Sea moss has gained popularity as a functional food, yet information on the microbial quality, physicochemical characteristics, and heavy metal concentrations of commercially available products remains limited. This study evaluated 66 sea moss products purchased from major online retailers in the United States, including 53 dried sea moss products and 13 sea moss gels. Water activity ranged from 0.33 to 0.76 (0.59 ± 0.11) in dried sea moss and from 0.74 to 1.00 (0.98 ± 0.07) in gels. Sea moss gels exhibited substantial variability in pH (2.71-7.05) and °Brix (0.80-46.10). Mean total plate counts were 4.30 and 3.92 log CFU/g in dried sea moss and gels, respectively, while mean yeast and mold counts were 3.23 and 3.60 log CFU/g. Presumptive Bacillus and Staphylococcus spp. were recovered from both product types, while presumptive Escherichia, Salmonella, Listeria, and Vibrio spp. were detected less frequently. Molecular characterization of selected isolates identified Bhargavaea, Exiguobacterium, Staphylococcus, Salmonella, Cronobacter, Bacillus, and Escherichia spp.; Listeria and Vibrio spp. were not identified among isolates yielding interpretable sequence results. Arsenic, cobalt, and mercury were detected in dried sea moss, whereas arsenic and cobalt were below the limits of detection in the gels and mercury was detected at trace concentrations. Substantial variability in microbial and physicochemical characteristics among commercial sea moss products highlights the need for additional research and evidence-based guidance to support appropriate processing, storage, and handling practices.

Cannabidiol (CBD) is a lipophilic phytocannabinoid of interest for dermocosmetic and topical applications, but its poor aqueous solubility and sensitivity to environmental conditions make its formulation challenging. This work aimed to develop avocado oil-in-water emulgels for CBD incorporation using a mixed emulsifying system based on Kolliphor EL and cricket protein and a commercial Aloe vera/Chondrus crispus gel as the structuring phase. First, different Kolliphor EL:cricket protein ratios were evaluated according to droplet size distribution. No significant differences in droplet size were found among formulations containing at least 67% Kolliphor EL (p > 0.05); therefore, 67K-33G was selected because it maximized the substitution of Kolliphor EL with cricket protein without significantly affecting droplet size. Progressive replacement of water by the commercial hydrocolloid gel markedly increased consistency and viscoelasticity, producing a transition from fluid emulsions to elastic emulgels between 50 AV and 75 AV. The 75 AV formulation showed low Turbiscan Stability Index values, a predominantly elastic response, and a more balanced structure than 100 AV. The selected emulgel showed a total analytical recovery of 96.2 ± 1.2% for CBD and retained 97.3 ± 0.7% of the initially recovered CBD after 30 days of storage at 4 °C protected from light. These results support the potential of Aloe vera/Chondrus crispus-based emulgels as semisolid carriers for lipophilic bioactive compounds.

Vanadium-dependent haloperoxidases are enzymes found in bacteria, fungi and red or brown macroalgae. They are used as a defense system for the latter by producing bromoform. The intermediate product, HOBr or HOCl, is also a microbicidal compound that can be exploited in many domains as medical tools or disinfectant sprays for example. We show that the mutation identified in Ohshiro's work, which alters substrate specificity toward chloride, is transferable to the homologous enzyme from Chondrus crispus. We then applied genetic and enzymatic engineering to design a chimera with glucose oxidase, thereby enhancing antimicrobial properties by providing a local source of H2O2. We used the SpyTag/SpyCatcher technology to form the chimera and obtained homogenous objects, indicating that one oligomeric form is favored. We demonstrated the release of HOBr and HOCl thanks to NADH that reacts spontaneously with it outside the active site of the enzyme. We also measured the steady-state kinetic parameters of the wild-type or modified enzymes. The formation of the chimera increased the specificity of ccVHPO1 inside the chimera, towards KBr or H2O2, compared to the enzyme alone with the SpyCatcher. Finally, we showed a significant increase in the microbicidal effect between a coupled enzymatic system with the glucose oxidase (the two enzymes are free in solution) compared to the chimera system, which is completely bactericidal at concentrations around 20 nM.

Structural coloration, a physical phenomenon observed in many living organisms, may arise from the interference of light with highly organized surface nanostructures. In some seaweeds, these nanostructures consist of cuticular lamellae in the outer part of the extracellular matrix (ECM) of the epidermis. However, the chemical composition of seaweed cuticles is poorly understood and the molecular components of lamellae remain unidentified. Here, we use integrated genomic, transcriptomic, proteomic, and metabolomic approaches together with analytical profiling of carbohydrates to determine the composition of the multilayered cuticle in the red alga Chondrus crispus and assess its evolutionary conservation. The structural assembly reveals common features with the ECM of animals. The carbohydrate fraction includes a complex mixture of carrageenans and glycosaminoglycan-like compositions. A major von Willebrand factor A domain protein, Lamellae Cohesive Protein, plays a critical role in protein-protein interactions and binding to sulfated polysaccharides. We have further identified the major proteins of the algal cuticle, providing a framework for addressing the evolutionary origins of the cuticle and raising important questions regarding its role, particularly across the red algal life cycle marked by major structural differences in its ECM.

A quantitative NMR assay was utilized to identify methylglyoxal-scavenging natural products from Rhodophytes, Chondrus crispus and Gracilaria vermiculophylla. This revealed the activity of guanylurea-containing amino acid derivatives, gongrine and gigartinine. The molecules share structural features with the frontline blood glucose-lowering drug and plant natural product derivative, metformin, and scavenge methylglyoxal via the same mechanism, resulting in an imidazole-containing Advanced Glycation Endproduct or AGE. The protective effect of the molecules reported here was evaluated in a cell-based model for reactive aldehyde stress using methylglyoxal exposure to reduce cell viability. Gongrine, gigartinine, and metformin all preserve cell viability in HepG2 following methylglyoxal exposure. This is the first report of methylglyoxal scavenging and cell viability protection of these macroalgae-derived guanylurea-containing natural products, which can be found in high abundance in commonly consumed and industrially produced macroalgae species. The compounds presented here, along with their algal sources, offer a unique opportunity to produce guanylureas with therapeutic potential through sustainable production methods from easily cultivated algal sources.

Mycosporine-like amino acids (MAAs) are photoprotective compounds primarily produced by marine organisms, especially red algae. Chemically, MAAs and their precursors are low-molecular-weight natural products that absorb ultraviolet radiation in the range of 270-360 nm without generating free radicals. Owing to these properties, MAAs have attracted considerable interest for potential pharmaceutical and cosmetic applications as natural sunscreen agents. In this study, the first hydrophilic interaction liquid chromatography-ultra-performance liquid chromatography (HILIC-UPLC) method, coupled with both diode array detector (DAD) and tandem mass spectrometry (MS/MS), was developed for the determination of 11 MAAs and 2 MAA precursors in various algal species. As column, a YMC-Triart Diol-HILIC (particle size: 1.9 µm) was used, and the separation of the MAAs realized in under 5 min. The validation of the method was carried out following International Council for Harmonisation (ICH) guidelines, demonstrating linearity, selectivity, precision, and accuracy. The analysis of extracts prepared from well-known species, such as Porphyra sp. and Chondrus crispus, confirmed practical applicability. Demonstrating feasibility of MS/MS-based quantification of co-eluting compounds, the method represents an appealing alternative that surpasses established procedures not only in terms of analysis time but also by providing a substantially increased informative value.

Sulfated polysaccharides, carrageenans (CRGs) derived from Chondrus armatus, were used as mucoadhesive matrices for incorporating the antiviral drug acyclovir (ACV). Through IR spectroscopy and quantum-chemical calculations, it was demonstrated that CRGs interact with ACV, forming complexes via intermolecular hydrogen bonding and coordination interactions, with an enthalpy of approximately 15-20 kcal/mol. The monomodal ζ-potential distribution observed in the CRG/ACV mixture confirmed the successful formation of this complex. The antiviral efficacy of the CRG/ACV complex was evaluated during the early stages of herpes simple virus (HSV-1) infection, focusing on its ability to inhibit the cytopathic effects of the virus on host cells. Notably, CRGs enhanced antiviral activity by allowing a reduction in the ACV dosage. Unlike ACV alone, the CRG complex exhibited a prophylactic effect, with therapeutic efficacy comparable to that of ACV. When incorporated into liposomes, the CRG/ACV complex displayed excellent mucoadhesive properties. This liposomal formulation demonstrated notable antiviral activity against infected cells with selective index (SI) 344 and a heightened prophylactic effect (SI 128) compared to the complex alone. Overall, these new antiviral compounds show promise in selectively inhibiting viral adsorption and replication processes without adversely affecting the host organism.

A novel cold-adapted κ-carrageenase (Car2891) was identified from the marine bacterium Cellulophaga sp. P-1 isolated from Chondrus. The enzyme was recombinantly expressed in E. coli BL21(DE3) and biochemically characterized. Car2891 exhibited optimal activity at 30 °C and pH 8.0, maintaining high stability and catalytic performance from 0 °C to 30 °C under neutral-weakly alkaline conditions. Its activity was enhanced by Na[+], Mg[2+], and Mn[2+] but strongly inhibited by Hg[2+], Cu[2+], Ni[2+], and EDTA. Kinetic analysis revealed a Km value of 6.1 mg mL[-1] and a Vmax value of 31.65 mg mL[-1] min[-1] for κ-carrageenan. Hydrolysis pattern analysis revealed an endo-acting cleavage mechanism, initially yielding hexa- and tetrasaccharides, with disaccharides and tetrasaccharides as the final major products. These properties demonstrate Car2891's potential as an efficient and controllable biocatalyst for the environmentally friendly processing of κ-carrageenan and the scalable production of functional oligosaccharides.

Seaweed are primary producers and potential vectors of microplastics (MPs) contamination, yet robust extraction methods that digest complex algal matrices while preserving polymer integrity remain limited. A sequential enzymatic-oxidative digestion was optimized for three seaweeds (Fucus vesiculosus, Chondrus crispus and Ulva lactuca). The optimized process involved the initial addition of cellulase (1% w/v, 24 h, 50 °C) followed by H₂O₂ (30% v/v, 48-72 h, 65 °C). Across nine 0.5 g dry-weight sub-replicates (3 per seaweed), 30 MPs were found (6.7 MPs/g⁻¹). The integrity of polymers was assessed for 12 MPs polymers, with acceptable performance being defined as ≥ 90% recovery and spectroscopic (through FTIR analysis) identifiability. Eight polymers met this threshold (90-101%). Four polymers were adversely affected with the long 72 H₂O₂ incubation, namely: cellulose-acetate (53% recovery), polyamide (61%), acrylic (3%) and rayon (2%). Although polymers remained identifiable, sequential digestion produced mass loss and visible changes (e.g. polyamide opacity, cellulose-acetate brittleness), which may increase fragmentation and miss-identification. Therefore, the protocol is suitable for most common MPs, but not for rayon and acrylic, and should be applied cautiously where cellulose-acetate or polyamide are expected.

Gloiopeltis furcata is an annual red alga of Endocladiaceae, Florideophyceae, showing high economic and medical values. The chloroplast genome is instrumental for evolutionary studies, yet that of G. furcata remains unreported. Here, the chloroplast genome of G. furcata was assembled and analyzed. The genome size is 177,606 bp, which contains 184 genes (152 protein-coding genes, 29 tRNAs, and 3 rRNAs).  Four simple sequence repeat (SSR) types were detected. The AGA-encoded arginine had the highest relative synonymous codon usage (RSCU) value, while CGG-encoded arginine had the lowest. Phylogenetic analysis indicated that G. furcata is a sister to Chondrus crispus.

Sea moss or Irish moss (Chondrus crispus) is a type of red seaweed that is used as food and medicine, although no medicinal value has been proven. Sea moss contains carrageenan, which is used as food additive and other polysaccharides (carbohydrates). It also contains numerous minerals, including iodine and some toxic heavy metals such as arsenic, lead, cadmium and mercury that come from the water where it was grown.[1] Maternal consumption of excess iodine from seaweed has caused thyroid suppression in breastfed infants.[2-4] Sea moss should be avoided during breastfeeding unless the levels of iodine and heavy metals have been shown to be low enough to be safe.

We collected samples in the August (summer) and October (autumn) of 2022, as well as in the February (winter) and May (spring) of 2023 in the raft-style mussel aquaculture area on Gouqi Island in the Zhoushan Archipelago, aiming to analyze the structure of the raft-style algal community on Gouqi Island and its impact on the epibenthic preference of algae-dwelling amphipods (Gammaridea and Caprellidae). The results showed that: 1) The number of algal species and biomass on the nearshore side of the aquaculture area were higher than those on the offshore side, with seasonal fluctuations. The number of algal species was highest in summer (19 species) and lowest in winter (15 species). The species richness index was higher in summer (2.65) and lower in winter (2.38). 2) There were significant differences in the epibenthic density of Gammaridea and Caprellidae across seasons, with higher densities in summer and lower densities in winter. Gammaridea was predominantly distributed on the nearshore side of the aquaculture area, while Caprellidae was more abundant on the offshore side. 3) Both Gammaridea and Caprellidae preferred branching and foliar algae, with the foliar algae Chondrus ocellatus exhibiting the highest epibenthic density. Among the branching algae, Gammaridea tended to attach to the structurally complex and color-similar Grateloupia okamura, while Caprellidae preferred to attach to the rough-surfaced, hard-textured, and structurally stable Corallina officinalis. In addition to season, morphological characteristics such as branching number, surface roughness, and structural complexity were also major factors affecting the epibenthic preference of Gammaridea and Caprellidae. The study could contribute to understanding the ecological adaptation strategies of amphipods and provide theoretical basis and data support for ecological management and algal diversity conservation in raft-style aquaculture areas.

This study examined the biochemical composition and bioactivity of three macroalgae (seaweed) species: Palmaria palmata, Ascophyllum nodosum, and Chondrus crispus. Nuclear Magnetic Resonance spectroscopy identified 18 metabolites, including amino and organic acids with significant interspecies variation. Inductively Coupled Plasma analysis showed high calcium (up to 49,340 mg/kg in C. crispus) and iron (728.9 mg/kg in C. crispus), with trace arsenic and lead present. High-Performance Liquid Chromatography detected carotenoids lutein (0.0105 mg/mL) and α-carotene (0.0010 mg/mL) in P. palmata. Gas Chromatography-Mass Spectrometry revealed A. nodosum rich in oleic acid (57.3 %), P. palmata in palmitic acid (82.8 %), and C. crispus in myristic acid (48.7 %). Antioxidant assays showed C. crispus (IC₅₀ 5.33 mg/mL, DPPH) and A. nodosum (IC₅₀ 0.25 mg/mL, ABTS) had highest activity. Significant antibacterial inhibition zones (up to 4.67 mm) and 66.6 % biofilm reduction by C. crispus were observed. These macroalgae represent promising natural bioactive sources for food and health.

Plant protein consumption has increased globally but concerns exist regarding their ability to provide sufficient amino acids to consumers. Extraction methods that can separate protein from anti-nutritional factors have potential to increase the nutritional value of this biomass. Few studies concerning analysis of the amino acid content of plant protein extracts exist. In this work, three different protein extraction methods were used to generate protein extracts from Buckwheat, Spelt and the red seaweed Chondrus crispus. Methods used include ultra-sonication in water combined with ammonium sulphate-induced protein precipitation; an enzymatic extraction method using the enzymes Alcalase and Viscozyme, and an iso-electric precipitation extraction method using alkaline protein solubilization followed by acidic protein precipitation. Proteins extracted using the enzymatic method contained the highest proportion of essential amino acids (EAA) in viable quantities, and the method holds promise for use in the generation of alternative marine and cereal protein extracts for human consumption.