Spatial-temporal variations of kelp I contents in coastal waters of China before and after the Fukushima Daiichi Nuclear Power Plant accident.

Radioactive I isotope, as one of the main products of the nuclear fission process, can be applied to track radioactive substances in the environment. So far, limited studies have investigated the spatial-temporal distribution of I in marine ecosystems including the I isotope released via nuclear activities. This study reports the I concentrations of kelps collected from the shallow coastal Yellow Sea and East China Sea from 2009 to 2021.

Metagenomic analysis reveals the composition and sources of antibiotic resistance genes in coastal water ecosystems of the Yellow Sea and Yangtze River Delta.

The rapid development of coastal areas has raised concerns about marine environmental pollution. In this study, metagenomics was employed to investigate antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), and bacterial communities in the Yellow Sea and Yangtze River Delta in China. Multidrug resistance genes were the most abundant ARGs in these regions.

Co-Culturing Seaweed with Scallops Can Inhibit the Occurrence of by Increasing Dissolved Oxygen and pH.

Seaweeds are critically important for the maintenance of biodiversity in marine aquaculture ecosystems, as they can inhibit the growth of . Here, we determined the optimal environmental parameters for co-culturing green macroalgae () and red macroalgae () with Chinese scallop () by measuring dissolved oxygen (DO), pH, and the strength of inhibition under laboratory conditions and validating the effectiveness of this optimal co-culture system from the perspectives of nutrient levels, enzyme activities, and microbial diversity. The results show that co-culturing 30 g of seaweed and three scallops in 6 L of seawater with aeration in the dark (1.

Chromosome-level assembly and gene annotation of Kappaphycus striatus genome.

Kappaphycus striatus is one of the carrageenan-producing red algae, and found primarily in tropical and subtropical coastal regions. Its global distribution is mainly in the Philippines, Indonesia, and Malaysia, among other locations. Here, through the high-quality chromosome-level genome sequences and assembly with PacBio HiFi and Hi-C sequencing data, we assembled one genome with a total of 211.

Vanadium-Dependent Haloperoxidase Gene Evolution in Brown Algae: Evidence for Horizontal Gene Transfer.

Compared with green plants, brown algae are characterized by their ability to accumulate iodine, contributing to their ecological adaptability in high-iodide coastal environments. Vanadium-dependent haloperoxidase (V-HPO) is the key enzyme for iodine synthesis. Despite its significance, the evolutionary origin of V-HPO genes remains underexplored.

Fucoxanthin Alleviates Dextran Sulfate Sodium-Induced Colitis and Gut Microbiota Dysbiosis in Mice.

The purpose of this study was to evaluate the preventive role and underlying mechanisms of fucoxanthin (Fx) on dextran sulfate sodium (DSS)-induced colitis in mice. The present data demonstrated that oral administration of Fx (50 and 200 mg/kg body weight/day) for 36 days significantly alleviated the severity of colitis in DSS-treated mice, as evidenced by attenuating body weight loss, bloody stool, diarrhea, shortened colon length, colonic epithelium distortion, a thin mucus layer, goblet cell depletion, damaged crypts, and extensive infiltration of inflammatory cells in the colonic mucosa. Additionally, Fx notably relieved DSS-induced intestinal epithelial barrier dysfunction via maintaining the tight junction function and preventing excessive apoptosis of colonic epithelial cells.

Preparation of Multifunctional Seaweed Polysaccharides Derivatives Composite Hydrogel to Protect Ultraviolet B-Induced Photoaging In Vitro and In Vivo.

Seaweed polysaccharides can be used for protective skin photoaging which is caused by long-term exposure to ultraviolet B (UVB). In this study, a multifunctional composite hydrogel (FACP5) is prepared using sulfated galactofucan polysaccharides, alginate oligosaccharides as active ingredients, and polyacrylonitrile modified κ-Carrageenan as substrate. The properties of FACP5 show that it has good water retention, spreadability, and adhesion.

Isolation and characterization of glutathione S-transferase genes and their transcripts in Saccharina japonica (Laminariales, Phaeophyceae) during development and under abiotic stress.

Background: Glutathione S-transferase (GST) is a crucial enzyme for metabolism, detoxification, and stress resistance in organisms. Many GSTs have been identified in seaweeds, but the isolation and functional analysis of GSTs in Saccharina japonica have not been completed.

Result: In this study, a total of 32 SjGST genes, localized on 10 scaffolds and 6 contigs, were identified and categorized into three groups.

Characterization of Chlorophyll Fluorescence and Antioxidant Defense Parameters of Two Strains under Different Temperatures.

In this study, two strains-the wild type and a green-pigmented mutant-were cultured at three temperatures (8, 20, and 30 °C) for 7 days to explore their temperature tolerance using photosynthetic performance and antioxidant defense parameters. When the two strains of were separately cultured at 30 °C, the fast chlorophyll fluorescence intensity of the wild type decreased, whereas the green mutant showed no significant change. The decrease in the performance index on absorption basis value under heat stress was lower in the green mutant than in the wild type.

Novel Chitin Deacetylase from Highlights the Potential for Chitin Derivative Production.

β-Chitin is an important carbon fixation product of diatoms, and is the most abundant nitrogen-containing polysaccharide in the ocean. It has potential for widespread application, but the characterization of chitin-related enzymes from β-chitin producers has rarely been reported. In this study, a chitin deacetylase (TwCDA) was retrieved from the Marine Microbial Eukaryote Transcriptome Sequencing Project (MMETSP) database and was heterologously expressed in vitro for functional analysis.

Isolation and functional verification of an aspartate aminotransferase gene from Neoporphyra haitanensis.

Background: Neoporphyra haitanensis is a commercial laver species in China. Aspartic acid is an important flavor amino acid, and aspartate aminotransferase (AAT) is a crucial enzyme in its biosynthesis. In this study, we cloned one AAT gene (NhAAT) from the red alga N.

Characterization of a Marine Diatom Chitin Synthase Using a Combination of Meta-Omics, Genomics, and Heterologous Expression Approaches.

β-Chitin has important ecological and physiological roles and potential for widespread applications, but the characterization of chitin-related enzymes from β-chitin producers was rarely reported. Querying against the Oceans Gene Atlas, 4,939 chitin-related unique sequences from 12 Pfam accessions were found in Bacillariophyta metatranscriptomes. Putative chitin synthase (CHS) sequences are decreasingly present in Crustacea (39%), Stramenopiles (16%) and Insecta (14%) from the Marine Atlas of Oceans Unigenes version 1 Metatranscriptomes (MATOUv1+T) database.

Isolation, identification, and biochemical characterization of a novel bifunctional phosphomannomutase/phosphoglucomutase from the metagenome of the brown alga .

Macroalgae host diverse epiphytic bacterial communities with potential symbiotic roles including important roles influencing morphogenesis and growth of the host, nutrient exchange, and protection of the host from pathogens. Macroalgal cell wall structures, exudates, and intra-cellular environments possess numerous complex and valuable carbohydrates such as cellulose, hemi-cellulose, mannans, alginates, fucoidans, and laminarin. Bacterial colonizers of macroalgae are important carbon cyclers, acquiring nutrition from living macroalgae and also from decaying macroalgae.

Prediction of the dynamic distribution for Eucheuma denticulatum (Rhodophyta, Solieriaceae) under climate change in the Indo-Pacific Ocean.

Eucheuma is one of the most important commercial red seaweeds in Southeast Asia, and plays an important role in the global seaweed aquaculture. It is expected to exhibit great responses to ocean warming. Here, we used maximum entropy species distribution models (SDMs) to estimate the suitable habitat of Eucheuma denticulatum under present conditions, and to predict the future range dynamics under the four representative concentration pathway (RCP) scenarios.

The organellar genomes of Silvetia siliquosa (Fucales, Phaeophyceae) and comparative analyses of the brown algae.

The brown alga Silvetia siliquosa (Tseng et Chang) Serrão, Cho, Boo & Brawly is endemic to the Yellow-Bohai Sea and southwestern Korea. It is increasingly endangered due to habitat loss and excessive collection. Here, we sequenced the mitochondrial (mt) and chloroplast (cp) genomes of S.

The Cell Wall Polysaccharides Biosynthesis in Seaweeds: A Molecular Perspective.

Cell wall polysaccharides (CWPS) of seaweeds play crucial roles in mechanical shear resistance, cell-cell adhesion and the interactions with changeable marine environments. They have diverse applications in food, cosmetics, agriculture, pharmaceuticals and therapeutics. The recent boost of multi-omics sequence analysis has rapidly progressed the mining of presumed genes encoding enzymes involved in CWPS biosynthesis pathways.

Glutamate Dehydrogenase Functions in Glutamic Acid Metabolism and Stress Resistance in .

is an important laver species in China. Its quality traits are closely related to the content of glutamic acid. Glutamate dehydrogenase (GDH) is a crucial enzyme in the glutamic acid metabolism.

Molecular Mechanism of Anti-Inflammatory Activities of a Novel Sulfated Galactofucan from .

Seaweed of is the most abundantly cultured brown seaweed in the world, and has been consumed in the food industry due to its nutrition and the unique properties of its polysaccharides. In this study, fucoidan (LJNF3), purified from , was found to be a novel sulfated galactofucan, with the monosaccharide of only fucose and galactose in a ratio of 79.22:20.

Full-Length Transcriptome of as a Reference Resource and Mining of Chitin-Related Genes.

β-Chitin produced by diatoms is expected to have significant economic and ecological value due to its structure, which consists of parallel chains of chitin, its properties and the high abundance of diatoms. Nevertheless, few studies have functionally characterised chitin-related genes in diatoms owing to the lack of omics-based information. In this study, we first compared the chitin content of three representative species.

Climate-induced range shifts shaped the present and threaten the future genetic variability of a marine brown alga in the Northwest Pacific.

Glaciation-induced environmental changes during the last glacial maximum (LGM) have strongly influenced species' distributions and genetic diversity patterns in the northern high latitudes. However, these effects have seldom been assessed on sessile species in the Northwest Pacific. Herein, we chose the brown alga to test this hypothesis, by comparing present population genetic variability with inferred geographical range shifts from the LGM to the present, estimated with species distribution modelling (SDM).

MiR8181 is involved in the cell growth regulation of Saccharina japonica.

Aureochrome, a blue-light receptor specifically found in photosynthetic stramenopiles, plays an important role in algal growth and development. It holds a reversed effector-sensor topology for the reception of blue light, acting as a candidate of optogenetic tool in transcriptional regulation. However, the inner regulatory mechanism of aureochrome is still unclear.

Genome-wide identification of chitinase genes in Thalassiosira pseudonana and analysis of their expression under abiotic stresses.

Background: The nitrogen-containing polysaccharide chitin is the second most abundant biopolymer on earth and is found in the cell walls of diatoms, where it serves as a scaffold for biosilica deposition. Diatom chitin is an important source of carbon and nitrogen in the marine environment, but surprisingly little is known about basic chitinase metabolism in diatoms.

Results: Here, we identify and fully characterize 24 chitinase genes from the model centric diatom Thalassiosira pseudonana.

A Sulfated Polysaccharide from Suppresses LPS-Induced Inflammation Both in a Macrophage Cell Model via Blocking MAPK/NF-κB Signal Pathways In Vitro and a Zebrafish Model of Embryos and Larvae In Vivo.

Inflammation is a complicated host-protective response to stimuli and toxic conditions, and is considered as a double-edged sword. A sulfated polysaccharide (LJPS) with a sulfate content of 9.07% showed significant inhibitory effects against lipopolysaccharide (LPS)-induced inflammation in RAW 264.