Marine Life Science & Technology最新文献

Metabolic interactions between microbiomes and algal hosts within the phycosphere of marine macroalgae are drawing increasing attention due to their roles in food webs, global nutrient cycles, industries, and their potential as food resources. However, these relations remain poorly understood. In this study, 43 marine macroalgae, including red, brown, and green algae, were collected from the coastal areas of Korea. We identified the bacterial communities within the loosely and tightly attached environments (LAEs and TAEs, respectively) of the phycosphere, along with those in the surrounding seawater, using 16S rRNA gene sequencing. β-Diversity analysis revealed significant differences between the bacterial communities among the three, with minimal variation related to sampling location or algal color. Indicator value analysis identified Pseudoalteromonas (in the LAE and TAE), Psychromonas (in the LAE), Marinomonas (in the LAE), and Litorimonas (in the TAE) as the dominant taxa in the phycosphere, in contrast to seawater. Network analysis suggested positive correlations among taxa within the same environments and negative correlations between those in the LAE and TAE, highlighting their distinct ecological conditions. Analysis using the Phylogenetic Investigation of Communities by Reconstruction of Unobserved States and Kyoto Encyclopedia of Genes and Genomes pathways revealed functional variations between the phycosphere- and seawater-residing microbes. The microbial taxa-function relationships were assessed through Spearman's rank-order correlation. Additionally, bacterial species belonging to the core taxa were isolated and their genomes sequenced. Their metabolic traits were analyzed via bioinformatics, recognizing key metabolic features essential for symbiotic interactions with algal hosts and survival within the phycosphere. The findings of this study advance our understanding of the marine algal phycosphere microbiome by detailing the metabolic characteristics of potential keystone species.

Supplementary information: The online version contains supplementary material available at 10.1007/s42995-025-00325-6.

The complex current systems of the Southern Ocean play a critical role in shaping the heterogeneity and distinctiveness of Antarctic habitats. Nonetheless, how Antarctic water masses influence ciliates, one of the most common groups of protozoa in polar regions, remains largely unknown. The present study investigated how the ciliate communities are affected by complex Southern Ocean currents by analyzing the diversity distributions, community assembly mechanisms, and co-occurrence networks of ciliates across three distinct water masses in the Scotia Sea. The findings reveal that the hydrography of the Scotia Sea significantly affects the spatial patterns of planktonic ciliates, primarily through the combination of temperature, salinity, and depth. In contract to surface waters (Antarctic Surface Water and Antarctic Circumpolar Current), ciliates inhabiting deep waters (Circumpolar Deep Water) exhibit stronger and more direct correlations with the environment parameters, alongside greater network stability. Community assembly in surface and deep-water masses is governed by stochastic and deterministic processes, respectively. Compared to other Antarctic regions documented in previous studies, the Scotia Sea demonstrated the lowest alpha diversity indices for ciliates while harboring the highest number of endemic species. A detailed re-evaluation of Antarctic ciliate community structure in the Antarctic from prior research offers valuable insights into how dynamic ocean currents shape the ecological dynamics of ciliate communities, thus providing a broader understanding of the environmental changes impacting polar marine ecosystems.

Supplementary information: The online version contains supplementary material available at 10.1007/s42995-025-00308-7.

Inflammation plays a crucial role in defending the host against pathogens and other harmful stimuli. However, uncontrolled acute inflammation has been implicated in a multitude of diseases, including those that affect aquatic animals. While the processes that initiate the inflammatory response are relatively well understood, the roles of lipids, their derivatives, and the mechanisms by which they contribute to alleviating acute inflammation remain less well characterized. In the present study, lipidomic analyses were performed to identify changes in lipid metabolism in the coelomocytes of the sea cucumber Apostichopus japonicus after infection with Vibrio splendidus. The omics data indicated significant increases in specific sterols, including desmosterol, 25-hydroxycholesterol, and 24,25-epoxycholesterol, during the late phase of the inflammatory response. The accumulation of these sterols was found to be responsible for the suppression of A. japonicus interleukin-17 (AjIL-17)-mediated inflammatory response. A subsequent biolayer interferometry assay revealed that A. japonicus liver X receptor (AjLXR) served as the downstream receptor of these sterols. The knockdown of AjLXR reversed the desmosterol-dependent suppression of AjIL-17 expression. Conversely, the activation of AjLXR by the synthetic agonist GW3965 inhibited the expression of AjIL-17 induced by infection with V. splendidus or stimulation with LPS. Moreover, AjLXR repressed AjIL-17 transcription by directly binding to the AjIL-17 promoter in a SUMOylation-independent manner. In conclusion, our findings highlight the crucial role of the sterols-LXR axis in mitigating IL-17-mediated acute inflammation, suggesting that targeting this axis could be a promising strategy for preventing and treating chronic inflammation-associated diseases.

Supplementary information: The online version contains supplementary material available at 10.1007/s42995-025-00322-9.

Ciliates in the order Metopida exhibit a global distribution and play essential roles as consumers of and common hosts to prokaryotes in both hypoxic and anoxic environments. Based on detailed morphological and morphometric data of Metopus es and Brachonella contorta, type species of two common and relatively species-rich metopid genera, we investigate the morphogenesis, and molecular phylogeny of each, and analyze the secondary structure of the V9 region of their 18S rRNA gene sequences. The new findings include: (1) These two species present two different stomatogenetic modes, which are stable within their respective genera and each can be regarded as a reliable generic feature for differentiation. (2) Both species share the same outcome regarding the parental oral apparatus, i.e., the old paroral membrane and adoral zone of membranelles are entirely reorganized in situ in the proter. (3) The paroral membrane is diplostichomonadal in the examined isolates, a feature which has long been overlooked and may be enigmatically present in other previously described populations. As concerns their phylogeny, the clear delineation of each species is supported by the high conservation of SSU rRNA gene sequences, and the close phylogenetic clustering, of different populations of each species from geographically distant localities. In agreement with previous phylogenetic studies, the MeBr clade (Metopus, including M. es and marine/brackish Metopus members, and all Brachonella species) is recovered repeatedly with moderate to high support.

Supplementary information: The online version contains supplementary material available at 10.1007/s42995-025-00309-6.

While Isochrysis zhanjiangensis, a marine microalga, has been widely adopted in aquaculture for its health-promoting properties, its potential as a functional food for human metabolic health remains unexplored. To bridge this gap, this study systematically evaluated the nutritional composition, biosafety, and therapeutic efficacy of I. zhanjiangensis against high-fat diet (HFD)-induced metabolic disorders in mice. Our results revealed that I. zhanjiangensis exhibits a desirable nutritional profile with no detectable toxicity, and its dietary supplementation significantly attenuated HFD-induced metabolic dysregulation. Gut microbiota profiling further demonstrated that I. zhanjiangensis supplementation restored microbial homeostasis, evidenced by mitigation of the elevated Firmicutes/Bacteroidota ratio and enrichment of beneficial genera including Muribaculum, Candidatus_Arthromitus, and Veillonella. Hepatic metabolomics identified key metabolites modulated by I. zhanjiangensis, such as N1-methyl-2-pyridone-5-carboxamide, N-acetyl-L-histidine, and eicosapentaenoic acid, which are mechanistically linked to lipid metabolism regulation. These findings not only position I. zhanjiangensis as a promising candidate for functional food development targeting HFD-induced metabolic dysregulation, but also highlight the untapped potential of aquaculture microalgae as sustainable resources for nutraceutical innovation.

Supplementary information: The online version contains supplementary material available at 10.1007/s42995-025-00320-x.

Ecological succession is vital for forecasting ecosystem responses to environmental changes and their future states. Zooplankton, a primary natural food source in aquaculture, plays a crucial role in maintaining ecosystem function. Thus, understanding how zooplankton communities respond to environmental changes is essential for economic and ecological outcomes. In this study, we examined three types of aquaculture ponds (crab, crayfish, and fish ponds) with over 10 years of history and analyzed 27 environmental factors potentially influencing zooplankton dynamics throughout the year. Our results showed that Rotifera was the most abundant group in all three pond types, followed by Protista, Cladocera, and Copepoda. The dominant species across different seasons and ponds were Polyarthra vulgaris, Anuraeopsis fissa, and Trichocerca pusilla. The alpha diversity of zooplankton was influenced by various environmental factors across different pond types, with significant effects of antibiotics observed only in the fish ponds. The temporal and spatial distributions of zooplankton communities varied significantly. Deterministic processes, driven primarily by temperature and ammonia nitrogen, were identified as the primary mechanisms influencing zooplankton community assembly in freshwater aquaculture ponds. These findings inform management practices aimed at regulating key environmental drivers and optimizing zooplankton dynamics, with implications for maintaining ecosystem stability and productivity and, ultimately, supporting sustainable aquaculture.

Supplementary information: The online version contains supplementary material available at 10.1007/s42995-025-00297-7.

Anammox and denitrification are key processes for nitrogen removal in lake sediments. However, how environmental changes mediate the community structure and functional genes of nitrogen removal bacteria in lakes remain unclear. Using metagenome and amplicon sequencing, we investigated the anammox and denitrifying bacteria and their nitrogen removing potentials in lakes experiencing significant spatiotemporal and environmental variations. The community structure of anammox and denitrifying bacteria exhibited stronger lake-wide spatial variations than that of seasonality, while only the denitrification-related functional genes showed substantial variations in both lakes. Anammox genes (e.g., hzsA/B/C and hdh) showed no significant spatial variations. However, the abundances of anammox and denitrifying genes were significantly higher in winter than in summer. The mesotrophic Lake Weishan demonstrated a greater capacity for complete denitrification in winter, while the eutrophic Lake Donghu exhibited a higher potential of anammox in summer. Differences in functional gene abundances between lakes were more pronounced than variations in phylogenetic diversity, indicating clear functional adaptations to local environments. The coupled nitrogen removal potentials also reflected ecological interactions among anammox and denitrifying genes. Importantly, anammox and denitrifying bacterial communities and their functional genes were primarily driven by dissolved organic carbon, total phosphorous and zinc (Zn). The dissimilarities of anammox and denitrifying bacterial communities increased with geographic distance, indicating a clear distance-decay effect. This study highlights the anammox and denitrifying bacteria and their nitrogen removal potentials in lake sediments that are mediated by both spatial and seasonal environmental changes.

Supplementary information: The online version contains supplementary material available at 10.1007/s42995-025-00310-z.

Seven previously unreported sesquiterpenes including three rare 5/5/6-fused tricyclic gymnomitrane-type sesquiterpenes (1-3), an ent-longipinane-type sesquiterpene (4), a cuparane-type sesquiterpene (5), and two chamigrane-type sesquiterpenes (6 and 7), along with a known chamigrane-type sesquiterpene xylariterpenoid C (8) were isolated from the hydrothermal vent sediment derived fungus Penicillium sp. JWM79-5-1. Their structures were identified on the basis of 1D and 2D NMR, in conjunction with Mosher's method, X-ray crystallography, and electronic circular dichroism (ECD). The antithrombotic activity of compounds 1-6 and 8 was evaluated in arachidonic acid (AA)-induced zebrafish thrombosis model in vivo. The results revealed compound 1 with potent antithrombotic activity in a concentration-dependent manner. Further, the pro-angiogenic activities of compounds 1-6 and 8 were evaluated in a transgenic zebrafish model that expresses vegfr2, the receptor for the angiogenic factor VEGF, tagged with the green fluorescence protein (vegfr2-GFP) through detecting the length of both intersegmental vessels (ISVs) and subintestinal veins (SIVs). The results revealed that compound 1 exhibited a potent antithrombotic activity while 3 revealed a potent pro-angiogenic activity. These findings strongly support drug development of these compounds in cardiovascular disease treatment.

Supplementary information: The online version contains supplementary material available at 10.1007/s42995-025-00303-y.