for the detection of seagrass. We used a single beam echosounder to detect the spatial and temporal distribution characteristics of the eelgrass Zostera marina L. in an important overwintering habitat for the whooper swan Cygnus cygnus (Swan-Lake lagoon), northern China. We also distinguished echograms of the macroalgae Chaetomorpha linum K. and outlined its threat to seagrass. We also propose a method for calculating the accuracy of interpolation analyses. Results showed that: (1) The distribution of seagrass in Swan Lake varies with seasons, with maximum distribution area in summer. The maximum distribution area of seagrass beds in Swan Lake was 199.09 ha–231.67 ha, accounting for 41.48%–48.26% of the area of Swan Lake; (2) C. linum is a growing threat for seagrass beds of Swan-lake, with distribution area as high as 129.28 ha in May 2018. The invasion and competition by C. linum against seagrass beds could be one of the reasons for the decline in seagrass beds in Swan-Lake; (3) Topo to Raster has the highest interpolation accuracy and is the most conservative among three interpolation methods. Topo to Raster was the most suitable interpolation method for the sonar detection of seagrass beds. The findings may facilitate the application of sonar technology in seagrass monitoring and provide data for the formulation of appropriate seagrass bed management and restoration strategies and policies. Unlabelled Image • Eelgrass in a swan-overwintering lagoon was detected by sonar. • A new method to calculate the accuracy of interpolation analysis was proposed. • Topo to Raster is the most suitable interpolation method for sonar detection. • C. linum bloom is a growing threat to seagrass beds in Swan-lake. [ABSTRACT FROM AUTHOR]

Saline lagoons are priority habitats in the United Kingdom supporting several protected specialist species. One specialist, the amphipod Gammarus insensibilis , is infected with behaviour-altering microphallid trematodes such as Microphallus papillorobustus. In saline lagoons around the coast of England (Gilkicker and Lymington–Keyhaven on the Hampshire coast and Moulton Marsh in Lincolnshire) there is variation in the prevalence of this parasite in the gammarid populations (0 at Salterns in the Lymington–Keyhaven lagoon system to 98% at Gilkicker). Infection intensity ranged from 0 to 20 metacercariae in individual amphipods. Higher infection intensity can alter the shape of the amphipod's head. Under experimental conditions respiration rate is significantly reduced in infected animals and reproductive output (expressed as early stage embryos mg g dry weight−1) is significantly lower in infected females. It is important to consider the role of host–parasite interactions in order to understand the ecology of specialist lagoon species such as G. insensibilis and their lagoon habitats. [ABSTRACT FROM AUTHOR]

Seasonal changes of high density Chaetomorpha linum mats were studied in an eutrophic coastal lagoon. We measured biomass and specific growth rate and analyzed water quality, sediment labile organic matter (LOM), photosynthetic efficiency and pigments in two areas: one subjected to sediment resuspension and algal mass shuffling through specific boats and the other left undisturbed. Low disturbance enhanced algal survival under critical summer conditions, by reducing LOM and promoting growth through thalli fragmentation. Chaetomorpha linum grew fast and quickly acclimated its physiology to adverse conditions, although the mat underlayer showed low photosynthetic efficiency. Nevertheless, the ability to respond to the adverse environment was not sufficient to prevent the sudden algal decay, which occurred following a prolonged summer stress. Present results may help to plan the lagoon management through boat operations, to attain a more effective control over the algal growth and a more efficient removal of the mat. [ABSTRACT FROM AUTHOR]

The potential of Caulerpa lentillifera, Gracilaria coronopifolia and Chaetomorpha linum, as biomass feedstock was investigated in this study. It was concluded that seaweed is more suitable for bio-based products synthesis, i.e., bioplastic and bio-lubricants, instead of biofuels due to its relatively low calorific value (~12 MJ/kg). Since seaweed has high moisture content (~80%), hydrothermal liquefaction is recommended, and its efficiency can be further enhanced through microwave technology. Besides, it is found that the thermal degradation of seaweed was best described with the reaction order of 1. The kinetic results also indicated that seaweed consists of lower activation energy (Chaetomorpha linum, as it has no conflict with other interests. Lastly, acetic-acid pre-treatment was suggested to be an optional process in order to increase the algal conversion efficiency as it can reduce up to 25% of ash content.

The Nador lagoon is one of the best lagoons in the Mediterranean, it currently suffers from eutrophication caused by algae proliferation. In this study, we valorised the three important algae that are responsible for pollution of the lagoon. We determine their potential of biogas production and green energy capacities and we studied their effects on anaerobic bacteria proliferation in digester. After 40 days of incubation in batch mode we observed the red alga ( Alsidium corallinum ) produced the most biogas with 85.23 ml/gVS, which is equivalent to 511 kWh/tVS of green energy, whereas the brown alga ( Cystoseira barbata ) ranked second place with 76.45 ml/gVS of biogas product, the equivalent to 458 kWh/tVS of green energy. But, the green alga ( Chaetomorpha linum ) produced the least biogas do not exceed 22.23 ml/g VS, so these algae produces the lowest amount of energy green 133 kWh/tVS. Thus, this red alga ( Alsidium corallinum ) were considered excellent substrate for anaerobic digestion. These results correlated with the anaerobic bacterial proliferation of the inoculum, where the two algae ( Alsidium corallinum and Cystoseira barbata ) led to a large proliferation of anaerobic bacteria, from 1.8 × 10 5 CFU/g to 61 × 10 5 CFU/g, followed by the green alga. Therefore, we consider these three algae ( Alsidium corallinum, Cystoseira barbata, and Chaetomorpha linum ) as an exploitable energy reservoir in Nador lagoon. Finally, we propose that a new system which will halt eutrophication of this lagoon, it comprising anaerobic digestion of these algae, be installed to produce green energy for a lagoon aerator to dissolve the atmospheric oxygen inside the lagoon. [ABSTRACT FROM AUTHOR]

Apostichopus japonicus is one of the main aquaculture species in northern China. The green tide macroalgae Chaetomorpha linum and the seagrass Zostera marina occur in this region. Our previous study has suggested that Z. marina detritus can be a food source for A. japonicus . In the present study, we carried out a laboratory simulation experiment for 60 days to understand whether C. linum can also be utilized to fulfill the nutrient demands of A. japonicus . The powdered C. linum and Z. marina detritus, mixed in five ratios (100:0; 75:25; 50:50; 25:75; 0:100), were fed to sea cucumbers along with muddy sediment in a fixed proportion. Sargassum thunbergii (40%) combined with the muddy sediment (60%) was also used as a standard reference/control diet. Results showed that the specific growth rates (SGRs), food utilizing efficiencies and energy budgets of A. japonicus were strongly influenced by the ratio of C. linum and Z. marina in their diets. The growth energy deposited in the bodies of sea cucumbers fed higher proportions of C. linum was significantly higher than those fed higher proportions of Z. marina . Furthermore, sea cucumbers fed on C. linum and S. thunbergii had similar growth performances. This study indicated that C. linum could replace S. thunbergii as a food source for A. japonicus . Statement of relevance Because of its high nutritive and medical properties, the sea cucumber Apostichopus japonicus has become a highly valuable fishery and aquaculture species in Asia. Influenced by eutrophication in coastal waters, blooming events of the green tide algae Chaetomorpha linum are increasing around the world, including some natural habitats for A. japonicus in northern China. However, whether C. linum can also be utilized to fulfill the nutrient demands of sea cucumbers, such as A. japonicus , is unknown. We carried out a laboratory simulation experiment for 60 days to study this question. Our results showed that sea cucumbers fed on C. linum and Sargassum thunbergii had similar performances. Due to its higher protein and lower cellulose contents, C. linum was easier for A. japonicus to digest and absorb, and more energy per unit of food was converted to growth. This study indicated that C. linum could act as a food source for A. japonicus . The results of this research are also beneficial for promoting the collection and control of C. linum . [ABSTRACT FROM AUTHOR]

We report the presence of persistent blooms of Chaetomorpha linum in San Andres island, Southwestern Caribbean, during the year 2013. RESUMEN Reportamos la presencia de florecimientos persistentes del alga verde Chaetomorpha linum en la isla de San Andrès, Caribe suroccidental.

Green macroalgae Chaetomorpha aerea and C. linum are taxonomically confused. In this paper, we tried morphological and molecular analyses to separate these two species. C. aerea and C. linum can be distinguished from morphological characteritics, such as frond dimension, cells size and shape, their mean length/width ratios (LWR), and cell walls constriction. Thalli of C. aerea attenuate basipetally, with diameter 270-500 μm at upper portion, 160-360 μm at middle portion, 100-160 μm at basal portion. For the upper part, the length of cells is less than their diameter. Cell walls usually constrict at the dissepiments, which are pellucid or colorless and give the filament beaded appearance. In contrast, thalli of C. linum often have a constant diameter of 90-300 μm within the same individual, cell walls usually do not constrict and cells are cylindrical or barrel shaped. The LWR is larger than that of C. aerea. Results show that the pairwise distance between two species is 3.6%-3.7% for 18S rRNA gene and 53.5%-54.3% for ITS region. In phylogeny, they distribute at distant clades, which confirms a genetic divergence at molecular level. In addition, morphological data indicates that filament diameter of C. linum samples is highly variable, ranging from 90 μm to 300 μm. Then these two species can be considered as separate species. [ABSTRACT FROM AUTHOR]

Effects of environmental factors on the zoospore release and germling growth of Chaetomorpha linum were examined. Zoospore release and germling growth experiments were carried out under a combination of temperatures × irradiances, and a single factor of irradiances, salinities, daylength and nutrients (nitrogen, phosphorus). Zoospore release was maximal under condition of 20°C × 100 μmol photons m−2s−1 in a factorial experiment (temperatures × irradiances), at 100 μmol photons m−2s−1 in irradiance experiment and at 34 psu in salinity conditions. After 24 days in culture, germling growth was maximal at 25°C × 100 μmol photons m−2s−1 in temperatures × irradiances and at normal seawater (34 psu) in salinity. Germling growth is faster at higher irradiance under same temperature condition and it increased with increasing daylengths (8−16 h). Chaetomorpha linum grew in wide range of N and P concentrations. The growth of germling was maximal at 50 μM PO43− and 40 μM NH4+. Germling growth was more effective under nitrogen addition than phosphorus addition in culture. In conclusion, optimal environmental conditions for zoospore release were 20°C, 100 μmol photons m−2s−1, and 34 psu. In addition, the optimal germling growth was observed at 25°C, 100 μmol photons m−2s−1, 34 psu, 16 h, 50 μM (PO43−) and 40 μM (NH4+). [ABSTRACT FROM AUTHOR]

In spring 2014, thousands of green algal balls were washed up at Dee Why Beach, Sydney, New South Wales, Australia. Reports of algal balls are uncommon in marine systems, and mass strandings on beaches are even more rare, sparking both public and scientific interest. We identified the algal masses as Chaetomorpha linum by using light microscopy and DNA sequencing. We characterize the size and composition of the balls from Dee Why Beach and compare them to previous records of marine algal balls. We describe the environmental conditions that could explain their appearance, given the ecophysiology of C. linum. [ABSTRACT FROM AUTHOR]

We report the presence of persistent blooms of Chaetomorpha linum in San Andres island, Southwestern Caribbean, during the year 2013. [ABSTRACT FROM AUTHOR]

In summer 2012, an experiment was conducted in a shallow eutrophic lagoon with poor water exchange to determine the consequences of harvesting algae on the algal mat itself, which was traversed and repeatedly disturbed by large harvester boats. Four areas with high macroalgal density, measuring half a hectare each, were selected. Two were subjected to frequent disturbance of the algal mat and sediment (12 two-hour operations over a 38-day period) and the other two were left undisturbed as control. The following variables were determined: 1) water column physical chemistry and nutrients; 2) redox potential, nutrients and organic load in sediments; 3) C, N and P content of algal thalli; 4) macroalgal biomass. In 2013, a further experiment was conducted on a larger scale. Biomass was estimated in a high-density mat measuring 235 ha, where macroalgae were harvested and stirred up by four harvesting boats, and in two high-density mats measuring 150 and 120 ha, left undisturbed as control (9.15, 9.92 and 3.68 kg/m 2 , respectively). In the first experiment, no significant changes were observed in the water column. In sediment the main variation was a significant reduction in labile organic matter in the disturbed areas and a significant increase mainly in refractory organic matter in the undisturbed areas. Biomass showed a significant drastic reduction in disturbed areas and substantial stability in undisturbed areas. In the large-scale experiment, the biomass of the disturbed mat declined by about 63%, only 6.5% of which was due to harvesting. On the other hand, the undisturbed mat with higher density underwent a natural decline in biomass of about 23% and the other increased by about 50%. These results demonstrate that disturbance of high-density mat in shallow water by boats can cause decay of the mat. [ABSTRACT FROM AUTHOR]

Highlights: [•] Comparison of 5 pretreatment methods for Chaetomorpha linum for ethanol production. [•] Pretreatment with wet oxidation and ball milling resulted in highest ethanol yield. [•] Ball milling resulted in 64% higher ethanol yield compared to unpretreated C. linum. [•] The ethanol yield was higher than found in literature for other macroalgae. [ABSTRACT FROM AUTHOR]

Abstract: A laboratory experiment was conducted to assess the effect of filamentous algae mats on the performance of seedlings of the eelgrass, Zostera marina. The seedlings were covered by three levels (3, 6 and 9cm) of natural (Chaetomorpha linum) and imitation algae mats and it was hypothesised that the effects of the natural algae on seedling growth may be more severe because of the metabolic demands of the algae. Results show that coverage by both C. linum and imitation algae significantly reduced seedling growth and increased allocation of resources to above ground tissues. No clear effects of algae type on seedling performance were found and since there were no differences in oxygen or sulphide concentrations between the treatments, we attribute the reductions in seedling growth to algal shading. In a comparison with other studies it is shown that lower turbulence, higher temperature, organically enriched sediments and longer duration of exposure than applied here may result in oxygen depletion thereby intensifying the negative effects of light attenuation by algal mats on seedling performance. [Copyright &y& Elsevier]

Abstract: The filamentous chlorophyte Chaetomorpha linum (Müller) Kützing can stand wide changes in salinity occurring in brackish and estuarine waters. In an attempt to characterize C. linum adaptation, a NaCl-induced ascorbate oxidase (AAO) activity was identified and partially characterized. Immunogold-transmission electron microscopy analysis showed AAO labelling in the cytosol, walls and chloroplasts of C. linum cells, whereas in angiosperms this enzyme is almost exclusively confined to the extracellular matrix. The possible function of AAO in adaptation and functional evolution of its cellular location is discussed. [Copyright &y& Elsevier]