Search

MPs-oil composite pollutants interact with particles to form MPs-oil-particles aggregates (MOPAs) in nearshore environment. In this study, we investigated vertical transport and fate of MPs-oil composite pollutants mediated by particles under various time scales, proposed and elucidated associated mechanisms. Majority of MPs with -CH 2 suspended in water columns and particles with Si-O and O-H adsorbed MPs-oil composite pollutants in sediment phase, which caused differences in morphology structure and composition. The MOPAs with spherical or irregular three-dimensional in water columns can transport to sediment phase, resulting in more than 79 % lamellar MOPAs and more than 63 % oil in sediment phase. Besides, we demonstrated that degraded small-sized MPs-oil composite pollutants can resuspend into water columns. The mass of n-alkanes in sediment phase (< 45 μg) was lower than in water columns (< 120 μg) during degradation process. More importantly, during the intermediate stage of degradation, the size of oil droplets on surface of MPs decreased and particles trapped them to sediment phase, resulting in a V-shaped curve of mass changes of C 14 -C 35 in water columns. Our research fills the gap in the field of MPs-oil composite pollutants in water columns and sediment phase, which can provide theoretical support for their disposal., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Stress memory is an adaptive mechanism that enables organisms to develop resilience in response to environmental changes. Among them, somatic stress memory is an important means for organisms to cope with contemporary repeated stress, and is accompanied by transcription memory. Sulfide is a common environmental pollutant; however, some organisms have adapted to survive in sulfur-rich environments. Urechis unicinctus is a sulfur-tolerant organism that enhances sulfide stress tolerance by establishing a somatic sulfide stress memory mechanism. However, the molecular mechanisms that regulate sulfide stress memory remain unclear. To explore whether epigenetics, which plays a role in the response of organisms to environmental stress, is involved in regulating somatic sulfide stress memory, we performed a combined analysis of DNA methylation and transcriptome data. We found that elevated levels of DNA methylation under repetitive sulfide stress regulated gene expression and resulted in enhanced sulfide stress tolerance in U. unicinctus, a phenomenon verified using DNA methylase inhibitors. Transcriptional memory can be induced in genes related to oxidative stress, regulation of autophagy, and maintenance of protein homeostasis by altering the level of DNA methylation to facilitate sulfide stress acclimation. Our results provide new insights into adaptive mechanisms to cope with environmental fluctuations., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier B.V. All rights reserved.)

The emerging contaminants hexabromocyclododecanes (HBCDs) are proved to exhibit highly reproductive toxicity to marine rotifer Brachionus plicatilis, but how about the toxic differentiation among three diastereoisomers of HBCD, and what's the possible hidden mechanism? B. plicatilis was exposed to different concentrations of HBCD diastereoisomers, and the results showed that α-, β- and γ-HBCD exhibited various toxicity on it, the adverse effects on individual life history traits included shortened lifespan, shortened body length and reduced offspring number. Population dynamics analysis showed that the maximum population density and time to reach it were also significantly influenced. The integrated biomarker responses (IBR) were constructed based on key life history traits and population dynamics indicators, and the comprehensive toxicity ranking of HBCD diastereoisomers was β-HBCD> α-HBCD> γ-HBCD, which was consistent with acute experimental results. Results of transcriptome with emphasis on chemical defensome was conducted. Genes including cytochrome P450 enzymes (CYP450s), aldehyde dehydrogenases (ALDHs), glutathione S-transferases (GSTs) and SOD were upregulated under γ-HBCD compared to those under α- and β-HBCD. Results of molecular docking suggested γ-HBCD had stronger affinity with aryl hydrocarbon receptor (AhR) that made it more easily activate the subsequent components of the defending pathway. Moreover, transcriptome result showed the level of autophagy, the newly found protective pathway in B. plicatilis was higher under α- and β-HBCD than that under γ-HBCD and the TEM observation result provided the consist directly proof. The chemical defensome and the subsequently autophagy seemed to be the hidden mechanism for the toxicity differentiation of the HBCD diastereoisomers., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Reports a relationship with that includes:. Has patent pending to. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier B.V. All rights reserved.)

This study utilizes the Analytic Hierarchy Process (AHP) to prioritize climate change mitigation strategies for coastal regions systematically. The AHP, a robust data-driven decision-making framework, was employed to evaluate five strategies: Mangrove Restoration, Zoning and Building Codes, Seawalls, Coral Reef Protection, and Relocation Programs. The analysis revealed that Mangrove Restoration emerged as the most effective strategy, achieving the highest score of 0.65 due to its significant environmental impact and long-term sustainability. Zoning and Building Codes followed closely with a score of 0.58, showcasing their cost-effectiveness and regulatory advantages. While effective in urban areas, Seawalls ranked third with a score of 0.48, indicating limitations in social acceptance. Coral Reef Protection and Relocation Programs scored 0.46 and 0.38, respectively, reflecting their higher costs and resource intensity. The findings underscored the importance of prioritizing strategies that balance ecological health and socio-economic feasibility, offering actionable recommendations for policymakers and stakeholders. This research identifies key challenges such as balancing ecological health, socio-economic feasibility, and resource limitations. Our framework addresses these by integrating multi-criteria evaluation, presenting novel prioritization insights for climate adaptation strategies in coastal regions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Considering the limitations of human corneal endothelial cell proliferation as well as the severe shortage of corneal donations, it is imperative to develop improved methods of corneal endothelial cell transplantation. The purpose of this study was to construct a modified corneal endothelial cell transplantation approach using thermosensitive hydrogels combined with induced pluripotent stem cells (iPSCs)-derived human corneal endothelial cells (hCECs). In this study, thermosensitive hydrogels hydroxypropyl chitin/carboxymethyl chitosan (HPCH/CMCS) were fabricated, and their hydrogels properties and biocompatibility were investigated. Our results demonstrated that HPCH/CMCS hydrogels exhibited superior transparency, appropriate mechanical properties and favorable biocompatibility. A two-step induction method of small molecule compounds was employed, by which iPSCs were differentiated into hCECs via neural crest cells (NCCs). Additionally, a rabbit corneal endothelial dysfunction model was established in vivo, aiming to evaluate the safety and effectiveness of the combined method. Slit lamp microscope results indicated that significant transparency improvement could be noted in HPCH/CMCS/hCECs group (P = 0.006), whereas the corneal transparency was not homogeneous in different areas. Moreover, histological examinations and immunofluorescence analysis revealed that HPCH/CMCS/hCECs group showed a higher density of corneal endothelial cells and positive expressions of related markers. This study may provide ideas and experimental basis for the combined application of hydrogels and iPSC-derived corneal endothelial cells for corneal endothelial dysfunction. STATEMENT OF SIGNIFICANCE: Corneal transplantation is the most effective treatment for corneal endothelial dysfunction, which is challenged by issues such as corneal donor shortages and immune rejection. In this study, we proposed a combined transplantation method of cells and hydrogels for corneal endothelial dysfunction. We modified the protocols to obtain corneal endothelial cells from iPSCs by a two-step induction method. Besides, thermosensitive hydrogels with satisfactory biocompatibility and degradability were fabricated as fixation and support carriers of iPSC-derived corneal endothelial cells for in vivo transplantation. Experimental results demonstrated that this method could locally repair corneal endothelial dysfunction in rabbits, with the repaired corneas expressing relevant markers. This study presented a preliminary attempt to combine hydrogels and cells for corneal endothelial dysfunction., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Heat shock proteins (Hsps) are highly conserved molecular chaperones with essential roles against biotic and abiotic stressors. A large set of co-chaperons comprising J-domain proteins (DnaJs) regulate the ATPase cycle of Hsp70s with Hsp90s, together constituting a dynamic and functionally versatile network for protein folding/unfolding and regulation. Marine bivalves could accumulate and tolerate paralytic shellfish toxins (PSTs), the well-noted neurotoxins generated during harmful algal blooms. Here, 37 CfDnaJ and 35 PyDnaJ genes were systematically characterized in Zhikong scallop (Chlamys farreri) and Yesso scallop (Patinopecten yessoensis), the important aquaculture bivalve species in China. After exposure to different PST-producing dinoflagellates, Alexandrium minutum and Alexandrium catenella, diverse DnaJ regulations were presented in scallop hepatopancreas, accumulating incoming PSTs, and kidneys, transforming PSTs into higher toxic analogs. CfDnaJs' up-regulation in kidneys was similar with that in hepatopancreas, while their down-regulation was stronger in kidneys than in hepatopancreas, with CFA.38965.19.DNAJC30 being continuously down-regulated in both tissues of the two algae exposure. Moreover, PyDnaJs' up-regulation was only found in kidneys after A. catenella exposure, and PYE.10799.6.DNAJB1 was down-regulated in both tissues through the experiment. Together with the expression trends and correlation of DnaJ-Hsp70-Hsp90 genes, the organ-, toxin-, and species-dependent Hsp70B2 expressions were coordinately co-expressed with diverse DnaJ members, suggesting the functional diversity of scallop DnaJs with conserved Hsp70B2s in response to stress by PST-producing algae. Our results confirmed the regulated coordination of DnaJ-Hsp70B2 co-chaperons in scallops, and provided vital insights into the function and adaptation of scallop Hsps in response to PST stress., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 The Authors. Published by Elsevier Inc. All rights reserved.)

Across large oceanic spatial scales, the mechanisms governing microbial community composition remain poorly understood, particularly regarding the influence of biotic factors. In this study, samples were collected over a 3772.55-km transect in the Western Pacific surface waters, with 16S and 18S ribosomal RNA gene sequencing employed to elucidate the assembly processes and drivers of microbial communities. Both eukaryotic (EM) and prokaryotic microbial (PM) communities exhibited a significant distance-decay relationship throughout the survey, although their assembly mechanisms differed. Biotic factors played a pivotal role in shaping the biogeographical patterns of both EM and PM communities, indicating that cross-domain microbial interactions significantly affect each other's distribution. Furthermore, the stability of the co-occurrence network was more strongly influenced by cross-domain microbial relationships than by keystone taxa. These findings advance our understanding of the mechanisms and biogeographical patterns sustaining microbial diversity across large oceanic spatial scales., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Benthic diatoms serve as exemplary indicators for the assessment of ecological conditions in freshwater ecosystems. However, an approach to assessing and managing transitional water zones by benthic diatoms is relatively less. This study entailed a detailed analysis and comparison of the seasonal dynamics in species- and guild-based benthic diatom communities and their driving factors in a small-scale transitional water zone of the Yellow River Delta. Our findings revealed substantial seasonal variations in the composition and abundance of dominant species, as well as in the α and β diversity of the species-based community. Temperature emerged as the predominant environmental factor driving significant seasonal variations in the species-based community. However, no significant seasonal changes were observed in the composition and relative abundance of dominant guilds, as well as in the α, β, and functional diversity of the guild-based community. Redundancy analysis and Mantel tests demonstrated the guild-based community exhibited a stronger correlation with environmental factors compared to the species-based community. The guild-based community exhibited resilience to the influence of seasonal temperature fluctuations and exhibited a strong correlation with phosphate concentration variations. Our findings suggest that the guild-based community is a feasible approach to assessing ecological status across various seasons in the transitional water zone of the Yellow River Delta., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

The Sox family genes, as a group of transcription factors, are widely expressed in vertebrates and play a critical role in reproduction and development. The present study reported that 26 sox genes were identified from the genome and transcriptome of P. leopardus. The phylogenetic tree construction, chromosome localization, and gene structure analysis were executed to verify the evolutionary relationships, gene duplication, and deletion variations of P. leopardus sox genes in evolution. The sequence alignment revealed the HMG-box domain was highly conserved throughout the Sox gene family. The expression profile showed expression levels of sox genes showed tissue specificity. The dimorphic expression pattern of most sox genes in intersex and adult gonads was also observed, suggesting an important role of sox genes for sex differentiation in P. leopardus. Notably, sox32 was specifically highly expressed in gonadal tissues and might play a novel role within the gonads. The fluorescent in situ hybridization (FISH) showed sox32 mRNA was detected in germ stem cells and oocytes of different stages, and lowly expressed in sertoli cells. In testis, sox32 was not detected in male germ cells. Our results provided new insights into the sox32 that might be involved in gonadal development and differentiation in P. leopardus. To sum up, this study comprehensively analyzed the Sox gene family of P. leopardus and provided new insights into the function of sox genes, which could potentially revolutionize our understanding of the mechanisms of sex determination, sex differentiation, and reproductive development in fish., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Coastal bays link terrestrial and oceanic carbon reservoirs and play important roles in marine carbon cycles. Particulate organic carbon (POC) produced by phytoplankton is a major autochthonous carbon source in coastal bays. Previous studies on the fate of POC produced by phytoplankton mainly focused on the relationship between phytoplankton and zooplankton in classic food webs, while our knowledge on the roles of bacterioplankton is still limited, particularly in bays under highly intensive aquaculture activities. Here, we investigated bacterial community structure, and the influence of environmental factors and phytoplankton biomass and community structure based on samples collected in August 2022 from Sanggou Bay, a typical aquaculture bay in northern China. Environmental conditions, phytoplankton and bacterial community structure differed significantly between different aquaculture areas, showing higher relative abundance of Synechococcus sp. in the mixing area of shellfish and kelp culture (Area II) than the shellfish culture area (Area I). In contrast, Marivita cryptomonadis was more abundant in Area I, associated with elevated dissolved inorganic nitrogen (DIN), POC, POC/PN (the molar ratio of POC to particulate nitrogen) and sterol-derived total phytoplankton biomass. The strong correlation between total phytoplankton biomass and particle-associated bacteria indicated the important role of this bacterial fraction in processing organic compounds produced by phytoplankton. Significant correlations between bacterial community composition and POC/PN suggested more organic carbon potentially entering detrital biomass pools in Area I compared to Area II. Our results suggest that spatial distribution patterns of bacterial community structure were regulated by multiple abiotic and biotic factors and had a profound impact on the fate of organic carbon under highly intensive aquaculture activities in Sanggou Bay., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Residual concentrations of antibiotics in water can reach ng mL -1 - µg mL -1 levels, which pose high risks to crops during irrigation; however, the interactions between rice and antibiotics, as well as the defense mechanisms of rice at their early growth phase remain unclear. In this study, we investigated the uptake dynamics of a ubiquitously found antibiotic, ciprofloxacin (CIP) at 0.1, 1, 6.5, and 20 µg mL -1 in rice seedlings. We found gradually bioaccumulated CIP induced significant physiological changes including inhibited growth of roots and leaves of rice seedlings, and decreased pigment contents, which can be caused by disrupted homeostasis of reactive oxygen species. Integrating roots transcriptomics, metabolomics, and validation experiments, we found that rice seedlings synthesized more gibberellins to trigger the expression of transcription factors such as group VII ethylene response factors, which induced metabolic reprogramming to yield more fatty acids derivates. These compounds including eicosanoids, isoprenoids, and fatty acids and conjugates can act as signaling molecules, as well as antioxidants and energy sources to achieve rice recovery. This conclusion is supported by the evidence showing that adding gibberellins in rice seedlings culture decreased the accumulated CIP and improved rice growth; whilst, disrupting gibberellin signaling pathway using paclobutrazol as an inhibitor increased uptaken CIP in both roots and leaves with augmenting the antibiotic stress on rice. This study has demonstrated a gibberellin-based defense mechanism in rice for defense of CIP stress, which might have significant environmental applications since we can add minor gibberellins to reduce bioaccumulated CIP with simultaneously promoting rice growth at their early phases., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The contamination of Campylobacter in shellfish poses a health risk for its pathogenicity associated with campylobacteriosis. However, an efficient method to detect this risk is unavailable. Herein, we introduce a portable colorimetric biosensing platform that comprises three modules: an enrichment module 1, a binding and transduction module 2, and a smartphone-based module 3. Module 1 is an aptamer-modified 96-well plate for the specific capture of Campylobacter in a simple and high-throughput manner. Module 2 features a bifunctional biopolymer of L-glutamic acid γ-hydroxamate-alginate-Fe 3+ coordinating fusarinine C, which can bind the captured Campylobacter cells and transduce them into amplified color signals upon reaction with Fe 3+ -violurate complexes. Module 1 achieves a capture efficiency of 97.24 %, and the subsequent addition of module 2 renders colorimetric indication of Campylobacter ranging from 10 1 to 10 6 CFU/mL, achieving an actual limit of detection of 8 CFU/mL validated by Campylobacter single-cells. Moreover, the generated colors can be recognized and converted into cell densities by module 3 with ultrasensitivity. Notably, this biosensor-smartphone platform accomplishe reliable high-throughput colorimetric detection of Campylobacter in real samples with an accuracy of 80 %. This work showcases a proof of principle for efficient on-site detection of Campylobacter contamination regarding shellfish farming., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

UV-B radiation acts as an important environmental factor for aging micro-/nanoplastics (MNPs) in the marine environments, while the effect of aged MNPs on plankton is lacking specific research. Referencing to the UV-B radiation intensity in natural environments (2.29 W·m -2 ), we chose the floating polystyrene (PS) MNPs (50 nm, 1 µm) as the research target in this study. The results indicated that UV-B radiation aging for 30 days led to a rougher surface, increased S BET , increased hydrophobicity, and decreased negative charges of PS MNPs. Correspondingly, aged MNPs increased their adsorption abilities for 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), especially for the initial stage. After UV-B radiation aging processes, the individual toxicities of the two sized MNPs on Thalassiosira pseudonana and Brachionus plicatilis both increased, while their joint toxicities with BDE-47 decreased on T. pseudonana but increased on B. plicatilis. The changes in toxicity were more pronounced in 1 µm PS MNPs under air-aged conditions. This study provided the data basis for evaluating the changes of MNPs environmental behaviors under UV-B radiation in the marine environments, with important ecological significance., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Fucoidan, the main polysaccharide in various species of brown seaweed, has a high annual production. It is an important source of marine organic carbon and exhibits diverse biological activities and significant application potential. Rhodopirellula sp. P2, a novel marine bacterium of the phylum Planctomycetota, was isolated from intertidal algae samples collected from the Weihai coast, the Yellow Sea, China. The strain P2 is a Gram-negative, aerobic, and pear-shaped bacterium. Here, we report the complete genome sequence of Rhodopirellula sp. P2. The genome of strain P2 consists of a single circular chromosome with 7,291,416 bp and a GC content of 57.38 %, including 5462 protein-coding genes, 2 rRNA genes, and 48 tRNA genes. Genomic analysis revealed that strain P2 possessed 173 CAZymes and 106 sulfatases, indicating that strain P2 has the potential ability to utilize multiple polysaccharides, especially hydrolyze fucoidan to fucose. The genome of strain P2 also encodes a gene cluster related to bacterial microcompartment, suggesting the ability of strain P2 to metabolize fucose. These results enhance the understanding of the diversity and ecological functions of Planctomycetota, and also facilitate the exploitation of Planctomycetota and enzyme resources to utilize fucoidan. This study provides genetic insights into fucoidan catabolism by Planctomycetota, expanding our understanding of fucoidan-degrading microbial groups., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Bacteria of the genus Shewanella in the class Gammaproteobacteria are widely distributed in marine environments. Shewanella sp. H8, was isolated from a red algae sample collected from Nelson Island, Antarctica. Here, we present the complete genome sequence of strain H8, which consists of a single circular chromosome comprising 4,490,743 nucleotides with 40.59 % G + C content without any plasmid. In total, 3983 protein coding genes, 95 tRNA genes, and 25 rRNA genes were obtained. Genomic analysis of strain H8 showed that it contains four cold shock proteins and three fatty acid desaturases and possesses the potential to synthesize hglE-KS, arylpolyene, betalactone and RiPP-like compounds. Through genomic annotation, 91 protease-encoding genes were identified within the genome of strain H8. These proteases are classified into six categories based on their catalytic types. Among these proteases, metalloproteinases and serine proteases are dominant. These proteases may provide carbon and nitrogen sources to H8 by degrading proteins in the environment. This study will provide potential genetic information for the future research and development of cold-adapted proteases., Competing Interests: Declaration of competing interest The authors have no financial conflicts of interest to declare., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Endoscopic submucosal dissection (ESD) is an effective treatment for polyps and early gastrointestinal cancers, but requires a high level of operator skill. Injecting submucosal materials (SIM) helps create a fluid cushion between the mucosal and muscular layers, making the procedure easier and reducing associated risks. However, SIMs commonly used in current clinical practice tend to spread quickly and fail to provide long-lasting submucosal fluid cushions (SFC). Thus, there is a critical need for a material that is easy to inject while also maintaining a durable barrier. We prepared succinylated hydroxybutyl chitosan (HBC-SA) by adding succinic anhydride (SA) to hydroxybutyl chitosan (HBC). The hydrogel had excellent temperature-sensitive properties and was able to be injected via an endoscopic injection needle even after gel formation. In vitro and in vivo studies showed that it has satisfactory biocompatibility. Functional experiments showed that the submucosal lifting properties of this hydrogel were significantly better than that of normal saline (NS) and sodium hyaluronate (SH), two commonly used clinical materials. In addition, the hydrogel possessed excellent hemostatic properties. Based on these results, HBC-SA is a promising candidate for submucosal injection during ESD., Competing Interests: Declaration of competing interest The authors declare no competing financial interest., (Copyright © 2024. Published by Elsevier B.V.)

In recent years, microplastics have become a global environmental hot topic of concern. To explore the effects of different concentrations of microplastics on colonization dynamics of periphytic protozoan fauna, a 21-day study was conducted in temperature-controlled circulation systems. Periphytic protozoan communities were used as test organisms and exposed to five concentrations of MPs: 0, 1, 5, 25, and 125 mg l -1 , identification and enumeration were conducted on days 3, 5, 7, 10, 14 and 21. The results showed that the colonization dynamics were driven by MPs and significantly shifted at concentrations over 5 mg l -1 . However, a notable decline in maximum species richness and abundance was observed in the high concentrations of microplastic, along with significant deviations in colonization patterns from the control group (0 mg l -1 ). Therefore, it is suggested that the colonization dynamics of periphytic protozoa can serve as a bioindicator for assessing microplastic concentrations in marine environments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Ocean acidification is one of the major global environmental problems facing humankind today, and it has far-reaching impacts on marine organisms and the entire marine ecosystem. Zostera japonica, an important supporting species of intertidal seagrass beds, exhibits high photosynthetic productivity and plays an important role in the carbon cycle of nearshore waters. However, little is known about the characteristics, processes, and mechanisms of its response to ocean acidification. In this study, we conducted a 120-day acidification experiment in Z. japonica; here, plants underwent four leaf regeneration cycles to reveal the response mechanism of Z. japonica to ocean acidification (OA). We found that acidification significantly affected the seedling stage of Z. japonica, impacting leaf regeneration cycles by altering physiological and molecular responses. In one leaf regeneration cycle, the short-term exposure to CO 2 affected the seagrass parameters, such as the regulation of inorganic carbon uptake modes and the regulation of photosynthesis between the dark and light reactions, with the potential to affect the carbon sinks of the marine organisms. The long-term effects on the regulation of antioxidant enzymes and antioxidant metabolites, caused an improvement in the marine life adaptation to OA. In a comparison of the different leaf regeneration cycles, the response pattern of Z. japonica showed an offset of the acidification during the short cycles and an adaption to the acidification during the long cycles. This study revealed the response mechanism of Z. japonica to OA at different time scales and could provide a theoretical basis for accurately assessing the impact of OA on seagrass and the entire seagrass bed ecosystem., Competing Interests: Declaration of competing interest The authors declare no competing interest and no generative AI in scientific writing., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Heat shock proteins 70 KDa (Hsp70s) engage in a broad spectrum of cellular functions in response to various stressors. Marine bivalves face substantial threats from the rising seawater temperature attributed to global warming. In the present study, expression patterns of Hsp70s in Zhikong scallop Chlamys farreri (CfHsp70s) were determined in embryos and larvae at all developmental stages, in healthy adult tissues, and across four various tissues exposed to high temperature for acute and chronic periods through in silico analysis. Spatiotemporal expressions suggested CfHsp70s performed specific functional differentiations in scallop's development and growth. Regulatory expression patterns of CfHsp70s, characterized by predominant down-regulation in the mantle, gill and hemocytes, as well as contrasting up-regulation in the heart, suggest differential functional allocation of CfHsp70s among tissues in response to heat stress. Particularly, a core set of 14 CfHsp70s, especially the nine members of the Hsp70B2s, characterized by gene expansion, intron-less structure, shorter gene length, preference for hydrophilic amino acids, and coordinated expression profiles, was predominantly responsible for the inducible up-regulations observed across all four tissue types. Collectively, the tissue-specific, temporal and core gene-dependent expression patterns of CfHsp70s illustrate the functional allocation and molecular evolution of Hsp70 family members in Zhikong scallops., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Rising ocean temperatures due to global warming pose a significant threat to the bay scallop aquaculture industry. Understanding the mechanisms of thermotolerance in bay scallops is crucial for developing thermotolerant breeds. Our prior research identified Arg0230340.1, part of the positive cofactor 4 (PC4) family, as a key gene associated with the thermotolerance index Arrhenius break temperature (ABT) in bay scallops. Further validation through RNA interference (RNAi) reinforced PC4's role in thermotolerance, offering a solid basis for investigating thermal response mechanisms in these scallops. In this study, we performed a comparative transcriptomic analysis on the temperature-sensitive hearts of bay scallops after siRNA-mediated RNAi targeting Arg0230340.1, to delve into the detailed molecular mechanism of PC4's participation in thermotolerance regulation. The analysis revealed that silencing Arg0230340.1 significantly reduced the expression of mitochondrial tRNA and rRNA, potentially affecting mitochondrial function and the heart's blood supply capacity. Conversely, the up-regulation of genes involved in energy metabolism, RNA polymerase II (RNAPII)-mediated basal transcription, and aminoacyl-tRNA synthesis pathways points to an intrinsic protective response, providing energy and substrates for damage repair and maintenance of essential functions under stress. GO and KEGG enrichment analyses indicated that the up-regulated genes were primarily associated with energy metabolism and spliceosome pathways, likely contributing to myocardial remodeling post-Arg0230340.1 knockdown. Down-regulated genes were enriched in ion channel pathways, particularly those for Na + , K + , and Ca 2+ channels, whose dysfunction could disrupt normal myocardial bioelectric activity. The impaired cardiac performance resulting from RNAi targeting Arg0230340.1 reduced the cardiac workload in scallop hearts, thus affecting myocardial oxygen consumption and thermotolerance. We propose a hypothetical mechanism where PC4 down-regulation impairs cardiac bioelectric activity, leading to decreased thermotolerance in bay scallops, providing theoretical guidance for breeding thermotolerant scallop varieties and developing strategies for sustainable aquaculture in the face of long-term environmental changes., Competing Interests: Declaration of competing interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The pullulan synthetase gene (PUL1), involved in pullulan biosynthesis in Aureobasidium species, remains poorly understood. The open reading frame (ORF) of the PUL1 gene from the high pullulan-producing yeast Aureobasidium melanogenum P16 strain was cloned and characterized. The ORF of the PUL1 gene was determined to be 592 bp in length, encoding 178 amino acid residues. It was observed that an intron of 55 bp disrupted the gene. The promoter of the PUL1 gene contained a CAAT box, a TATA box, and a 5'-HGATAR-3' sequence. The deduced protein possessed a signal peptide comprising 18 amino acids and harbored five potential N-glycosylation sites. Following the disruption of the PUL1 gene in strain P16, the disruptant DP108 yielded 34.7 ± 0.3 g/L of pullulan from sucrose, significantly lower than the production by its wild-type strain P16. This discrepancy underscored the close association between the PUL1 gene and pullulan biosynthesis. The majority of the fused Gfp-Pul1 proteins were found to be localized in the cell membrane and on the surface of vacuoles within the yeast-like fungal cells, indicating that pullulan biosynthesis occurred at these subcellular sites. Following the overexpression of the PUL1 gene, strain G14 produced >72.0 g/L of pullulan from sucrose, surpassing the production of its wild-type counterpart strain P16, which yielded 65.5 g/L of pullulan under the identical conditions. This outcome demonstrated that the overexpression of the PUL1 gene significantly enhanced pullulan production. The apparent molecular mass of the purified pullulan increased to 4.4 × 10 5  Da. As an auxiliary protein, Pul1 was predicted to bind to AmAgs2, the key enzyme in pullulan biosynthesis, facilitating enhanced pullulan production., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The present study evaluated the potential application of free-living marine nematode assemblages as indicators in assessing environmental condition of Jiaozhou Bay (JB), China. Shannon-Wiener diversity (H'), functional trait indices (Index of Trophic Diversity, ITD and Maturity Index, MI) were utilized to rank the benthic habitat quality of the sampled stations. Most of the nematode genera/species belonged to c-p (colonizer-persister) class 2, indicating dominance of opportunistic nematodes and suggesting organic enrichment in the bay. Based on nematode indices, the ecological condition varied from bad to good. Ranking variations were observed among different indices, suggesting different sensitivity of nematode indices to different types of disturbance. Based on the final ecological quality assessment (EcoQ), most sampled stations were ranked as moderate (station J1 was ranked as poor). Nematode indices are more indicative of the influence of land based discharges. For a comprehensive assessment of benthic ecosystem, combined meiofauna and macrofaunal indicators were suggested., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Vreelandella sp. SM1641 was isolated from the hydrothermal vent sediment of the southwest Indian Ocean at a water depth of 2519 m. The complete genome sequence of strain SM1641 was analyzed to understand its metabolic capacities and biosynthesis potential of natural products in this study. The genome of strain SM1641 consists of a circular chromosome and two plasmids. The length of the circular chromosome was 4,731,121 bp with GC content of 54.46 mol%, and the length of plasmid A was 302,095 bp with GC content of 54.95 mol%, and the length of plasmid B was 8857 bp with GC content of 46.31 mol%. Genomic data showed that strain SM1641 had several gene clusters involved in the synthesis of exopolysaccharides (EPSs) and polyhydroxyalkanoates (PHAs) synthesis. SM1641 also has a variety of genes that respond to osmotic stress, heat shock, cold shock, oxidative stress, and heavy metal stress, which plays a critical role in bacterial adaptation to hydrothermal environments. Therefore, genome sequencing and data mining of strain SM1641 are helpful to further understand the molecular mechanism of Vreelandella adapting to the deep-sea hydrothermal environment, and provide a basis for further experimental exploration., Competing Interests: Declaration of competing interest The authors have no financial conflicts of interest to declare., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Alginate, mainly produced by brown algae, is an important polysaccharide that supports the growth of marine bacteria. Vreelandella sp. F11 is a Gram-negative and aerobic marine bacterium, which was isolated from the brown algae sample collected from the Weihai coast, the Yellow Sea, China. Here, we present the complete genome of strain F11 and its genomic characteristics to utilize alginate. The genome of strain F11 comprises one circular chromosome with 4,840,724 bp and a GC content of 55.04 %. Strain F11 could grow with alginate as the sole carbon source. Genomic analysis revealed that strain F11 contains a gene cluster, encoding the enzymes, transporters and a regulator protein involved in utilizing alginate. Gene annotations suggested that the alginate utilization system of strain F11 is similar to those in Vibrio strains. However, strain F11 does not contain homologs of known KdgF (a key enzyme involved in the metabolism of alginate monomer) and inner membrane transporters of alginate oligomer uptake. The result indicated that strain F11 contains novel KdgF and inner membrane transporter system, which warrants further investigation. These data suggested that Vreelandella strains play a role in alginate utilization in the ocean and lay a foundation for the application of Vreelandella in the conversion of brown algae., Competing Interests: Declaration of competing interest The authors have no financial conflicts of interest to declare., (Copyright © 2024. Published by Elsevier B.V.)

Marine bacteria play important roles in the degradation and recycling of algal polysaccharides. However, the marine bacteria involved in fucoidan degradation and their degradation pathways remain poorly understood. Here, we report the complete genome sequence of Isoptericola halotolerans SM2308, isolated from a brown algal sample collected from an intertidal zone of the Yellow Sea in China. The genome of strain SM2308 consists of a single circular chromosome of 4,011,455 bp with a high GC content of 72.70 %. Strain SM2308 exhibited rapid growth on fucoidan as the sole carbon source, indicating its capacity to degrade fucoidan. Gene annotation and metabolic pathway analyses showed that strain SM2308 possesses a complete pathway for utilizing fucoidan, including the extracellular breakdown of polymeric fucoidan into smaller fucooligosaccharides/fucose by fucoidanases, the transmembrane transport of fucooligosaccharides/fucose into the cytoplasm by an ABC transporter, and the intracellular fucose catabolism via a non-phosphorylative pathway. This represents the first genome of an actinobacterium from the order Micrococcales with fucoidan-degrading ability. The genome of Isoptericola halotolerans SM2308 provides insights into the role of actinobacteria in the biogeochemical cycling of fucoidan in marine ecosystems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Cephalopods occupy a mid-trophic level in marine ecosystems and are vital both ecologically and as fishery resources. However, under the pressure of climate change and fishing, the sustainability of cephalopod resources requires reasonable management. This study aims to study climate change and fishing impacts on the common economic cephalopod species habitats using species distribution models. We take the northwest Pacific Ocean region as an example, which stands out as a significant region for cephalopod production around the world. Results found that the habitats of cephalopods are moving to higher latitudes or deeper waters (Bohai Sea, mid-bottom Yellow Sea, and the Okinawa Trough waters) under climate change. Additionally, these regions are currently under lower fishing pressure, which suggests that species migration might mitigate the effects of warming and fishing. This study provides the large-scale assessment of the distribution range of cephalopods affected by climate change coping with fishing pressure in the northwest Pacific Ocean. By identifying climate refuges and key fishing grounds, we underscore the importance of this information for managing cephalopod resources in the context of climate adaptation and sustainable fishing practices., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Harmful algal blooms (HABs) increase with eutrophication depending on the nutrient structure (availability and ratios), but an unequivocal causal link between these factors is rarely established. Here, we provide support for the causal link between the nitrogen structure and physiological processes of Ulva prolifera as the causative species of Yellow Sea green tides (YSGTs) using in situ and laboratory experiments. The results showed that the components of nitrogen nutrients in seawater exhibited significant spatiotemporal variation. The concentration of NO 3 -N showed a notable decreasing trend from south to north. Sufficient dissolved inorganic nitrogen (DIN) induced increases in thalli nitrate reductase (NR) and glutamine synthetase (GS) activities. This could accelerate thalli uptake of nitrogen nutrients. The glutamate dehydrogenase (GDH) activity was significantly upregulated with the increasing proportion of dissolved organic nitrogen (DON) in seawater. The change in nitrogen structure regulated the activity of NR during the long-distance floating migration of the YSGTs. And the activity of NR could modulate the nitric oxide (NO) content in the thalli. NO was used as a signal molecule to enhance the antioxidant defense system of thalli. The efficient antioxidant system in the thalli could reduce oxidative stress and effectively maintain high photosynthetic activity. The findings deepen our understanding of the relationship between nitrogen structures and key biological processes in macroalgae. This study also suggest that NO can enhance key biological processes in U. prolifera under varying nitrogen structures.- -N showed a notable decreasing trend from south to north. Sufficient dissolved inorganic nitrogen (DIN) induced increases in thalli nitrate reductase (NR) and glutamine synthetase (GS) activities. This could accelerate thalli uptake of nitrogen nutrients. The glutamate dehydrogenase (GDH) activity was significantly upregulated with the increasing proportion of dissolved organic nitrogen (DON) in seawater. The change in nitrogen structure regulated the activity of NR during the long-distance floating migration of the YSGTs. And the activity of NR could modulate the nitric oxide (NO) content in the thalli. NO was used as a signal molecule to enhance the antioxidant defense system of thalli. The efficient antioxidant system in the thalli could reduce oxidative stress and effectively maintain high photosynthetic activity. The findings deepen our understanding of the relationship between nitrogen structures and key biological processes in macroalgae. This study also suggest that NO can enhance key biological processes in U. prolifera under varying nitrogen structures., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Coastal marine areas are frequently affected by human activities and face ecological and environmental threats, such as algal blooms and climate change. The community structure of phytoplankton-primary producers in marine ecosystems-is highly sensitive to environmental factors, such as temperature, salinity, and nutrients. However, traditional methods for exploring the relationship between phytoplankton communities and environmental factors in eutrophic marine areas are limited by various factors. Therefore, this study employed interpretable machine learning models, integrating high-dimensional data analysis and complex system modeling, to quantitatively and thoroughly analyze the dynamic relationship between phytoplankton communities and environmental variables in high-frequency samples collected over 53 weeks from eutrophic marine areas. The cell abundance of phytoplankton exhibited a distinct "two-peak pattern" variation. Interpretable machine learning model analysis revealed the dynamic contributions of different environmental factors during changes in the phytoplankton community structure. The results showed that temperature was a key environmental factor that affected phytoplankton growth during peak periods. In addition, the contribution of salinity increased during the second peak in phytoplankton abundance, highlighting its central role in the ecological dynamics of this phase. During green tide outbreaks, particularly in Area 01, the contributions of factors such as temperature and salinity increased, whereas those of phosphates and silicates decreased, indicating that green tide outbreaks substantially altered the nutritional dynamics of the ecosystem. Furthermore, different phytoplankton species, such as Skeletonema costatum, Thalassiosira spp., and Nitzschia spp., exhibit varying responses to environmental factors. Hence, the predictions made using random forest and generalized additive models for phytoplankton cell abundance in two marine areas revealed complex nonlinear relationships between environmental factors, such as temperature, salinity, and phytoplankton abundance., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Haizhou Bay, a semi-enclosed key aquaculture area in East China, has had relatively limited research focused on trace metals and perfluoroalkyl acids (PFAAs) in its biota. This study characterized the distribution, biomagnification and health risks of selected trace metals and PFAAs in various marine organisms from Haizhou Bay. Among the species examined, zinc (Zn) was the most prevalent metal, followed by copper (Cu) and chromium (Cr), whereas cadmium (Cd), total mercury (THg), and methylmercury (MeHg) contents were relatively low. Perfluorooctane sulfonate (PFOS) was the most abundant PFAA, followed by perfluorooctanoic acid (PFOA). The calculated trophic magnification factors (TMFs) were above one for Cr, THg, MeHg, and all PFAAs except perfluorobutanoic acid (PFBA) and perfluorotetradecanoic acid (PFTeDA). Across animal groups, gastropods exhibited relatively low levels of THg, MeHg, and perfluorosulfonic acids (∑PFSAs). By comparison, fish generally had lower levels of Cd and Cu compared to other animal groups, and demersal fish had significantly higher MeHg compared to gastropods. Certain organisms, such as cephalopods and shrimps, were found to pose potential health risks due to elevated levels of Cd, while levels of other studied metals, PFOS and PFOA generally appeared to be within safe limits for human consumption. Further research is needed to assess the sources and impacts of these and other contaminants., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Herbicide-induced phytoplankton inhibition threatens coastal biodiversity and ecosystem function. Although studies employing single-frequence exposure aid in understanding the phytoplankton community's responses to herbicides, it's difficult to objectively assess their response to cyclic herbicide inputs (long-term low-dose and short-term high-dose) in marine ecosystems. Here, we analyzed the concentration and distribution of herbicides in global coastal waters and simulated this cyclic process through a two-phase atrazine exposure mesocosm experiment and laboratory tests. The results indicated that, the herbicide concentrations (0.82 nmol L -1 , 95 % CI 0.55, 1.74) from May to August were significantly higher than that (0.14 nmol L -1 , 95 % CI 0.02, 0.38) in the remainder months, and highest concentrations typically emerged in summer; the changes in phytoplankton community composition under environmental concentrations of triazine herbicides could recover in the short term, but sustained inhibition of biomass was produced; the dominant populations were more likely to develop tolerance through preexposure and recover from subsequent impulse of atrazine, but this process was accompanied by the loss of rare groups and a decrease in biodiversity, meanwhile, affected the bacterial community in phycosphere. Consequently, we considered that the cyclic herbicide inputs may cause more detrimental effects than single-frequence exposure, potentially leading to a large-scale decline in coastal primary productivity., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

The impacts and toxicological mechanisms of microplastics (MPs) or heavy metals on aquatic ecosystems have been the subject of extensive research and initial understanding. However, the combined toxicity of co-pollutants on organisms and cumulative toxic effects along the food chain are still underexplored. In this study, the ciliate protozoan Paramecium caudatum and zebrafish Danio rerio were used to represent the microbial loop and the higher trophic level, respectively, to illustrate the progressive exposure of MPs and cadmium (Cd 2+ ). The findings indicate that MPs (ca. 1 ×10 5 items/L) containing with Cd 2+ (below 0.1 µg/L) could permeate the bodies of zebrafish through trophic levels after primary ingestion by ciliates. This could cause adverse effects on zebrafish, including alterations in bioindicators (total sugar, triglycerides, lactate, and glycogen) associated with metabolism, delayed hepatic development, disruption of intestinal microbiota, DNA damage, inflammatory responses, and abnormal cellular apoptosis. In addition, the potential risks associated with the transfer of composite pollutants through the microbial loop into traditional food chain were examined, offering novel insights on the evaluation of the ecological risks associated with MPs. As observed, understanding the bioaccumulation and toxic effects of combined pollutants in zebrafish holds crucial implications for food safety and human health., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Global warming has significantly impacted agriculture, particularly in animal husbandry and aquaculture industry. Rising ocean temperatures due to global warming are severely affecting shellfish production, necessitating an understanding of how shellfish cope with thermal stress. The mitogen-activated protein kinases (MAPK) signaling pathway plays a crucial role in cell growth, differentiation, adaptation to environmental stress, inflammatory response, and managing high temperature stress. To investigate the function of MAPKs in bay scallops, a comparative genomics and bioinformatics approach identified three MAPK genes: AiERK, Aip38, and AiJNK. Structural and phylogenetic analyses of these proteins were conducted to determine their evolutionary relationships. Spatiotemporal expression patterns were examined at different developmental stages and in various tissues of healthy adult scallops. Additionally, the expression regulation of these genes was studied in selected tissues (hemocyte, gill, heart, mantle) following exposure to high temperatures (32 °C) for different durations (0 h, 6 h, 12 h, 24 h, 3 d, 6 d, 10 d). The spatiotemporal expressions of AiMAPKs were ubiquitous, with significant increases in AiERK expression observed at the umbo larval stage (3.09-fold), while Aip38 and AiJNK were identified as potential maternal effect genes. In adult scallops, different gene expression patterns of AiMAPKs were observed across eight tissues, with high expressions in the foot and gill, and lower expressions in the striated muscle. Following high temperature stress, AiMAPKs expressions in the gill and mantle were mainly up-regulated, while in the hemocyte, they were primarily down-regulated. These findings indicate time- and tissue-dependent expression patterns with functional allocation in response to different thermal durations. This study enhances our understanding of the function and evolution of AiMAPKs genes in shellfish and provides a theoretical basis for elucidating the energy regulation mechanism of bay scallops in response to high temperature stress., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Scaffolds with multiphasic structures are considered to be superior for guided tissue regeneration. Two types of tilapia skin collagen gradient membranes (stepped gradient and linear gradient) with multiphasic structures were prepared by controlling the collagen concentrations and the freezing rates. The results revealed that collagen gradient membranes were more capable of guiding tissue regeneration compared to homogeneous membranes. These two gradient membranes featured a dense outer layer and a loose inner layer, with good mechanical properties as indicated by tensile strengths of more than 250 Kpa and porosities exceeding 85 %. Additionally, these membranes also showed good hydrophilicity and water absorption, with an inner layer contact angle of less than 91° and a water absorption ratio greater than 40 times. Furthermore, the multiphasic scaffolds were proved to be biocompatible by the acute toxicity assay, the intradermal irritation test and so on. Gradient membranes could effectively promote the adhesion and proliferation of fibroblasts and osteoblasts, through elevating the TGF-β/Smad signaling pathway by TGF-β and Smads, and activating the Wnt/β-catenin signaling pathway by LRP5 and β-catenin, similar to homogenous membranes. Therefore, collagen gradient membranes from tilapia skin show important application value in guiding tissue regeneration., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Phosphorus (P) is an essential nutrient driving algal growth in aquatic ecosystems. Dissolved inorganic and organic P (DIP and DOP) are the main components in the marine P pools and are closely related to harmful algal blooms. The dinoflagellate Akashiwo sanguinea is a cosmopolitan species which frequently causes dense blooms in estuaries and coasts worldwide, while the availability of P to A. sanguinea still remain unclear. Herein, the physiological and transcriptomic responses of A. sanguinea grown under P-deficient, DIP-replete and DOP-replete conditions were compared. P-deficient adversely suppressed the growth and photosynthesis of A. sanguinea, while genes associated with P transport, DOP utilization, sulfolipid synthesis, and energy production, were markedly elevated. Three forms of DOP, namely, glucose-6-phosphate (G-6-P), adenosine 5-triphosphate (ATP), and β-Glycerol phosphate (SG-P), supported A. sanguinea growth as efficiently as DIP (NaH 2 PO 4 ), and no significant difference was observed in biochemical compositions and photosynthesis of A. sanguinea between the DIP and DOP treatments. While the genes related to P transporter were markedly suppressed in DOP groups compared with the DIP group. Our results indicated that A. sanguinea is a good growth strategist under P-deficient/replete conditions, and this species had evolved a comprehensive strategy to cope with P deficiency, which might be a crucial factor driving bloom formation in a low inorganic P environment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The deep marine sediments represent a major repository of organic matter whilst hosting a great number of uncultivated microbes. Microbial metabolism plays a key role in the recycling of organic matter in the deep marine sediments. D-amino acids (DAAs) and DAA-containing muropeptides, an important group of organic matter in the deep marine sediments, are primarily derived from bacterial peptidoglycan decomposition. Archaea are abundant in the deep ocean microbiome, yet their role in DAA metabolism remains poorly studied. Here, we report bioinformatic investigation and enzymatic characterization of deep marine sedimentary archaea involved in DAA metabolism. Our analyses suggest that a variety of archaea, particularly the Candidatus Bathyarchaeota and the Candidatus Lokiarchaeaota, can metabolize DAAs. DAAs are converted into L-amino acids via amino acid racemases (Ala racemase, Asp racemase and broad substrate specificity amino acid racemase), and converted into α-keto acid via d-serine ammonia-lyase, whereas DAA-containing di-/tri-muropeptides can be hydrolyzed by peptidases (dipeptidase and D-aminopeptidase). Overall, this study reveals the identity and activity of deep marine sedimentary archaea involved in DAA metabolism, shedding light on the mineralization and biogeochemical cycling of DAAs in the deep marine sediments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

The distinctive environmental attributes of the Southern Ocean underscore the indispensability of microorganisms in this region. We analyzed 208 samples obtained from four separate layers (Surface, Deep Chlorophyll Maximum, Middle, and Bottom) in the neighboring seas of the Antarctic Peninsula and the Cosmonaut Sea to explore variations in microbial composition, interactions and community assembly processes. The results demonstrated noteworthy distinctions in alpha and beta diversity across diverse communities, with the increase in water depth, a gradual rise in community diversity was observed. In particular, the co-occurrence network analysis exposed pronounced microbial interactions within the same water mass, which are notably stronger than those observed between different water masses. Co-occurrence network complexity was higher in the surface water mass than in the bottom water mass. Yet, the surface water mass exhibited greater network stability. Moreover, in the phylogenetic-based β-nearest taxon distance analyses, deterministic processes were identified as the primary factors influencing community assembly in Antarctic microorganisms. This study contributes to exploring diversity and assembly processes under the complex hydrological conditions of Antarctica., Competing Interests: Declaration of competing interest The authors declare that they have no competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

This study aimed to elucidate the effects of coastal environmental stress on the composition of sediment bacterial communities and their cooccurrence patterns in fishing harbors around the Bohai Economic Circle, China. Compared with the natural sea area, fishing harbors contained higher levels of organic pollution (organic pollution index = 0.12 ± 0.026) and considerably reduced bacterial richness and evenness. The distributions of sediment microbial communities clustered along the pollutant concentration gradients across fishing harbors. Betaproteobacteria dominated (76%) organically polluted fishing harbors, which were mostly disturbed by anthropogenic activities. However, the harbors also revealed the absence of numerous pathogenic (Coxiella and Legionella) and photosynthetic (Synechococcus and Leptolyngbya) bacteria. Abundant genera, including Thiobacillus and Arenimonas, exhibited a positive correlation with total phosphorus and a negative correlation with total nitrogen in sediments. Meanwhile, Sulfurovum, Psychrobacter, and Woeseia showed the opposite trend. Pollutant accumulation and anthropogenic activities caused the decrease in the sediment microbial diversity and dispersal ability and promoted convergent evolution. Severely polluted harbors with simplified cooccurrence networks revealed the presence of destabilized microbial communities. In addition, the modularity of bacterial networks decreased with organic pollution. Our results provide important insights into the adjustment mechanism of microbial communities to community organization and functions under environmental pollution stress. Overall, this study enhanced our understanding of how microbial communities in coastal sediments adapted and survived amidst anthropogenic activities like oily effluent discharges from large ships, wash water, domestic sewage, garbage, and fisheries wastes. It also examined their resilience to future contamination., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Perfluoroalkyl substances (PFAS) are widely dispersed persistent organic pollutants (POPs) throughout marine ecosystems. Due to ban of traditional long-chain PFAS, the emerging short-chain ones showed increased environmental detection as substitutes. As the foundation of aquatic food webs, microalgae play a pivotal role in the stability of marine environments. However, the toxicity of those short-chain PFAS was lack of investigation. Therefore, we chose 4C PFAS perfluorobutanoic acid (PFBA) and the marine model diatom Thalassiosira pseudonana as research targets, comprehensively studied the toxicity of PFBA to T. pseudonana in terms of the population growth, photosynthetic physiology and oxidative stress. Our results characterized the inhibited growth, inhibited photosynthetic parameters, increased reactive oxygen species (ROS) levels and activated antioxidant system under PFBA exposure. Further transcriptome analysis revealed the underlying molecular mechanisms: photosynthetic genes were slightly down-regulated and the expression of oxidative stress-related genes was enhanced; significant up-regulation of genes related to the DNA excision repair and replication-coupled DNA repair pathways; the expression of carbon metabolisms-related genes was increased, including the Calvin cycle, glycolysis, pentose phosphate pathway, tricarboxylic acid (TCA) cycle and fatty acid biosynthesis, that could provide sufficient energy for the recovery processes of microalgal cells. This study elucidated the underlying toxic mechanisms of PFBA on phytoplankton, and provided novel insights for assessing the environmental risks of PFAS., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

C-glycosylated flavones (CGFs) are the main flavonoids in duckweed (Lemna turionifera), known for their diverse pharmacological activities and nutritional values. However, the molecular mechanisms underlying flavonoid metabolism in duckweed remain poorly understood. This study identified a P1-Like R2R3-MYB transcription factor, LtP1L, as a crucial regulator of CGF biosynthesis and transport in L. turionifera. Over-expression of LtP1L led to a six-fold increase in CGF levels, whereas the CRISPR-mediated knockdown of LtP1L caused a drastic 74.3 % decrease in CGF contents compared with the wild type. LtP1L specifically activated the expression of genes encoding key enzymes involved in the biosynthesis of CGFs, including flavanone 3'-hydroxylases (F3'H), flavanone 2-hydroxylases (F2H), and C-glycosyltransferase (CGT). Meanwhile, LtP1L activated genes associated with phenylalanine and phenylpropanoid biosynthesis pathways, such as 3-deoxy-7-phosphoheptulonate synthase (DHS), phenylalanine ammonia-lyase (PAL), cinnamate 4-hydroxylase (C4H), and 4-coumarate: CoA ligase (4CL), redirecting carbon metabolic flux towards flavonoid pathway at the early stages of phenylalanine synthesis. In addition, LtP1L directly bound to a novel AC-like cis-element in the promoter of a tonoplast-localized ATP-binding cassette (ABC) transporter LtABCC4 and activated its expression. Furthermore, the preference of LtABCC4 for isoorientin over orientin during vacuolar transport was evidenced by the significant reduction of isoorientin compared to orientin in the Ltabcc4 crispr lines. Altogether, LtP1L acts as a crucial transcriptional orchestrator in coordinating the biosynthesis and intracellular transport of CGFs in duckweed., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Acute hemorrhage is a major cause of death in many emergency cases. Although many hemostatic materials have been studied in recent years, it is still necessary to develop new hemostatic materials with remarkable efficiency, biosafety, convenient preparation, low cost, and good biodegradability. In this work, novel chitosan (CS)/β-glycerophosphate (β-GP) composite porous microsphere with a uniform size of 210.00 ± 2.14 μm was fabricated through water-in-water (W/W) emulsion via microencapsulation, which can avoid the use of toxic crosslink chemicals and organic solvents to achieve facile and efficient preparation of microspheres. β-GP could promote the formation of microspheres by enhancing the hydrogen-bonding interaction between CS chains, which contributed to the macro-porous structure. Owing to their large pore size (6.0 μm) and high specific surface area (37.8 m 2 /g), the CS/β-GP microspheres could absorb water quickly and adsorb protein, red blood cells, and platelets through electrostatic forces to promote blood coagulation. Furthermore, the CS/β-GP microspheres achieved a significantly shortened hemostatic time (45 s) and reduced blood loss (0.03 g) in a rat liver injury model. Rat tail amputation test also showed a satisfactory hemostatic effect. Overall, the green and porous CS/β-GP microspheres can be used as a facile and topical rapid hemostatic material., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The Yellow River Estuary (YRE) is one of highly remarkable regions profoundly impacted by human activities, with numerous oil platforms dispersed throughout. In this area, offshore oil exploitation may pose significant ecological risks. To comprehensively evaluate the quantitative impacts of oil field exploitation on the marine coastal ecosystem, this study investigated the occurrence, sources, and ecological risks associated with 16 polycyclic aromatic hydrocarbons (PAHs) in seawater and sediment near oil platforms in the YRE. We found that 1) The concentrations of PAHs decreased from the surface seawater to sediments; 2) The ecological risk level of PAHs in seawater exceeded that in sediments; 3) terrestrial sources (combustion), rather than offshore oil drilling activities, significantly influenced regional ecological risks through processes of atmospheric deposition and surface runoff. These findings provide essential data for future estuarine research efforts while supporting mitigation measures aimed at addressing marine environmental pollution related to oil production activities., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study analyzed the response of marine phytoplankton to environmental changes induced by mesoscale warm eddies through the lens of functional groups, highlighting the complex interactions within the ecosystem. It was found that warm eddies significantly affected phytoplankton distribution, with cell abundance in the center being only 75.60 cells/L, compared to 1095.00 cells/L in the periphery. Vertical transport within warm eddies altered light conditions, affecting photophilic diatoms more, while increased temperatures favored the growth of warm-water dinoflagellates. This study also emphasized that ocean currents were significant factors, showing correlations with various functional groups and playing a key role in material transport and phytoplankton distribution. Additionally, the distinct responses of different functional groups to temperature and salinity underscored their unique adaptations to environmental changes. In periods without warm eddies, phytoplankton primarily congregated in shallower water layers., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Nitrite exposure has become a significant concern in the aquaculture industry, posing a severe threat to aquatic animals such as shrimp. While studies have reported the adverse effects of nitrite on shrimp growth, the part played by the gut microbiota in shrimp mortality resulting from nitrite exposure is poorly understood. Here, the effects of nitrite on shrimp gut bacterial community were investigated using 16S rRNA amplicon sequencing, bacterial isolation, genomic analysis, and infection experiments. Compared to the control&#95;healthy group, changes in the bacterial composition of the nitrite&#95;dead group were associated with reduced abundance of specific beneficial bacteria and increased abundance of certain pathogenic bacteria. Notably, members of the Photobacterium genus were found to be significantly enriched in the nitrite&#95;dead group. Genomic analysis of a representative Photobacterium strain (LvS-8n3) revealed a variety of genes encoding bacterial toxins, including hemolysin, adhesin, and phospholipase. Furthermore, it was also found that LvS-8n3 exhibits strong pathogenicity, probably due to its high production of pathogenic factors and the ability to utilize nitrite for proliferation. Therefore, the proliferation of pathogenic Photobacterium species appears pivotal for driving shrimp mortality caused by nitrite exposure. These findings provide novel insights into the disease mechanism in shrimp under conditions of environmental change., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper, (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Triazine herbicides are widely used in agriculture and have become common pollutants in marine environments. However, the spatiotemporal distribution characteristics and water quality criteria (WQC) of triazine herbicides are still unclear. This study found that triazine herbicides had a high detection rate of 100 % in surface seawater of Laizhou Bay, China, with average concentrations of 217.61, 225.13, 21.97, and 1296.72 ng/L in March, May, August, and October, respectively. Moreover, estuaries were important sources, and especially the Yellow River estuary exhibited the highest concentrations of 16,115.86 ng/L in October. The 10 triazine herbicides were detected in the sediments of Laizhou Bay, with a concentration ranging from 0.14-1.68 μg/kg. Atrazine and prometryn accounted for 33.41 %-59.10 % and 28.93 %-50.06 % of the total triazine herbicides in the seawater, and prometryn had the highest proportion (63.50 %) in the sediments. Correlation analysis revealed that triazine herbicides led to the loss of plankton biodiversity, which further decreased the dissolved oxygen. In addition, this study collected 45 acute toxicity data and 22 chronic toxicity data of atrazine, 16 acute toxicity data of prometryn, and supplemented with toxicity experiments of prometryn on marine organisms. Based on the toxicity database, the WQCs of atrazine and prometryn were derived using species sensitivity distribution. The overall risk probability of atrazine and prometryn were both less than 1.75 % in the Laizhou Bay, indicating an acceptable risk. This study not only clarified the pollution status and ecological risk of triazine herbicides, but also provided scientific basis for their environmental management standards., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Hydrogels can possess desired biochemical and mechanical properties, excellent biocompatibility, satisfactory biodegradability, and biological capabilities that promote skin repair, making them ideal candidates for skin healing dressings. Polysaccharides, such as chitosan, hyaluronic acid and sodium alginate as well as proteins, including gelatin, collagen and fibroin proteins, are biological macromolecules celebrated for their biocompatibility and biodegradability, are at the forefront of innovative hydrogel dressing development. This work first summarizes the skin wound healing process and its influencing factors, and then systematically articulates the multifunctional roles of hydrogels based on biological macromolecules (polysaccharides and proteins) as dressing in addressing bacterial infection, hemorrhage and inflammation during wound healing. Furthermore, this review explores the potential of these hydrogels as vehicles for combination therapy, by incorporating growth factors or stem cells. Finally, the article offers insights into future directions of such hydrogels in wound repair field., Competing Interests: Declaration of competing interest The authors declared no potential conflicts of interest with respect to the research, author- ship, and/or publication of this article., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Phthalate esters (PAEs) are emerging hazardous and toxic chemicals that are extensively used as plasticizers or additives. Diethyl phthalate (DEP) and dimethyl phthalate (DMP), two kinds of PAEs, have been listed as the priority pollutants by many countries. PAE hydrolases are the most effective enzymes in PAE degradation, among which family IV esterases are predominate. However, only a few PAE hydrolases have been characterized, and as far as we know, no crystal structure of any PAE hydrolases of the family IV esterases is available to date. HylD1 is a PAE hydrolase of the family IV esterases, which can degrade DMP and DEP. Here, the recombinant HylD1 was characterized. HylD1 maintained a dimer in solution, and functioned under a relatively wide pH range. The crystal structures of HylD1 and its complex with monoethyl phthalate were solved. Residues involved in substrate binding were identified. The catalytic mechanism of HylD1 mediated by the catalytic triad Ser140-Asp231-His261 was further proposed. The hylD1 gene is widely distributed in different environments, suggesting its important role in PAEs degradation. This study provides a better understanding of PAEs hydrolysis, and lays out favorable bases for the rational design of highly-efficient PAEs degradation enzymes for industrial applications in future., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal, relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Offshore waters have a high incidence of oil pollution, which poses an elevated risk of ecological damage. The microbial community composition and metabolic mechanisms influenced by petroleum hydrocarbons vary across different marine regions. However, research on metabolic strategies for in-situ petroleum degradation and pollution adaptation remains in its nascent stages. This study combines metagenomic techniques with gas chromatography-mass spectrometry (GC-MS) analysis. The data show that the genera Pseudoalteromonas, Hellea, Lentisphaera, and Polaribacter exhibit significant oil-degradation capacity, and that the exertion of their degradation capacity is correlated with nutrient and oil pollution stimuli. Furthermore, tmoA, badA, phdF, nahAc, and fadA were found to be the key genes involved in the degradation of benzene, polycyclic aromatic hydrocarbons, and their intermediates. Key genes (INSR, SLC2A1, and ORC1) regulate microbial adaptation to oil-contaminated seawater, activating oil degradation processes. This process enhances the biological activity of microbial communities and accounts for the geographical variation in their compositional structure. Our results enrich the gene pool for oil pollution adaptation and degradation and provide an application basis for optimizing bioremediation intervention strategies., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Microplastics (MPs) are pervasive environmental contaminants that have infiltrated even the most remote ecosystems. Despite their widespread distribution, the transfer patterns and impacts of MPs in remote lakes remain poorly understood. This study aimed to address the knowledge gap regarding the pathways and consequences of MP pollution in these isolated environments. Focusing on Kyêbxang Co, a remote salt lake in Tibet, this study investigated the transfer patterns, sources and ecological impacts of MPs, providing insights into their mobility and fate in pristine ecosystems. Water, sediment and biota (brine shrimp) samples from Kyêbxang Co, collected during the summer of 2020, were analyzed using µ-Raman spectroscopy to determine MP abundances, polymer types and potential sources. Findings indicated significant MP contamination in all examined media, with concentrations highlighting the role of runoff in transporting MPs to remote locations. The majority of detected MPs were small fragments (<0.5 mm), constituting over 93 %, with polypropylene being the predominant polymer type. The presence of a halocline may slow the descent of MPs, potentially increasing the exposure and ingestion risk to brine shrimp. Despite the currently low ecological risk estimated for MPs, this study underscores the need for long-term monitoring and development of a comprehensive ecological risk assessment model for MPs., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Mangrove forests, a critical coastal ecosystem, face numerous anthropogenic threats, particularly from aquaculture activities. Despite the acknowledged significance of viruses in local and global biogeochemical cycles, there is limited knowledge regarding the community structure, genomic diversity, and ecological roles of viruses in mangrove forests ecosystems, especially regarding their responses to aquaculture. In this study, we identified 17,755 viral operational taxonomic units (vOTUs) from nine sediments viromes across three distinct ecological regions of the mangrove forests ecosystem: mangrove, bare flat, and aquaculture regions. Viral assemblages varied among three regions, and the pathogenic viruses associated with marine animals, such as the white spot syndrome virus (WSSV) from Nimaviridae, were identified in this study. The relative abundance of Nimaviridae in the bare flat region was higher than in other regions. Furthermore, viruses in distinct mangrove forests sediments regions have adapted to their environments by adopting distinct survival strategies and encoding various auxiliary metabolic genes involved in carbon metabolism and antibiotic resistance. These adaptations may have profound impacts on biogeochemical cycles. This study provides the first insights into the effects of vegetation cover and aquaculture on the community structure and ecological roles of viruses in mangrove forests sediments. These findings are crucial for understanding the risks posed by anthropogenic threats to mangrove forests ecosystems and informing effective management strategies., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Arsenic is a toxic element widely distributed in the Earth's crust and ranked as a class I human carcinogen. Microbial metabolism makes significant contributions to arsenic detoxification, migration and transformation. Nowadays, research on arsenic is primarily in areas affected by arsenic pollution associated with human health activities. However, the biogeochemical traits of arsenic in the global marine ecosystem remain to be explicated. In this study, we revealed that seawater environments were primarily governed by the process of arsenate reduction to arsenite, while arsenite methylation was predominant in marine sediments which may serve as significant sources of arsenic emission into the atmosphere. Significant disparities existed in the distribution patterns of the arsenic cycle between surface and deep seawaters at middle and low latitudes, whereas these situations tend to be similar in the Arctic and Antarctic oceans. Significant variations were also observed in the taxonomic diversity and core microbial community of arsenic cycling across different marine environments. Specifically, γ-proteobacteria played a pivotal role in the arsenic cycle in the whole marine environment. Temperature, dissolved oxygen and phosphate were the crucial factors that related to these differentiations in seawater environments. Overall, our study contributes to a deeper understanding of the marine arsenic cycle., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)