This study explores the dynamics of protist communities in the northeastern East China Sea (ECS) focusing on their responses to changing water masses and oceanographic conditions during spring, summer, and autumn in 2023. Water masses were classified using K-means clustering based on physico-chemical parameters, revealing significant seasonal variation. Protist community spatial, temporal, and vertical distributions were analy...

While phytoplankton are a major component of coastal ecosystems and experience a wide range of oxygen conditions, the survival and physiological responses of common phytoplankton species under hypoxia remain insufficiently understood. To explore these effects, cell densities of the two dinoflagellate species Prorocentrum triestinum and Amphidinium carterae, and the two diatom species Cylindrotheca closterium and Chaetoceros cu...

Dinoflagellate harbors diverse associated bacterial communities (ABCs) that play crucial roles in host physiology and ecological interactions. Coolia malayensis is a benthic dinoflagellate distributed from temperate to tropical regions. Despite growing knowledge about the morphology, distribution, and toxicity of C. malayensis, little is known about its associated bacteria, particularly under changing environmental conditions....

While γ-aminobutyric acid (GABA) promotes nutrient accumulation in green microalgae, its effects on marine diatoms—critical aquaculture feed—remain understudied. Understanding the physiological response of diatoms to exogenous GABA is vital for optimizing high-quality feed production. In this study, we investigated the impact of GABA on diatom growth, photosynthetic performance, proximate composition (lipids, proteins, carbohy...

Zeaxanthin epoxidase (ZEP) plays a central role in carotenoid metabolism, but its evolution and function in red algae remain unclear. Here, we comprehensively identified ZEP homologs across red algal lineages through phylogenetic reconstruction, conserved motif analysis, structural comparison, and branch‑specific selection pressure analyses to uncover adaptive evolutionary patterns. The ZEP homolog from Pyropia haitanensis (Ph...

Prasiola japonica is a freshwater green alga distributed in Northeast Asia. This study investigated the effects of 70% ethanol extract of P. japonica (Pj-EE) under testosterone-induced hair loss conditions using C57BL/6 mice and human dermal papilla (HDP) cells. Topical application of Pj-EE promoted hair regrowth, increased hair length, and enhanced follicular density and activity in vivo. Pj-EE treatment also partially restor...

Intensifying stratification in marginal seas is transforming planktonic ecosystems, yet the interaction between taxonomic composition, functional traits, and biomass remains poorly quantified. Here, we analyze eukaryotic protist communities at three depth layers across three seasonal cruises (May, July, and October 2023) in the northern East China Sea (nECS). We combined small-organelle enriched metagenomics (SoEM) with high-p...

Ethyl gallate (EG), a phenolic ester derivative of gallic acid previously identified from the freshwater green alga Spirogyra sp., was investigated in this study as a bioactive constituent contributing to the anti-inflammatory potential of this underutilized algal resource. The anti-inflammatory activity of EG was systematically evaluated using both in vitro and in vivo models. In lipopolysaccharide (LPS)-stimulated RAW 264.7...

To clarify an unidentified marine sand-dwelling dinoflagellate isolated from samples collected at a sandy beach of Geoje Island, Korea, its morphology and molecular phylogeny based on the small and partial large subunit rRNA gene sequences were examined. In addition, growth responses and fatty acid content of the isolate under different temperature conditions were investigated to assess its physiological traits and aquaculture...

The green macroalgal genus Ulva is widely distributed, ecologically important, and serves as a versatile bioresource. In South Korea, where Ulva species are utilized as edible seaweeds, challenges such as low production and the impact of green tides on aquaculture and marine ecosystems are evident. Recognizing the limitations of morphologybased taxonomy, there has been a shift towards the integration of DNA-based methods for s...

Pyropia yezoensis, a red macroalga distributed in the intertidal zone, serves as an important model organism for studying the adaptive mechanisms of intertidal seaweeds in response to abiotic stressors. Additionally, it is a significant economic seaweed due to its high nutrient content and is widely cultivated in China, Japan, and Korea. Despite its importance, existing molecular tools for genetic transformation remain limited...

The taxonomy of filamentous Bangiales was challenging due to its plastic and simple morphology. Molecular approaches play a significant role in revealing cryptic biodiversity and resolving phylogenetic relationships. Nonetheless, the biodiversity of filamentous Bangiales in many regions, including China, has not been thoroughly investigated yet using updated methods. In this study, we investigated the biodiversity of filamento...

The genus Colaconema represents a significant group of filamentous red algae that commonly grow as epiphytes, endophytes, or epi-endophytes on a variety of economically important macroalgae, potentially affecting host health and aquaculture productivity. Although numerous Colaconema species have been described worldwide, few have been reported from China based on integrated morphological and molecular analyses. In this study,...

Lobophora (Dictyotales, Phaeophyceae) is an ecologically important seaweed genus in tropical and subtropical marine ecosystems. This alga exhibits cryptic diversity and morphological plasticity, which require taxonomic delineations that primarily depend on DNA analyses, complemented by morphological and ecological data. Species diversity and distribution within Southeast Asia remain understudied compared to well-documented reg...

The first records of the red algal genus Incendia are reported from five Micronesian islands. The distribution range of Incendia crenata is expanded to include the islands of Kosrae and Pohnpei in Micronesia. Additionally, eight new species are described based on morphological and molecular analyses: Incendia chamoruensis sp. nov., I. dixonii sp. nov., I. fragilis sp. nov., I. orotensis sp. nov., I. gordonii sp. nov., I. lobba...

Sargassum thunbergii is a large brown seaweed endemic to the Northwest of Pacific Ocean, widely distributed in the warm temperate coastal waters of South Korea, China, and Japan. It is abundant in resources and has a long history of application, widely used in food, medicine, and feed. In recent years, it has also been used to restore marine ecology. To date, only one review has been published on Sargassum thunbergii aquacultu...

The diatom Phaeodactylum tricornutum is known for its rapid growth and high fucoxanthin content (1–3% of dry weight), a photosynthetic pigment with considerable pharmaceutical and nutraceutical potential. Despite these advantages, the commercial biotechnological applications of this organism have not yet been realized, primarily due to challenges in scaling up photobioreactor (PBR) systems, as well as issues with the organism’...

Due to the fact that Pyropia haitanensis contains numerous nutritional and biofunctional compounds, its development prospects are very promising. However, asynchronous conchocelis development has limited the large-scale use of new varieties of P. haitanensis. In this study, we combined lipid metabolomic and transcriptomic data to analyze the free-living conchocelis of two P. haitanensis strains that vary regarding conchocelis...

Phytoplankton, the primary producers of marine ecosystems, play a crucial role in sustaining primary production. This study investigates spatiotemporal variations in phytoplankton functional groups (PFGs) and their environmental drivers across the Bohai, Yellow, and East China Seas (BYECS) from 2003 to 2022. Sea surface temperature exhibited a significant warming trend (sea surface temperature [SST]; τ > 0.48, p

Coastal saline-alkaline soils in China's Yellow River Delta represent vital yet underutilized arable reserves, where crop productivity is severely constrained by dynamic salinity-alkalinity stress, compounded by the scarcity of native stress-adapted biological resources for sustainable remediation. This study addressed this critical gap through in situ isolation of a novel halo-alkaliphilic microalga from saline waters, identi...

Ischemic stroke (IS) has emerged as one of the leading causes of mortality and disability in adults worldwide. Hypoxia-inducible factor 1α (HIF-1α) signaling pathway plays a critical role in endogenous neuroprotective mechanisms following IS. Sargassum fusiforme is a significant marine algal resource. In previous research, we isolated bioactive fucoidan from acid-processed S. fusiforme, and demonstrated its anti-inflammatory a...

Macroalgae host diverse epiphytic eukaryotes that contribute to coastal biodiversity and ecosystem function. Yet how fine-scale host traits shape these communities remains unclear. Using small organelle-enriched metagenomics (SoEM), we profiled epiphytes on eight intertidal macroalgal species from Korea and tested whether host cortical cell layer thickness predicts community structure. Epiphytic composition separated strongly...

Desmodesmus (Scenedesmaceae) is a ubiquitous genus of green algae that inhabits freshwater environments. Desmodesmus species are characterized by distinct morphological features such as spines, warts, ribs, and rosettes. These ultrastructures are crucial for morphological characterization and species identification within this genus but are frequently overlooked in light microscopy (LM), which can lead to misidentification. Th...

Nanovesicles (NVs) derived from Pyropia yezoensis, a red alga extensively cultivated in East Asian coastal regions, are emerging as a promising therapeutic tool for promoting wound healing. This study aimed to evaluate the physiological properties and wound healing efficacy of Pyropia yezoensis-derived nanovesicles (PyNVs). Using various cell culture models, we analyzed the effects of PyNVs on skin cell proliferation, migratio...