Effectively managing eutrophic estuaries under climate change requires a quantitative understanding of how microbial communities respond to multiple environmental stressors. However, predicting these responses is challenging due to complex, non-linear interactions. This study addresses this gap by developing a machine learning framework to model the seasonal dynamics of the bacterial community in the chronically eutrophic Pearl River Estuary. We aimed to identify key environmental drivers, define their ecological thresholds, and forecast community shifts under future climate scenarios. Our models revealed that temperature, silicate, and the nitrite/dissolved oxygen were the dominant drivers, collectively explaining 66-82 % of the community variance. Crucially, we identified specific environmental thresholds beyond which the abundance of key phyla, including Firmicutes, Actinobacteriota, and Proteobacteria, significantly changed. Under a high-emission scenario (SSP5-8.5), the model projects an increase in β-diversity but a potential 4.88 % decline in the relative abundance of key biomarker taxa, with the upper and lower estuary emerging as hotspots for future community restructuring. This study provides a robust, predictive tool that moves beyond monitoring to proactive management. The identified thresholds offer clear, data-driven targets for pollution control and ecosystem restoration, providing a transferable model for developing evidence-based management strategies for other complex estuarine systems globally.

Recent studies have reported the presence of 6:2 fluorotelomer ethoxylates (FTEOs) as an emerging group of perfluoroalkyl and polyfluoroalkyl substances. However, the environmental relevance of additional FTEO homologues and analogues remains rarely investigated. Through a combination of suspect screening and homologue-based nontargeted analysis, we identified a total of 60 FTEO homologues and 30 perfluoroalkyl ether ethoxylate (PFAEE) homologues in commercial antifog products. They included homologue groups of 4:2 FTEOs (n = 16), 6:2 FTEOs (n = 17), 8:2 FTEOs (n = 12), 10:2 FTEOs (n = 8), 12:2 FTEOs (n = 7), perfluorobutyl ether ethoxylates (n = 15), and perfluorohexyl ether ethoxylates (n = 15). Among them, 4:2 FTEOs, 6:2 FTEOs, and perfluorobutyl ether ethoxylates were also frequently detected in house dust (n = 120) collected from South China, with semiquantified concentrations measured to be 30.4, 36.0, and 55.3 ng/g. Among each homologue group, the composition profiles of individual homologues with different numbers of repeated ethoxy units resembled between antifog products and house dust. A toxicological priority index (ToxPi) approach revealed the highest risk of 6:2 FTEOs among all of the identified FTEOs and PFAEEs, although the risks from other groups should not be overlooked. Collectively, our work reveals the complexity of diverse FTEO homologues and reports the presence of PFAEEs for the first time in indoor environments, raising the need for further investigating their sources, environmental distribution, and potential human exposure.

Ultrashort-chain per- and polyfluoroalkyl substances (USC-PFAS) have gained increasing attention due to their ubiquitous environmental presence and escalating environmental concerns. However, data on their presence in corals remain lacking. This study investigated the concentrations of USC-PFAS, including trifluoroacetic acid (TFA), perfluoropropionic acid (PFPrA), trifluoromethanesulfonate (TFMS), perfluoroethanesulfonate (PFEtS), perfluoropropanesulfonate (PFPrS), and bisperfluoromethane sulfonimide (bis-FMeSI), along with other legacy and emerging PFAS in reef-building coral samples (n = 54) from the Beibu Gulf of the South China Sea. Among the USC-PFAS, TFA, PFPrA, and bis-FMeSI exhibited detection rates of 100%, 74%, and 72%, respectively, in coral samples. TFA dominated the PFAS profile, accounting for 86% of the total concentrations by weight, with concentrations (median: 23 ng/g dw) far exceeding those of all other legacy and emerging PFAS. The wet-weight-based logarithm bioaccumulation factors (log(10) BAFs) from seawater to coral were estimated to be 1.85-3.60 for TFA, 2.07-4.09 for PFPrA, and 0.56-3.43 for bis-FMeSI, suggesting their bioaccumulative potential in reef-building corals. This study provides the first evidence of the widespread occurrence of USC-PFAS, particularly TFA, in reef-building corals, underscoring the need for further research into their potential ecological risks.

Climate-driven extremes in precipitation are fundamentally altering the hydrological regimes of wetland ecosystems. However, the mechanistic understanding of how soil microbial communities and their metabolic functions respond to precipitation change, and how these responses regulate soil organic carbon (SOC) dynamic, remains limited. Here, we leveraged a 7-year precipitation manipulation experiment (±40%) in a coastal wetland and applied genome-resolved metagenomics to systematically examine microbial community structure, ecological networks, and key biogeochemical functions (carbon fixation and degradation). We found that although microbial community structure showed no pronounced response to increased precipitation, decreased precipitation reorganized the community, as evidenced by higher β-diversity and more complex co-occurrence networks with strengthened positive interactions. Compared with dominant species, rare species played a more important role in maintaining the stability of microbial networks. Functional potential for carbon degradation and fixation remained relatively stable under decreased precipitation. In contrast, increased precipitation concurrently suppressed degradation of polysaccharides and aromatic compounds, and some carbon fixation pathways, such as Acetyl-CoA (rAcCoA) pathway. Collectively, decreased and increased precipitation induced asymmetric responses in microbial communities, with decreased precipitation primarily reshaping community composition but having little effect on functional potential, whereas increased precipitation predominantly altered functional profiles without substantially changing community structure. We further found microbial community reassembly decoupled SOC content. Together, this study highlights that prolonged precipitation extremes shape coastal wetland microbiomes through divergent ecological trajectories; however, these microbial shifts may not necessarily translate directly into changes in soil carbon storage.

Mango bacterial black spot is a major disease limiting mango production, which is now causing increasingly severe economic losses. In this study, we analyzed the differences in the composition and structure of bacterial and fungal communities in the pulp and leaves between the healthy mangoes of variety Kate and those affected by bacterial black spot, and attempted to explore potential biocontrol microorganisms for mangoes. The results showed there existed significant differences in microbial communities, the bacterial Stenotrophomonas, Curtobacterium, Massilia and fungous Penicillium, Alternaria, Aureobasidiu showed great abundance both in pulps and leaves. Some potential pathogenic bacteria, such as Pseudomonas, Xanthomonas, and Burkholderia, were also significantly enriched in the infected groups. In both the infected and healthy groups, the overall community structure of endophytic bacteria and fungi within the same organs was more similar, indicating that the composition of endophytes is organ-specific. After infection, the abundance of the potential probiotic bacterium class Paenibacillus was significantly increased both in leaves and pulp, suggesting that the pathogen invasion stimulated the defense systems of endophytes. Presumably, these Paenibacillus might be developed as defense bacteria for black spot as well as other plant diseases.

The ubiquitous occurrence of organic UV stabilizers (OUVs) poses a potential threat to marine fish, but the metabolism of OUVs in the body remains a missing piece of the puzzle in their ecotoxicology. This study investigated the in vitro metabolism of six OUVs in the liver microsomes of an economically valuable marine fish (Lateolabrax japonicus). The depletion of the six OUVs follows first-order kinetics in the microsomes, with in vitro depletion rate constants (kdepl) ranging from 0.23 to 0.40/h. The intrinsic clearance (CLint) of 1H-benzotriazole (BT) was estimated to be 0.0026 μL/(min·mg·protein). The enzyme inhibition experiments and molecular docking results highlight the importance of cytochrome P450 enzyme (CYP) 3A4 in OUVs metabolism. Among the 4 metabolizable compounds, some metabolites from hydroxylation, methylation, acetylation and conjugation were tentatively identified. In addition, the in vitro transformation rates can more accurately predict the whole-body bioconcentration potential via an in vitro to in vivo extrapolation (IVIVE) model.

Lipophilic marine phycotoxins (LMTs), primarily produced by toxigenic dinoflagellates, pose significant risks to marine ecosystems and human health due to their toxicity and widespread distribution. This study investigates the spatial and temporal distribution of LMTs in the surface seawater from representative estuarine and bay areas of the South China Sea (SCS) during period from 2022‒2023. Using active solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry (Active-SPE-LC-MS/MS), the study revealed that significantly higher LMTs concentrations in semi-enclosed bays (13.15 ± 8.61 ng L-1) compared to estuarine regions (8.55 ± 8.59 ng L-1), with Daya Bay (DB) and Jian River Estuary (JRE) exhibiting the highest toxin levels. The most prevalent toxins were diarrhetic shellfish toxins (OA, DTX1) and pectenotoxin-2 (PTX2), with PTX2 being dominant in most regions. Seasonal variations were evident, with higher LMTs concentrations observed during the wet season, particularly in spring and summer. Principal component analysis (PCA) revealed distinct toxin profiles, with PTX2, GYM, and OA being prevalent in the Pearl River Estuary (PRE), while AZA2 and DTX1 were more abundant in Qinzhou Bay (QB). The study highlights the influence of local environmental conditions, such as seasonal and region variations on LMTs distribution. These findings provide critical insights into the ecological dynamics of LMTs in eutrophic coastal waters, emphasizing the need for continuous monitoring to mitigate risks to marine ecosystems and human health. This research contributes to a deeper understanding of LMTs distribution patterns in the SCS, supporting future risk assessments and management strategies.

Estuaries are critical for land-ocean carbon exchange, but coupling mechanisms between air-sea CO2 fluxes (FCO2) and phytoplankton gross primary productivity (GPP) remain poorly understood. This study used high-frequency underway monitoring in the Lingdingyang Estuary to resolve spatiotemporal interplays between FCO2 and GPP. Annual mean FCO2 was 20.29 +/- 23.34 mol C m(-2) yr(-1), with flooding season (82.97 +/- 80.49 mmol C m(-2) d(-1)) an order of magnitude higher than dry season. Gross primary productivity averaged 2.23 +/- 2.07 mol C m(-2) yr(-1), increasing significantly during flooding. The results revealed a distinct "source-to-sink" FCO2 gradient, with a 116% reduction over similar to 40 km, primarily driven by phytoplankton activity. Biological processes explained 30-50% of FCO2 variability. While net autotrophy in the mid-estuary reduced FCO2 by 48.6 mmol C m(-2) d(-1) during flooding, heterotrophic activity downstream offset 40-60% of GPP-driven uptakes. This study quantifies how urban estuary oscillate between carbon source and sink states, providing parameters for blue carbon frameworks and demonstrating that eutrophication-driven loads reduce overall carbon sequestration efficiency through enhanced heterotrophic activities.

High temperatures inhibit Phaeocystis globosa colony formation by reducing synthesis and enhancing degradation of colony mucus components, but this insufficiently explains the occurrence of colonial blooms in tropical summers. P. globosa enhances colony development as a defensive response to zooplankton grazing risks, playing key roles in their success in marine systems. To evaluate whether predation risks modulate thermal responses, P. globosa grown alone and exposed to grazing cues associated with ciliates and copepods were maintained at temperatures ranging from 13 to 30°C. P. globosa exposed to both grazing risks exhibited defensive responses, including higher colony abundances, greater colony diameters and higher colonial cell abundances. Solitary cells of P. globosa exposed to grazing cues grew at 30°C, whereas non-exposed cells failed to survive at this temperature. Grazer-induced P. globosa developed colonies at 15–30°C, whereas colonies without induction were restricted to 17–25°C. Thermal performance curve modeling revealed that exposure to grazing cues significantly increased the critical thermal maximum by nearly 5°C. Fear of predation increased the tolerance of P. globosa to high temperatures, enabling colonial blooms to grow at lower latitudes and potential reducing vulnerability of P. globosa blooms to climate warming. These findings emphasize the importance of considering fear effects to accurately understand impacts of climate change on phytoplankton dynamics.

As an emerging group of per- and polyfluoroalkyl substances (PFAS), fluorotelomer ethoxylates (FTEOs) are widely employed as a major ingredient in antifog products. However, knowledge about their environmental distribution and human exposure remains scarce. Herein, we reported the ubiquitous detection of 6:2 FTEO homologues in popular antifog products (n = 47), indoor dust from residential homes (n = 80), and serum of pregnant women (n = 90) living in South China, demonstrating broad use and widespread human exposure. The cumulative concentrations of 6:2 FTEOs ranged from below the limit of detection (

Microplastics have become ubiquitous in the global marine environment, posing substantial influences on marine organism health, food web function and marine ecosystem structure. Protozoan grazers are known for their ability to improve the biochemical constituents of poor-quality algae for subsequent use by higher trophic levels. However, the effects of microplastics on the trophic upgrading of protozoan grazers remain unknown. To address this knowledge gap, the ciliate Euplotes vannus and the heterotrophic dinoflagellate Oxyrrhis marina were exposed to microplastic particles (5 mu m) for four days with various concentrations (1-20 mg/L). Both O. marina and E. vannus ingested microplastics. At the exposure level of 20 mg/L, the ingestion rate, growth rate, biovolume, and carbon biomass of E. vannus were significantly decreased by 28.18 %, 32.01 %, 30.46 %, and 82.27 %, respectively, while such effects were not observed for O. marina. The contents of highly unsaturated fatty acids in O. marina and E. vannus on a mixed diet of microplastic particles and green algae significantly reduced by 8.66 % and 41.49 % relative to feeding only on green algae, respectively. Besides, we also observed an increase in the composition of C18:3 (omega-3) and C20:3 (omega-3) concurrence with a significant decrease in C16:0 and C18:0 in E. vannus after 96 h exposure at 20 mg/L. These results indicate that microplastics can weaken trophic upgrading of the nutritional quality by protozoan grazers, which may consequently alter the function of food webs.

Understanding the near-ground vertical and temporal photochemical O3 formation mechanism is important to mitigate O3 pollution. Here, we measured the vertical profiles of O3 and its precursors at six different heights, ranging from 5 to 335 m, using a newly built vertical observation system in the Pearl River Delta (PRD) region of China. The net photochemical ozone production rate (P(O3)net) and O3 formation sensitivities at various heights were diagnosed using an observation-based model coupled with the Master Chemical Mechanism (MCM v3.3.1). Moreover, to assess model performance and identify the causative factors behind O3 pollution episodes, the P(O3)net was measured at 5 m above ground level with a custom-built detection system. In total, three O3 pollution episodes and two non-episodes were captured. The identified O3 pollution episodes were found to be jointly influenced by both photochemical production and physical transport, with local photochemical reactions playing a major role. The high index of agreement (IOA) calculated by comparing the modelled and measured P(O3)net values indicated the rationality of investigating the vertical and temporal variability in O3 formation mechanisms using model results. However, the measured P(O3)net values were generally higher than the modelled P(O3)net values, particularly under high-NOx conditions, which may indicate a potential underestimation of total RO2 by the model. Throughout the measurement period, the contribution of different reaction pathways to O3 production remained consistent across various heights, with HO2 + NO as the major O3 production pathway, followed by RO2 + NO. We observed that P(O3)net decreased with an increase in measurement height, which was primarily attributed to the reduction in O3 precursors, such as oxygenated volatile organic compounds (OVOCs) and non-methane hydrocarbons (NMHCs). The O3 formation regimes were similar at different heights during both episodes and non-episodes, either being located in the VOC-sensitive regime or in the transition regime that is more sensitive to VOCs. Diurnally, photochemical O3 formation typically remained in the VOC-sensitive regime during the morning and noon, but it transitioned to the transition regime and was more sensitive to VOCs in the afternoon at around 16:00 LT (local time). Vertical and temporal photochemical O3 formation is most sensitive to OVOCs, suggesting that targeting specific VOCs for control measures is more practical and feasible at the observation site. The vertical temporal analysis of O3 formation mechanisms near the ground surface in this study provides critical foundational knowledge that can be used to formulate effective short-term emergency and long-term control strategies to combat O3 pollution in the PRD region of China.

The effects of different dissolved organic phosphorus (DOP) associated with distinct iron conditions (iron deficient (dFe), ferric ions (Fe3+), and colloidal iron (CFe)) on algal growth and arsenate (As(V)) metabolism were systematically evaluated and compared in Microcystis aeruginosa. . Two chemical forms of DOP (D-glucose-6- phosphate (GP) and phytic acid (PA)), as well as dissolved inorganic phosphorus (DIP), were employed as distinct phosphorus environments. The results revealed that As(V) metabolism of M . aeruginosa was more influenced by different phosphorus forms than by different iron conditions. Conversely, the release of microcystins in the media was found to be significantly more affected by the different phosphorus forms than by the iron conditions. Moreover, DOP was observed to promote arsenic (As) biotransformation, particularly the efflux of methylated As from a single algal cell, whereas DIP was found to primarily facilitate As(V) accumulation in algae. The total As metabolism amount per algal cell under PA was observed to be five times that observed under DIP and GP. The influence of iron conditions on the synthesis of algal metabolites was notable, as evidenced by the metabolites identified in algae of aliphatic (delta 1.28-1.68), humic acid-like and aromatic protein-like substances through H-1-NMR spectra and three-dimensional excitation-emission matrix fluorescence spectroscopy analysis. This impact was particularly notable at Fe3+ conditions, due to the role of Fe3+ as a micronutrient with highly bioavailable forms, which enhanced the synthesis of organic compounds in algae and promoted algal growth. Consequently, Fe3+ could inhibit As accumulation under DIP but promote it under DOP. The obtained results facilitate a more comprehensive understanding of the combined role of different phosphorus forms and iron conditions in algal bloom outbreaks and As(V) metabolism.

The cold-seep sponge holobionts are attracting growing attention in recent years. In this study, we utilized 16S rRNA amplicons to characterize the bacterial communities of six deep-sea sponge species found in sponge grounds at the Formosa Ridge cold seep in the South China Sea. Bacterial communities in these geographically proximal sponge species are dominated by Proteobacteria (mainly Gammaproteobacteria and Alphaproteobacteria) but exhibit distinct diversity and compositions among communities. Further analysis revealed that the SUP05 clade (Thioglobaceae) dominated most of the sponge samples. Meanwhile, phylogenetic analysis showed that the six sponge species harbored diverse SUP05 OTU phylotypes, indicating significant divergence within this clade. Additionally, operational taxonomic units (OTUs) of the family Methylomonadaceae, another abundant group in these sponges, displayed a significant genetic distance both from each other and from known species. Our findings support the hypothesis of the host-species specificity of sponge-associated bacterial communities, a widely accepted concept in shallow-water and other deep-sea sponges. The presence of dominant functional microbes, such as sulfur- and methanol-oxidizing bacteria, suggests their crucial role as chemosynthetic symbionts in facilitating the niche adaption of sponge hosts to the cold seep ecosystem. In conclusion, our study reveals the diverse and novel bacterial communities in deep-sea sponges from cold seep environments, contributing new knowledge to the host-species specificity of bacterial communities within sponges and highlighting the potential significance of functional microbes in cold seep ecosystems with dynamic energy supplies.

Current process-based research mainly uses box models to evaluate photochemical ozone production and destruction rates, and it is unclear to what extent the photochemical reaction mechanisms are elucidated. Here, we modified and improved a net photochemical ozone production rate (NPOPR, P(O3)net) detection system based on the current dual-channel reaction chamber technique, which makes the instrument applicable to different ambient environments, and its various operating indicators were characterized, i.e., “airtightness”, light transmittance, wall losses of the reaction and reference chambers, conversion rate of O3 to NO2, air residence time, and performance of the reaction and reference chambers. The limits of detection of the NPOPR detection system were determined to be 0.07, 1.4, and 2.3 ppbv h−1 at sampling flow rates of 1.3, 3, and 5 L min−1, respectively. We further applied the NPOPR detection system to field observations at an urban site in the Pearl River Delta (China). During the observation period, the maximum value of P(O3)net was 34.1 ppbv h−1, which was ∼ 0 ppbv h−1 at night within the system detection error and peaked at approximately noon local time. The daytime (from 06:00–18:00 LT) average value of P(O3)net was 12.8 (± 5.5) ppbv h−1. We investigated the detailed photochemical O3 formation mechanism in the reaction and reference chambers of the NPOPR detection system using a zero-dimensional box model. We found that the photochemical reactions in the reaction chamber were very close to those in ambient air, but there was not zero chemistry in the reference chamber because the reaction related to the production and destruction of RO2 (= HO2 + RO2) continued in the reference chamber, which led to a small amount of P(O3)net. Therefore, the P(O3)net measured here can be regarded as the lower limit of the real P(O3)net in the atmosphere; however, the measured P(O3)net was still ∼ 7.5 to 9.3 ppbv h−1 higher than the modeled P(O3)net value depending on different modeling methods, which may be due to the inaccurate estimation of HO2 / RO2 radicals in the modeling study. Short-lived intermediate measurements coupled with direct P(O3)net measurements are needed in the future to better understand O3 photochemistry. Our results show that the NPOPR detection system can achieve high temporal resolution and continuous field observations, which helps us to better understand photochemical O3 formation and provides a key scientific basis for continuous improvement of air quality in China.

Cadmium (Cd) and sodium (Na) are two of the most phytotoxic metallic elements causing environmental and agricultural problems. Metallothioneins (MTs) play an important role in the adaptation to abiotic stress. We previously isolated a novel type 2 MT gene from Halostachys caspica (H. caspica), named HcMT, which responded to metal and salt stress. To understand the regulatory mechanisms controlling HcMT expression, we cloned the HcMT promoter and characterized its tissue-specific and spatiotemporal expression patterns. β-Glucuronidase (GUS) activity analysis showed that the HcMT promoter was responsive to CdCl2, CuSO4, ZnSO4 and NaCl stress. Therefore, we further investigated the function of HcMT under abiotic stress in yeast and Arabidopsis thaliana (Arabidopsis). In CdCl2, CuSO4 or ZnSO4 stress, HcMT significantly enhanced the metal ions tolerance and accumulation in yeast through function as a metal chelator. Moreover, the HcMT protein also protected yeast cells from NaCl, PEG and hydrogen peroxide (H2O2) toxicity with less effectiveness. However, transgenic Arabidopsis carrying HcMT gene only displayed tolerance to CdCl2 and NaCl, accompanying by higher content of Cd2+ or Na+ and lower H2O2, compared to wild-type (WT) plants. Next, we demonstrated that the recombinant HcMT protein has the ability to bind Cd2+ and the potential of scavenging ROS (reactive oxygen species) in vitro. This result further confirmed that the role of HcMT to influence plants to CdCl2 and NaCl stress may bind metal ions and scavenge ROS. Overall, we described the biological functions of HcMT and developed a metal- and salt-inducible promoter system for using in genetic engineering.

BACKGROUNDMarine bacteria secrete a variety of proteases, which are a good source to explore proteases with application value. However, only a few marine bacterial proteases with a potential in bioactive peptides preparation have been reported. RESULTSThe metalloprotease A69 from the marine bacterium Anoxybacillus caldiproteolyticus 1A02591 was successfully expressed in the food safe bacterium Bacillus subtilis as a secreted enzyme. A technique to efficiently produce protease A69 in a 15-L bioreactor was established, with a production of 8988 U mL(-1). Based on optimizing the hydrolysis parameters of A69 on soybean protein, a process for soybean protein peptides (SPs) preparation was set up, in which soybean protein was hydrolyzed by A69 at 4000 U g(-1) and 60 & DEG;C for 3 h. The prepared SPs had a high content (> 90%) of peptides with a molecular mass less than 3000 Da and contained 18 amino acids. The prepared SPs showed high angiotensin-converting enzyme (ACE)-inhibitory activity, with an IC50 value of 0.135 mg mL(-1). Moreover, three ACE-inhibitory peptides, RPSYT, VLIVP and LAIPVNKP, were identified from the SPs using liquid chromatography-mass spectrometry analysis. CONCLUSIONThe marine bacterial metalloprotease A69 has a promising potential for preparing SPs with good nutritional and potential antihypertensive effects, laying a good foundation for its industrial production and application. & COPY; 2023 Society of Chemical Industry.

Phaeocystis globosa blooms frequently occur in the Southeast China Sea and cause significant negative impacts on coastal ecology and mariculture. The P. globosa blooms in southeastern China are very different compared to those of European strains, suggesting that differences may exist in their morphological, phylogenetic, and life history traits. In this study, seven strains of P. globosa isolated from Southeast China Sea that were typical strains of algal blooms in the region, in addition to one strain from the Gulf of Mexico (CCMP629), were comprehensively evaluated to better understand region-specific differences of the species. Significant differences were not observed in the internal cell structures and other characteristics compared to those of European strains, while differences in cell surface structures were apparent. For example, small and large flagellated Chinese P. globosa cells exhibited two flagella with slightly unequal lengths and a short haptonema, the surfaces of small flagellated cells were not covered by scales, and colony cell diameters were smaller. 18S rRNA sequence phylogenetic analysis also revealed that P. globosa comprised a species complex with two ecotypes (warm- and cold-water types), of which the strains from the southeastern coast of China and CCMP629 belonged to the warm-water type. In addition, the life cycles and variable modes of P. globosa colony formation were evaluated in detail. The algal bloom may be due to the rapid colonies formation by budding and colony fragments. These results provide new insights into the life cycle of P. globosa and highlight the differences in morphological and phylogenetic relationships between strains from the southeast coast of China and those from coastal European regions.

In 2 S 3 , as a promising environmentally benign semiconductor, is used as a buffer layer in thin‐film solar cells due to its high electron mobility, low toxicity, and excellent thermal and chemical stability. The preparation of a high‐quality In 2 S 3 film is crucial for the improvement of its carrier extraction ability and subsequent deposition of absorber layers. Herein, it is demonstrated for the first time that a posttreatment of In 2 S 3 film with ZnCl 2 solution is able to serve as buffer layer for constructing superstrate Sb 2 Se 3 solar cells. The posttreatment with ZnCl 2 not only prevents In 2 S 3 from excessive oxidation during annealing process, but also facilitates the growth of (hk1) orientation of Sb 2 Se 3 , thereby improving the interfacial contact of In 2 S 3 /Sb 2 Se 3 . The improved heterojunction quality suppresses the carrier recombination at the interface, and enhances the charge extraction ability of In 2 S 3 . As a result, the power conversion efficiency of Sb 2 Se 3 solar cell increases from 2.63% to 5.00%. Herein, a facile and effective strategy is provided for the application of In 2 S 3 as the buffer layer in inorganic chalcogenide solar cells.

Phaeocystis globosa blooms have frequently occurred in the coastal waters of South China, although information about the structure and composition of their colonies is scarce. Colony cell abundances, as well as concentrations of mucous particular organic carbon (POC), cellular chlorophyll a, and nutrients in intra-colony fluids were investigated during a P. globosa bloom that occurred in late January 2021 in Mirs Bay, China. Giant colonies exhibited unique characteristics that considerably differed from previous observations of P. globosa. Colonies ranged from 0.47 to 1.83 cm in diameter, with up to 4.0 x 106 cells distributed within mucilaginous matrices. Colony cell densities and mucous carbon densities linearly increased with colony diameters, suggesting that colony envelopes become thicker and more structurally stable as colonies grow bigger. The contributions of mucous carbon relative to total carbon ranged from 47% to 84% and were positively associated with colony size. In contrast, chlorophyll a concentrations per colonial cell decreased as colony size increased. Intra-colony fluids contained greater nitrate, phosphate, and silicate concentrations, but less ammonium and nitrite concentrations relative to ambient seawater, suggesting constrained nutrient flux across the mucous layer. The occurrence of blooms caused by giant P. globosa colonies may influence food web structures and carbon cycling in sub-tropical Chinese waters.