Seaweed Samples Research Articles

ICP-MS determination of background I-129 in seaweed samples around Fukushima Daiichi NPS.

TEPCO planned the release of Advanced Liquid Processing System (ALPS)-treated water, which is decontaminated stagnated water by ALPS, to the Pacific Ocean in 2023 after diluting it more than a hundred times in accordance with the policy of the Japan government. Since the low level of I-129 can remain in ALPS-treated water, the background I-129 concentration in seaweed samples around 1F NPS before the release of ALPS-treated water was recorded in this study. The iodine in seaweed samples was extracted via TMAH alkali-dissolution, and the I-129 concentration was measured by 8900 Triple Quadrupole ICP-MS. The resulting I-129 concentration was <5.4×10-2Bq/kg-wet (sargassum) and <2.7×10-2Bq/kg-wet (laminaria), respectively.

Potential role of alginate in marine bacteria-yeast interactions.

The ability of microorganisms to decompose brown algae has attracted attention. This study aims to clarify the characteristics of marine microbial communities in which prokaryotic and eukaryotic microorganisms interact via the metabolism of brown algae carbohydrates. Amplicon-based microbiome analysis revealed the predominance of the genera Marinomonas and Vibrio in seawater and seaweed samples mixed with alginate and mannitol, which are the primary carbohydrates in brown algae. Three Vibrio species and Candida intermedia were isolated via alginate enrichment culture. Although C. intermedia did not utilize alginate as a nutrient source, the yeast grew in the spent alginate medium in which Vibrio algivorus had been cultured. Coculture with C. intermedia and the Vibrio isolates, especially V. algivorus, also enhanced the growth of the yeast on alginate. These results suggested that C. intermedia grew because of the supply of nutrients via alginate metabolism by Vibrio species. In the coculture medium, the amount of phosphatidylserine increased in the early phase but decreased with the growth of C. intermedia, indicating that phosphatidylserine secreted by Vibrio is involved in the putative mutualistic interaction. We examined whether such interaction is applicable to the production of useful substances and succeeded in lipid production by oleaginous marine yeast Yarrowia lipolytica through coculture with V. algivorus. Our study suggested the potential of mutualistic interaction via degradation of alginate by marine Vibrio for production of industrially useful substances in yeast cells.IMPORTANCEIn this study, we analyzed the microbiome of seawater and seaweed in the presence of brown algae carbohydrates and reconstructed the putative mutualistic relationship of marine Vibrio and Candida intermedia mediated by metabolism of brown algae in the ocean.

Isolation, Characterization and Molecular Identification of Bacteria Associated with Green and Brown Seaweeds

Aims: The co-existence of bacterial communities along with macroalgae in marine environment develops a mutualistic relationship resulting in functional advantages for both the groups. The present research studied the composition of epiphytic bacteria associated with green (Ulva spp.) and brown seaweeds (Sargassum spp. and Padina spp.) sampled off Maharashtra coast, India, and their physiological and bioactive properties. Study Design: Green and brown seaweeds were collected from three locations along Maharashtra coast and analyzed for the associated bacteria. Place and Duration of Study: Seaweed samples analyzed in this study were from Kelwa, Manori and Ratnagiri along the Maharashtra coast. The analysis was performed during June to September 2021. Methodology: Bacteria from freshly collected seaweed samples were homogenized in saline, 10-fold serially diluted and plated on Zobell marine agar. Distinct colonies were selected and identified by a series of biochemical tests, followed by partial 16SrRNA gene sequencing. The physiological characteristics of the isolated bacteria were studied by screening for temperature and salinity tolerance, production of protease, lipase, agarose, amylase and biosurfactants. Results: The total seaweed bacterial count ranged from 4.5 ×103 to 2.9 × 104 CFU/g. Seventy-seven bacteria were isolated, 44 (57.14%) and 33 (42.85%) isolates from green and brown seaweeds respectively. The 16SrRNA sequencing of 20 representative isolates revealed the dominance of Bacillus spp., followed by Vibrio spp. Growth at 0°C was exhibited by all bacteria except Bacillus tequilensis, Bacillus altitudinis, Oceanobacillus iheyensis and one isolate of Vibrio spp. A majority of the isolates grew at 45°C. Vibrio spp. exhibited protease, amylase, gelatinase, and agarase activities, whereas the biosurfactant activity was commonly associated with Bacillus spp. Conclusion: The results of this study illustrate the occurrence of seaweed-associated beneficial bacteria exhibiting bioactive properties with potential biomedical applications.

A Computer Vision Model for Seaweed Foreign Object Detection Using Deep Learning

Seaweed foreign object detection has become crucial for food consumption and industrial use. This process not only can prevent potential health issues, but also maintain the overall marketability of seaweed production in the food industry. Traditional methods of inspecting seaweed foreign objects heavily rely on human judgment, which deals with large volumes with diverse impurities and can be inconsistent and inefficient. An automation system for real-time seaweed foreign object detection in the inspection process should be adopted. However, automated seaweed foreign object detection has several challenges due to its dependency on visual input inspection, such as an uneven surface and undistinguishable impurities. In fact, limited access to advanced technologies and high-cost equipment would also influence visual input acquisition, thereby hindering the advancement of seaweed foreign object detection in this field. Therefore, we introduce a computer vision model utilizing a deep learning-based algorithm to detect seaweed impurities and classify the samples into ‘clean’ and ‘unclean’ categories. In this study, we managed to identify six types of seaweed impurities including sand sticks, shells, discolored seaweed, grass, worm shells, and mixed impurities. We collected 1204 images and our model’s performance was thoroughly evaluated based on comparisons with three pre-trained models, i.e., Yolov8, ResNet, and MobileNet. Our experiment shows that Yolov8 outperforms the other two models with an accuracy of 98.86%. This study also included the development of an Android application to validate the deep learning engine to ensure its optimal performance. Based on our experiments, the mobile application managed to classify 50 pieces of seaweed samples within 0.2 s each, showcasing its potential use in large-scale production lines and factories. This research demonstrates the impact of Artificial Intelligence on food safety by offering a scalable and efficient solution that can be deployed in other food production processes facing similar challenges. Our approach paves the way for broader industry adoption and advancements in automated foreign object detection systems by optimizing detection accuracy and speed.

Insights into PFAS contaminants before and after sewage discharges into a marine protected harbour

Per and polyfluoroalkyl substances (PFAS) and their degradation products are a concern to human and ecosystem health. Wastewater treatment plants are not efficient at removing PFAS compounds and are thought to be a major source of these compounds to marine environments. The sewerage infrastructure in the UK, has over 20,000 combined stormwater overflows (CSOs). These CSOs are relief values whereby untreated wastewater can discharge under permit from the Environment Agency with exceptional rain/snowfall conditions. CSOs discharged 3.6 million monitored hours of untreated wastewater into English rivers and coasts in 2023. Concerns have been raised about the proximity of these CSO discharges to highly protected marine habitats. This study is the first to determine that PFAS concentrations are elevated in a highly protected marine bay (Langstone Harbour, England) following recent sewage releases compared to an extended period without discharge. Analysis was carried out into a suite of 54 PFAS compounds of which only one (PFHpA) was detectable above LOD prior to discharges but 8 afterwards. These included banned PFOS (Linear and Branched 8.6 ng/L ∓ 0.90) and PFOA (2.9 ng/L ∓ 0.29) which were above annual average EQS for inland and ‘other’ surface waters. Most of the PFAS compounds detected doubled in concentration above LODs. These two-fold increases we discuss are likely conservative estimates based on the use of LODs and tidal conditions. Additional Oysters (Crassostrea gigas) and Seaweed (Fucus vesiculosus) were taken revealing high concentrations of the shorter chain PFBA (6.99μg/kg ∓ 2.42 ww) in seaweed samples. These seaweeds were calculated to have conservative bioaccumulation factors (BAF) > 6000 for PFBA indicating these algae might be an important reservoir of some PFAS contamination. We discuss these results in the context of the largescale discharges of untreated wastewater nationally and globally, and call upon a need for a better understanding of the transfer of PFAS contaminants into marine food chains.

Analysis of physicochemical, functional, and antioxidant properties of four different Indian seaweed species

The present study aims to elucidate the nutritional, functional, flow, and antioxidant properties of Ulva fasciata, Ulva lactuca, Chaetomorpha linum, and Gracilaria edulis. The highest percentage of protein (24.26 %) in U. fasciata; fat (6.33 %) and total carbohydrates (46.39 %) in C. linum; crude fibre (8.67 %) in U. lactuca; ash (22.45 %) content in G. edulis was observed among the four-seaweed. The highest oil absorption capacity was found for C. linum (1.59 %), followed by G. edulis (1.21 %), U. lactuca (1.04 %), and U. fasciata (0.91 %). The water absorption capacity in U. fasciata (4.55 %) was observed to be the highest followed by C. linum (3.84 %), U. lactuca (3.78 %), and G. edulis (2.22 %). U. fasciata exhibited the highest solubility (35.83 ± 1.97 %) and emulsifying capacity (99.00 ± 0.00 %), while G. edulis showed the highest foaming capacity (75.00 ± 1.00 %). The angle of repose of G. edulis and C. linum powder showed excellent flowability than U. lactuca and U. fasciata. Carr's index and Hausner ratio showed that all seaweed samples were free-flowability, except for G. edulis and C. linum. The bulk density (0.71 g/cm3) and tapped density (0.85 g/cm3) of U. fasciata were observed to be the highest, whereas true density (1.11 g/cm3) was recorded highest in U. lactuca. The most increased antioxidant activity was found in G. edulis (65.90 %) followed by C. linum (53.01 %), U. lactuca (51.76 %), and U. fasciata (43.56 %). The total phenolic content (10.93 mg GAE/g) and flavonoid content (1.71 mg QE/g) were higher in U. fasciata. FTIR analysis detected the presence of amide, amino, hydroxyl, ester groups and it can conclude the presence of essential components such as proteins, amino acids, polysaccharides, and fat. Thus, the selected four marine seaweeds act as a good source of functional components and can be utilized for the development of functional food products such as bread, biscuits, cookies, tea, snacks, soups and beverages.

Sensory and consumer aspects of sea lettuce (Ulva fenestrata) – impact of harvest time, cultivation conditions and protein level

The green seaweed Ulva fenestrata is a future food candidate, however, both compositional, e.g. protein content, and sensory qualities depend on cultivation and harvest conditions. The aim was to explore sensory qualities of, and consumer attitudes to, U. fenestrata derived from three different cultivation conditions and three harvest times. U. fenestrata was cultivated at sea and in two different land-based tank settings, one mimicking seawater and one with added process water from fishing industry to increase protein content. The seaweed was subjected to sensory analysis performed by an analytical sensory panel and a focus group consisting of consumers. The former assessed the seaweed as dried whole blades (9 samples) and as emulsions (9 samples). Consumers assessed whole blades and a vegan spread enriched with powdered U. fenstrata. All seaweed samples were intensely green; had tastes of umami, salt, bitter, and sour; odours and flavours of grass and fresh seaweed; and had a crispy texture. Cultivation in tanks resulted in a crispier texture than sea cultivation (p<0.001). Protein content increased from 14.4% to 21.6% in tank cultivation with process waters, which increased green colour intensity (p<0.007) and decreased intensity of bitterness (p<0.001). Overall, consumers were positive towards seaweeds as foods.

Epiphytic microbiome associated with intertidal seaweeds in the Mediterranean Sea: comparative analysis of bacterial communities across seaweed phyla

The complex interactions between epiphytic bacteria and marine macroalgae are still poorly understood, with limited knowledge about their community structure, interactions, and functions. This study focuses on comparing epiphytic prokaryotes community structure between three seaweed phyla; Chlorophyta, Rhodophyta, and Heterokontophyta in an easternmost rocky intertidal site of the Mediterranean Sea. By taking a snapshot approach and simultaneously collecting seaweed samples from the same habitat, we minimize environmental variations that could affect epiphytic bacterial assembly, thereby emphasizing host specificity. Through 16S rRNA gene amplicon sequencing, we identified that the microbial community composition was more similar within the same seaweed phylum host compared to seaweed host from other phyla. Furthermore, exclusive Amplicon Sequence Variants (ASVs) were identified for each algal phyla despite sharing higher taxonomic classifications across the other phyla. Analysis of niche breadth indices uncovers distinctive affinities and potential specialization among seaweed host phyla, with 39% of all ASVs identified as phylum specialists and 13% as generalists. Using taxonomy function prediction, we observed that the taxonomic variability does not significantly impact functional redundancy, suggesting resilience to disturbance. The study concludes that epiphytic bacteria composition is connected to host taxonomy, possibly influenced by shared morphological and chemical traits among genetically related hosts, implying a potential coevolutionary relationship between specific bacteria and their host seaweeds.

Deciphering the Environmental Code: SEM-EDX Analysis of Lead and Mercury Distribution in Enhalus Acoroides From Kayeli Bay, Indonesia

Background: Illegal gold mining activities around Kayeli Bay have led to increased heavy metal contamination that has the potential to impair water quality and growth of Enhalus acoroides, an important seaweed species. This study aimed to investigate the distribution and concentration of heavy metals Pb and Hg in Enhalus acoroides organs (roots, rhizomes, and leaves) using SEM-EDX techniques and evaluate the impact of mining activities on the surface microstructure of these organs. Methods: Enhalus acoroides samples were collected from ten sampling points in Kayeli Bay, which were selected based on potential heavy metal contamination. SEM-EDX analysis was performed to assess the surface microstructure and distribution of heavy metals in the seaweed samples. Results: Results showed significant differences in Pb and Hg concentrations among samples from different locations, with Hg content consistently higher than Pb. Surface microstructure analysis showed morphological changes in roots, rhizomes, and leaves exposed to heavy metals, indicating environmental stress in Enhalus acoroides. Conclusion: This study confirmed the negative impact of heavy metal contamination on Enhalus acoroides in Kayeli Bay due to illegal gold mining activities. High concentrations of heavy metals, especially Hg, in seaweed organs indicate potential risks to marine ecosystem health and the sustainability of fisheries resources. These findings emphasize the need for stricter environmental monitoring and management to protect this important marine habitat from heavy metal pollution.

Heavy metal and mineral analysis of cultivated seaweeds from Cox’s Bazar Coast, Bay of Bengal, Bangladesh: a human health risk implication

Seaweeds are grown for their use in food and other sectors, however heavy metals (HMs) contamination raises serious issues for the environment and public health. This study focuses on seaweed samples (Hypnea musciformes and Gracilaria lemaneiformis) collected from the Rezu Khal seaweed culture site, Cox’s Bazar coast, Bangladesh. HMs and minerals were determined using Atomic Absorption Spectrophotometry (AAS). Among the elements examined, H. musciformes displayed the highest mean concentrations of minerals and HMs, including Magnesium (Mg) (8663.00 ± 2302.06 mg/kg), Copper (Cu) (10.59 ± 1.61 mg/kg), Iron (Fe) (7566.29 ± 2842.47 mg/kg), Manganese (Mn) (9.93 ± 2.88 mg/kg), Zinc (Zn) (29.54 ± 7.51 mg/kg), and Nickel (Ni) (11.77 ± 2.63 mg/kg). Conversely, G. lemaneiformis exhibited the highest levels of Calcium (Ca) (798.14 ± 143.40 mg/kg), Lead (Pb) (3.91 ± 1.74 mg/kg), and Chromium (Cr) (0.59 ± 0.30 mg/kg). Specifically, Mg was prominently abundant in H. musciformes, while Cawas more prevalent in G. lemaneiformis. Both seaweed types contained Pb and Cr. None of the elements was significantly different between the species (p < 0.05). The consumers are not exposed to any carcinogenic or non-carcinogenic risks related to these concentrations, according to the evaluation of carcinogenic and non-carcinogenic risks.

A sensitive method for the determination of per- and polyfluoroalkyl substances in food and food contact material using high-performance liquid chromatography coupled with tandem mass spectrometry

Dietary intake is the major pathway of human exposure to per- and polyfluoroalkyl substances (PFAS). Due to their generally very low concentrations in food, especially for foods of plant origin, and their toxicological relevance, demand is growing for improved selective and sensitive analytical methods for the determination of PFAS in the lower ng/kg range. The relevance is pointed out due to the fact that the European Commission has published limits of quantification (LOQs) in the lower ng/kg range for different food matrices in Recommendation (EU) 2022/1431 on the monitoring of perfluoroalkyl substances in food. For example, LOQs of 2 ng/kg for perfluorooctanesulfonic acid (PFOS), 1 ng/kg for perfluorooctanoic acid (PFOA), 1 ng/kg for perfluorononanoic acid (PFNA) and 4 ng/kg for perfluorohexanesulfonic acid (PFHxS) in fruit, vegetables and baby foods are required. A new, very sensitive method is presented here for the determination of 22 PFAS in food and food contact materials. The method is based on liquid-solid extraction and automated clean-up using two solid phase extraction techniques. The analytes are separated and detected by HPLC-MS/MS. A limit of detection (LOD) of 0.33 ng/kg and an LOQ of 1.0 ng/kg are attained for plant foods such as fruits and vegetables as well as for milk and baby food. For foods of animal origin such as egg, meat, fish and paper-based food contact materials an LOD of 1.6 ng/kg as well as an LOQ of 5.0 ng/kg are attained. PFOS and PFOA were the most abundant compounds in the food samples with concentration as high as 1,051 ng/kg of PFOA in sea weed samples and 772 ng/kg of PFOS in eggs samples. In food contact material samples, higher levels were found with a maximum of 310,000 ng/kg PFHxA. In sum the presented method firstly allows determination of PFAS in a wide variety of foodstuffs and paper-based food contact materials at EU-required concentration ranges.

Facile Synthesis of Silver Nanoparticles From Sustainable Sargassum sp. Seaweed Material and Its Anti-inflammatory Application.

Background Sustainable and environmentally friendly methods of producing nanoparticles are now being investigated by scientists. Because there are so many marine renewable resources, scientists are focusing their attention on studying seagrass, seaweed, mangroves, marine macroalgae, and microalgae. An exciting new frontier in research involves the synthesis ofnanoparticles using extracts from seaweed. Seaweed extracts are utilized to synthesize silver nanoparticles (Ag NPs), which serve as both reducing and stabilizing agents. Seaweed extracts possess bioactive substances like proteins, polysaccharides, and polyphenols that enable them to effectively convert silver (Ag+) ions intoAg NPs.Ag NPs derived fromSargassum seaweed have played an essential role in improving the anti-inflammatory properties of seaweed extracts. This study aimed to investigate thebiosynthesis of Ag NPs fromSargassumseaweed and evaluate their anti-inflammatory properties. Materials and methods About 50 g of seaweed samples were mixed with 100 mL of distilled water and stirred for 24 hours. Additionally, 1.2g of silver nitrate (0.120 M) was dissolvedin 60 mL of distilled water to make a silver (Ag) solution. A 60 mL solution of silver nitrate (AgNO3) was mixed with a 40 mL solution of seaweed extract in water, and the mixture was stirred with a stirrer for 24 hours.A UV spectrophotometer was used to regularly monitor the reduction ofAg+ ions in the solution. Ag NPs were purified using a sequence of centrifugation steps with a duration of 10 minutes at a speed of 2500 revolutions per minute (rpm). To remove moisture from the water-suspended nanoparticles, they were vacuum-dried for 24 hours. Results The synthesis of Ag NPsfrom seaweed extract resulted in a noticeable change in the color of the mixture, which went from pale to brown. The alteration in color signifies the reduction of AgNO3 to Ag+ ions, facilitating the creation of Ag NPs. X-ray diffraction (XRD) measurement verified the remarkable crystallinity of the synthesized Ag NPs. Field emission scanning electron microscopy (FESEM) images indicated a spherical, homogeneous structure. The Ag NPs derived from seaweed exhibited significant anti-inflammatory characteristics. Conclusion Utilizing Sargassum sp. seaweed in the biological synthesis of Ag NPs shows promiseto develop nanomaterials that canexhibit anti-inflammatory effects. This technique has benefits, such as being environmentally friendly and cost-efficient. Additional research in this area is essential for effectively exploiting the potential of Ag NPs in anti-inflammatory activity.

Effects of Different Solvents on the Antioxidant Activity of Several Seaweed Species from Semporna, Sabah, Malaysia

Sabah is the main seaweed producer in Malaysia especially red seaweeds which are commercially cultivated for the production of food gum known as carrageenan. Seaweeds are also high in phytochemical such as antioxidant compounds. Three seaweeds species from the Semporna Seawater, Sabah, namely Kappaphycus alvarezii, Caulerpa lentillifera and Sargassum polycystum were chosen for this study for the analysis of their antioxidant activities. K. alvarezii species is commercially cultivated whereas the other two (C. lentillifera and S. polycystum) are wild species. All seaweeds species underwent drying process in a cabinet dryer prior to the analyses. Six types of solvents which were water, ethanol, methanol, chloroform, ethyl acetate and hexane were used for the extraction process. Every concentrated, extracted solutions were then measured for their antioxidant activities based on total phenolic content (TPC), diphenylpicrylhydrazyl (DPPH) radical scavenging activity, ferric reducing antioxidant power (FRAP) and β-carotene bleaching assay. Results showed that TPC of S. polycystum was significantly higher (p&lt;0.05) than K. alvarezii but not significantly different (P&gt;0.05) from C. lentillifera. Even though the extraction yield of water was the highest, but the greatest antioxidant activity values were seen in methanolic extraction in comparison to the other solvents in TPC, DPPH and FRAP. This indicated that most of the antioxidant compounds in all the three seaweed samples are polar. However, high antioxidant activity in terms of β-carotene bleaching assay were seen in other solvent extractions, which were chloroform, hexane and ethyl acetate. This indicated that seaweed also contain non-polar antioxidant compounds such as β-carotene. Overall, the best extraction method of antioxidant compounds in seaweed samples was using methanol as the extractant.

Phylogenomic analysis of metagenome-assembled genomes indicates new taxa in the order Spirochaetales and proposal of Thalassospirochaeta sargassi gen. nov. sp. nov. from seaweeds

Six metagenome-assembled genomes (JB008Ts, JB007, JB015, JB003, JB004, and JB002) belonging to the order Spirochaetales were generated from seaweed samples collected from the Gulf of Mannar, India. The binned genomes JB008Ts and JB007 shared highest 16S rRNA gene identity of 94.9 % and 92.2–93.4 %, respectively with uncultivated Spirochaetaceae family members, and < 90 % identity with Marispirochaeta aestuari JC444T. While, the bin JB015 showed 99.1 % identity with Pleomorphochaeta naphthae SEBR 4209T. The phylogenomic and 16S rRNA gene-based phylogenetic analysis of the binned genomes JB007 and JB008Ts confirmed that these members belong to the family Spirochaetaceae and bins JB015, JB002, JB003, and JB004 belong to the genus Pleomorphochaeta within the family Sphaerochaetaceae. The AAI values of the binned genomes JB007 and JB008Ts compared to other members of the Spirochaetaceae family were between 53.9- 56.8 % and 53.8–57.1 %, respectively. Furthermore, the comparison of ANI, dDDH, and POCP metrics of the binned genomes JB007 and JB008Ts, both among themselves and with the members of Spirochaetaceae, was also below the suggested thresholds for genera delineation. Consequently, the binned genome JB008Ts is proposed as a new genus according to the guidelines of code of nomenclature of prokaryotes described from sequence data (SeqCode) with the name Thalassospirochaeta sargassi gen. nov. sp. nov., in the family Spirochaetaceae while the bin JB007 could not be proposed as novel taxa due to low-quality estimates. The bin JB015 and its additional genomes form a distinct clade, but their taxonomic status remains ambiguous due to the absence of genomic evidence from other Pleomorphochaeta members.

Microbacterium aquilitoris sp. nov. and Microbacterium gwkjiense sp. nov., isolated from beach.

Three Gram-reaction-positive bacterial strains, designated KSW-18T, KSW2-22, and KSW4-11T, were isolated from seawater, and two dried seaweed samples collected at Gwakji Beach in Jeju, Republic of Korea, respectively, and their taxonomic positions were examined by a polyphasic approach. The 16S rRNA gene phylogeny showed that strain KSW4-11T was tightly associated with Microbacterium oleivorans NBRC 103075T, while strains KSW-18T and KSW2-22 formed a distinctive subline at the base of a clade including the above two strains. The three isolates showed high sequence similarity with one another (99.7-99.9%; 1-4 nt differences) and Microbacterium oleivorans (99.8-99.9%; 1-3 nt differences). The chemotaxonomic features were typical for the genus Microbacterium; Lysine as the diagnostic diamino acid and N-glycolylated muramic acid of the peptidoglycans, the predominant menaquinones of MK-11, MK-10 and MK-12, the major fatty acids of anteiso-C15:0 and anteiso-C17:0, and the major polar lipids including diphosphatidylglycerol, phosphatidylglycerol, and two or three unidentified glycolipids. In core genome-based phylogenetic tree, strains KSW-18T and KSW2-22 were closely associated with Microbacterium oleivorans NBRC 103075T, while strain KSW4-11T formed a distinctive subline at the base of a clade including the above three strains, in contrast to the 16S rRNA gene tree. Strains KSW-18T and KSW2-22 shared an OrthoANIu of 98.6% and a digital DNA-DNA hybridization of 87.6% with each other, representing that they were strains of a species, while the OrthoANIu and digital DNA-DNA hybridization values between strains KSW-18T and KSW4-11T, and between both of these isolates and all members of the genus Microbacterium were ≤86.5% and ≤30.7%, respectively. The analyses of overall genomic relatedness indices and phenotypic distinctness support that the three isolates represent two new species of the genus Microbacterium. Based on the results obtained here, Microbacterium aquilitoris sp. nov. (type strain KSW-18T = KCTC 49623T = NBRC 115222T) and Microbacterium gwkjiense sp. nov. (type strain KSW4-11T = KACC 23321T = DSM 116380T) are proposed.

Optimization of PCR Analysis Based on Start Codon Targeted Markers (SCoT Markers) for Identification of Genetic Variation of Seaweed from Central Sulawesi

Seaweed is a fishery commodity that has high economic value because it contains carrageenan which can be used in the pharmaceutical, food, cosmetics, and industrial fields. Central Sulawesi Province is the second largest seaweed producer in Indonesia after South Sulawesi Province. The genetic diversity of seaweed in Central Sulawesi has not been studied much. Therefore, molecular-based characterization activities to identify the genetic variation of seaweed in the province are urgently needed. The purpose of the study was to optimize PCR techniques based on targeted start codon markers (SCoT markers) to identify the genetic diversity of seaweed accessions from Central Sulawesi Province. The results showed that the parameters for seaweed PCR amplification have been optimized. Of the fifteen SCoT primers, 10 of them can work to amplify seaweed DNA collected from several regions in Central Sulawesi. This is shown by the production of PCR result amplicons. PCR results also indicate polymorphism from the seaweed samples tested, although some seaweed samples have not been successfully amplified. The parameters of the PCR technique still need to be improved, especially the concentration of DNA prints, so that valid PCR results will be obtained for use in identifying seaweed genetic diversity.

The phytochemical constituent and antioxidant activity of Sea Weed Euchaema Cottonii

This study aimed to determine the phytochemical content and antioxidant activity of the red sea weed Euchaema cottonii. The phytochemical component of this seaweed can be used as an agent for enteric methane mitigation. The antioxidant can be used to reduce the reaction of free radicals when the animals are in heat stress conditions. The study presented used fresh and oven-dried E. cottonii. The methods of study started with the extracting process of two seaweed samples (fresh and sundried) using 3 types of solutions, namely water, hexane, and dichloromethane (DCM). The phytochemical content was analyzed using spektro-tanat, while antioxidant activity was determined using the DPPH test (1,1-diphenyl-2-picrilhidrazil). The result showed that the extract seaweed E. cottonii contained alkaloid, flavonoid, saponin, and steroid/triterpenoid. The seaweed did not contain tannin. The seaweed contains 0.249 to 2.430 mg TAE/gram of total phenolic. Based on the results of the antioxidant activity test using DPPH obtained extract seaweed E. cottonii is active as an antioxidant. The highest phytochemical and phenolic content resulted when the dried seaweed was extracted using the DCM. It is concluded that sea weed E. cottonii contains some phytochemicals and has an antioxidant activity.

Characterization of Red Seaweed Chondracanthus Chamissoi from the Coasts of Perú: Chemical Composition, Antioxidant Capacity and Functional Properties.

The present investigation finds that Chondracanthus chamissoi seaweed abounding in Peruvian coasts is characterized by its nutritional composition, total polyphenols, antioxidant capacity, and functional properties such as water-holding capacity (WHC), oil-holding capacity (OHC), and swelling capacity (SC). Boiling and steaming were applied before dehydration to evaluate the effect of these thermal treatments, keeping a control sample. The results indicated that the control dried seaweed sample presented 20.2 ± 0.16g/100g dw of proteins, 20.0 ± 0.61g/100g dw of ash, and 56.6 ± 0.08g/100g dw of total dietary fiber. In addition, the control sample presented 1.6 ± 0.07mg GAE/g of total polyphenol content and 2.4 ± 0.30 mM Trolox mg/g of antioxidant capacity. In boiling samples, the apparent nutrient retention factors for proteins, fat, and dietary fiber are 96, 47 and 74%, respectively. In the steaming sample, the values were 102, 29, and 92%. The boiling before dehydration causes a significant decrease (p < 0.05) in total polyphenols and increases carbohydrates. Steaming before dehydration, a significant (p < 0.05) increase occurs in carbohydrates without significantly altering the concentration of total polyphenols. Regarding the functional properties, C. chamissoi presents 17.6 ± 0.15g/g of WHC, 2.4 ± 0.78g/g of OHC, and 9.8 ± 0.75 mL/g of SC. Boiling produces an increase in WHC and OHC; steaming does not affect the properties of the control sample.C. chamissoi seaweed collected from the coasts of Perú is an excellent alternative for use as food and ingredients in processed foods for human consumption.

Utilizing fish wastewater in aquaponic systems to enhance anti-inflammatory and antioxidant bioactive compounds in Sarcodia suae

Aquaculture wastewater, rich in organic nutrients, is an essential environmental factor. When applied to seaweed cultivation systems, this wastewater holds the potential to notably increase the growth rate and carbon capture of Sarcodia suae. Sarcodia suae has the potential to be a healthy food due to its various biological activities; however, its chemical composition has yet to be completely defined. In this study, we applied a UHPLC-HRMS-based foodomics strategy to determine and classify possible bioactive metabolites in S. suae. From pooled seaweed samples (S. suae cultured in filtered running, FR, aquaponic recirculation, AR systems), we identified 179 and 146 compounds in POS and NEG modes, respectively. These compounds were then classified based on their structures using the Classyfire classification. Results show that S. suae in AR exhibited higher growth performance, and ten upregulated metabolites were determined. We also validated the anti-inflammatory and antioxidative bioactivities of some selected compounds. Our study provided important insights into the potential use of fish wastewater in aquaponic systems to profile and produce bioactive compounds in S. suae comprehensively. This has significant implications for the development of sustainable food and the promotion of environmental health.

Microplastic contamination in commercially packaged edible seaweeds and exposure of the ethnic minority and local population in Mexico

Diet is an important pathway for microplastic exposure. This study examined distinct edible seaweed products sold at ethnic food stores in Mexico for microplastic contamination, as well as the exposure of the Asian ethnic minority and local population to microplastics. Microplastics were extracted from seaweed samples using a wet oxide digestion with hydrogen peroxide followed by zinc chloride density separation. They were subsequently detected, quantified, and the polymer type was determined via microscopic inspection and Fourier transform infrared spectroscopy. Microplastic contamination was detected in all samples, with an average abundance of 24.0 ± 9.4 items g−1. Fibrous-shaped (61 %) and non-colored (57 %) microplastics were prevalent. Microplastics with sizes smaller than 0.2 mm prevailed (60 %), and they have the potential to penetrate gut barriers and endanger human health. Polymers identified consisted of polyethylene-polypropylene, polyamide, cellophane, rayon, and polyethylene terephthalate. According to pollution load index values, seaweed samples were minimally contaminated with microplastics, with values ranging between 3.7 and 6.0. The estimated yearly intake of microplastic from seaweed consumption by the South Korean and Chinese populations in Mexico was 5.8 × 104 ± 2.3 × 104 and 5.7 × 104 ± 4.9 × 104, respectively. This study's findings highlight the importance of improved control measures for minimizing microplastics in foods for export.