Functional vertical connectivity of microbial communities in the ocean.

Sinking particles are a critical conduit for the transport of surface microbes to the ocean's interior. Vertical connectivity of phylogenetic composition has been shown; however, the functional vertical connectivity of microbial communities has not yet been explored in detail. We investigated protein and taxa profiles of both free-living and particle-attached microbial communities from the surface to 3000 m depth using a combined metaproteomic and 16S rRNA amplicon sequencing approach. A clear compositional and functional vertical connectivity of microbial communities was observed throughout the water column with Oceanospirillales, Alteromonadales, and Rhodobacterales as key taxa. The surface-derived particle-associated microbes increased the expression of proteins involved in basic metabolism, organic matter processing, and environmental stress response in deep waters. This study highlights the functional vertical connectivity between surface and deep-sea microbial communities via sinking particles and reveals that a considerable proportion of the deep-sea microbes might originate from surface waters and have a major impact on the biogeochemical cycles in the deep sea.

Molecular Mechanisms of the Generation and Accumulation of Gas at the Interface.

Gas-evolving reactions are widespread in chemical and energy fields. However, the generated gas will accumulate at the interface, which reduces the rate of gas generation. Understanding the microscopic processes of the generation and accumulation of gas at the interface is crucial for improving the efficiency of gas generation. Here, we develop an algorithm to reproduce the process of catalytic gas generation at the molecular scale based on the all-atom molecular dynamics simulations and obtain the quantitative evolution of the gas generation, which agrees well with the experimental results. In addition, we demonstrate that under an external electric field, the generated gas molecules do not accumulate at the electrode surface, which implies that the electric field can significantly increase the rate of the gas generation. The results suggest that the external electric field changes the structure of the water molecules near the electrode surface, making it difficult for gas molecules to accumulate on the electrode surface. Furthermore, it is found that gas desorption from the electrode surface is an entropy-driven process, and its accumulation at the electrode surface depends mainly on the competition between the entropy and the enthalpy of the water molecules under the influence of the electric field. These results provide deep insight into gas generation and inhibition of gas accumulation.

Improving the genome and proteome annotations of the marine model diatom Thalassiosira pseudonana using a proteogenomics strategy.

Diatoms are unicellular eukaryotic phytoplankton that account for approximately 20% of global carbon fixation and 40% of marine primary productivity; thus, they are essential for global carbon biogeochemical cycling and climate. The availability of ten diatom genome sequences has facilitated evolutionary, biological and ecological research over the past decade; however, a complimentary map of the diatom proteome with direct measurements of proteins and peptides is still lacking. Here, we present a proteome map of the model marine diatom Thalassiosira pseudonana using high-resolution mass spectrometry combined with a proteogenomic strategy. In-depth proteomic profiling of three different growth phases and three nutrient-deficient samples identified 9526 proteins, accounting for ~ 81% of the predicted protein-coding genes. Proteogenomic analysis identified 1235 novel genes, 975 revised genes, 104 splice variants and 234 single amino acid variants. Furthermore, our quantitative proteomic analysis experimentally demonstrated that a considerable number of novel genes were differentially translated under different nutrient conditions. These findings substantially improve the genome annotation of T. pseudonana and provide insights into new biological functions of diatoms. This relatively comprehensive diatom proteome catalog will complement available diatom genome and transcriptome data to advance biological and ecological research of marine diatoms. Supplementary Information: The online version contains supplementary material available at 10.1007/s42995-022-00161-y.

Self-propelled continuous transport of nanoparticles on a wedge-shaped groove track.

Controlling the directional motion of nanoparticles on the surface is particularly important for human life, but achieving continuous transport is a time-consuming and demanding task. Here, a spontaneous movement of nanoflakes on a wedge-shaped groove track is demonstrated by using all-atom molecular dynamics (MD) simulations. Moreover, an optimized track, where one end of the substrate is cut into an angle, is introduced to induce a sustained directional movement. It is shown that the wedge-shaped interface results in a driving force for the nanoflakes to move from the diverging to the converging end, and the angular substrate provides an auxiliary driving force at the junction to maintain continuous transport. A force analysis is carried out in detail to reveal the driving mechanism. Moreover, the sustained transport is sensitive to the surface energy and structural characteristics of the track: the nanoflakes are more likely to move continuously on the track with lower surface energy and a smaller substrate and groove opening angle. The present findings are useful for designing nanodevices to control the movement of nanoparticles.

Wetting-State-Induced Turning of Water Droplet Moving Direction on the Surface.

The spontaneous directional movement of water droplets on a wedge-shaped groove has gained extensive attention due to the advantage of not requiring energy input and its potential wide applications. However, manipulating the direction of movement of water droplets on a wedge-shaped groove has been not fully achieved, and the fundamental understanding of its underlying mechanism remains unclear. Here, molecular dynamics simulations and theoretical analyses are combined to reveal the mechanism of movement in opposite directions of a water droplet at the same position on the wedge-shaped groove interface. It is shown that the moving direction of the water droplet is related to its wetting state on the surface, i.e., the Wenzel and the Cassie states. A water droplet initially in the Wenzel and Cassie states will move toward the diverging and the converging ends, respectively. This phenomenon is attributed to the opposite roles played by the groove substrate and the upper layers in the two wetting states. Moreover, it is found that the water droplet is likely to move faster on a surface with a higher groove, larger opening angle and stronger hydrophobicity. These findings are expected to be of benefit for fully understanding droplet movement and shedding light on the regulation of the direction of movement of the droplets on the groove surface.

Reconstruction and analysis of potential biomarkers for hypertrophic cardiomyopathy based on a competing endogenous RNA network.

Hypertrophic cardiomyopathy (HCM) is a common heritable cardiomyopath. Although considerable effort has been made to understand the pathogenesis of HCM, the mechanism of how long noncoding RNA (lncRNA)-associated competing endogenous RNA (ceRNA) network result in HCM remains unknown. In this study, we acquired a total of 520 different expression profiles of lncRNAs (DElncRNAs) and 371 messenger RNAs (mRNA, DEGs) by microarray and 33 microRNAs (DEmiRNAs) by sequencing in plasma of patients with HCM and healthy controls. Then lncRNA-miRNA pairs were predicted using miRcode and starBase and crossed with DEmiRNAs. MiRNA-mRNA pairs were retrieved from miRanda and TargetScan and crossed with DEGs. Combined with these pairs, the ceRNA network with eight lncRNAs, three miRNAs, and 22 mRNAs was constructed. lncRNA RP11-66N24.4 and LINC00310 were among the top 10% nodes. The hub nodes were analyzed to reconstruct a subnetwork. Furthermore, quantitative real-time polymerase chain reaction results showed that LINC00310 was significantly decreased in patients with HCM. For LINC00310, GO analysis revealed that biological processes were enriched in cardiovascular system development, sprouting angiogenesis, circulatory system development, and pathway analysis in the cGMP-PKG signaling pathway. These results indicate that the novel lncRNA-related ceRNA network in HCM and LINC00310 may play a role in the mechanism of HCM pathogenesis, which could provide insight into the pathogenesis of HCM.

Diel Fluctuation Superimposed on Steady High pCO2 Generates the Most Serious Cadmium Toxicity to Marine Copepods.

Coastal systems experience diel fluctuation of pCO2 and cadmium (Cd) pollution; nevertheless, the effect of fluctuating pCO2 on Cd biotoxicity is poorly known. In this study, we initially performed the isotopically enriched organism bioassay to label Tigriopus japonicus with 113Cd (5 µg/L) to determine the Cd accumulation rate constant (kaccu) under ambient (400 µatm) and steadily (1000 µatm) and fluctuatingly elevated (1000 ± 600 µatm) pCO2 conditions for 48 h. Next, T. japonicus was interactively subjected to the above pCO2 exposures at Cd (control, 5, and 500 µg/L) treatments for 7 d. Biochemical and physiological responses for copepods were analyzed. The results showed that steadily increased pCO2 facilitated Cd bioaccumulation compared to ambient pCO2, and it was more under fluctuating acidification conditions. Despite compensatory reactions (e.g., increased energy production), Cd ultimately induced oxidative damage and apoptosis. Meanwhile, combined treatment exhibited higher toxicity (e.g., increased apoptosis) relative to Cd exposure, and even more if fluctuating acidification was considered. Intriguingly, fluctuating acidification inhibited Cd exclusion in Cd-treated copepods compared to steady acidification, linking to higher Cd kaccu and bioaccumulation. Collectively, CO2-driven acidification could aggravate Cd toxicity, providing a mechanistic understanding of the interaction between seawater acidification and Cd pollution in marine copepods.

MicroRNA expression profiles in familial hypertrophic cardiomyopathy with myosin-binding protein C3 (MYBPC3) gene mutations.

Familial hypertrophic cardiomyopathy (FHCM) is an autosomal dominant inherited disease caused by mutations in genes encoding cardiac sarcomere proteins. MicroRNAs (miRNAs) play an important role in the pathogenesis of FHCM. In the present study, we aimed to determine the miRNA profile in FHCM patients with myosin-binding protein C3 (MYBPC3) gene mutations. We recruited three FHCM patients and age- and sex-matched controls. The three probands all had hypertrophic obstructive cardiomyopathy with severe myocardial hypertrophy, and two of the three had a history of sudden cardiac death, representing a "malignant" phenotype. We then compared the miRNA expression profiles of three FHCM patients carrying MYBPC3 gene mutations with those of the normal control group using miRNA sequencing technology. Differentially expressed miRNAs were verified using real-time polymerase chain reaction (qPCR). Target genes and signaling pathways of the identified differentially expressed miRNAs were predicted using bioinformatics analysis. A total of 33 significantly differentially expressed miRNAs were detected in the peripheral blood of the three probands, of which 28 were upregulated, including miR-208b-3p, and 5 were downregulated. Real-time PCR confirmed the upregulated expression of miR-208b-3p in FHCM patients (P < 0.05). Bioinformatics analysis showed that miR-208b-3p was mainly enriched in 79 target genes including UBE2V2, MED13, YBX1, CNKSR2, GATA4, andSOX5/6, et al. Gene ontology (GO) analysis of target genes showed that miR-208b was mainly involved in the processes of negative regulation of transcription from RNA polymerase II promoter, and regulation of transcription, DNA templated. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that the target genes regulated by miR-208b-3p were mainly involved in the Wnt signaling pathway. These findings suggest that FHCM patients with MYBPC3 gene mutations have a specific miRNA expression profile, and that miR-208b-3p is significantly upregulated in cardiac hypertrophy. Our results also indicate that miRNA-208b-3p activates the Wnt signaling pathway through its target gene to promote cardiac hypertrophy.

Metaexoproteomics Reveals Microbial Behavior in the Ocean's Interior.

The proteins present in the extracellular environment of cells, named the "exoproteome," are critical for microbial survival, growth, and interaction with their surroundings. However, little is known about microbial exoproteomes in natural marine environments. Here, we used a metaproteomic approach to characterize the exoprotein profiles (10 kDa-0.2 µm) throughout a water column in the South China Sea. Viruses, together with Alpha- and Gammaproteobacteria were the predominant contributors. However, the exoprotein-producing microbial communities varied with depth: SAR11 in the shallow waters, Pseudomonadales and Nitrososphaeria in the mesopelagic layer, and Alteromonadales, Rhizobiales, and Betaproteobacteria in the bathypelagic layer. Besides viral and unknown proteins, diverse transporters contributed substantially to the exoproteomes and varied vertically in their microbial origins, but presented similar patterns in their predicted substrate identities throughout the water column. Other microbial metabolic processes subject to vertical zonation included proteolysis, the oxidation of ammonia, nitrite and carbon monoxide, C1 metabolism, and the degradation of sulfur-containing dissolved organic matter (DOM). Our metaexoproteomic study provides insights into the depth-variable trends in the in situ ecological traits of the marine microbial community hidden in the non-cellular world, including nutrient cycling, niche partitioning and DOM remineralization.

Metabolic Adaptation of a Globally Important Diatom following 700 Generations of Selection under a Warmer Temperature.

Diatoms, accounting for 40% of the marine primary production and 20% of global carbon dioxide fixation, are threatened by the ongoing ocean warming (OW). However, whether and how these ecologically important phytoplankton adapt to OW remains poorly unknown. Here, we experimentally examined the metabolic adaptation of a globally important diatom species Skeletonema dohrnii (S. dohrnii) to OW at two elevated temperatures (24 and 28 °C compared with 20 °C) under short-term (∼300 generations) and long-term (∼700 generations) selection. Both warming levels significantly increased the cell growth rate but decreased the chlorophyll a content. The contents of particulate organic carbon (POC) and particulate organic nitrogen (PON) decreased significantly initially (i.e., until 300 generations) at two temperature treatments but completely recovered after 700 generations of selection, suggesting that S. dohrnii ultimately developed thermal adaptation. Proteomic analysis demonstrated that elevated temperatures upregulated energy metabolism via glycolysis, tricarboxylic acid cycle, and fatty acid oxidation as well as nitrogen acquisition and utilization, which in turn reduced substance storage because of trade-off in the 300th generation, thus decreasing POC and PON. Interestingly, populations at both elevated temperatures exhibited significant proteome plasticity in the 700th generation, as primarily demonstrated by the increased lipid catabolism and glucose accumulation, accounting for the recovery of POC and PON. Changes occurring in cells at the 300th and 700th generations demonstrate that S. dohrnii can adapt to the projected OW, and readjusting the energy metabolism is an important adaptive strategy.

Molecular insight into coordination sites for substrates and their coupling kinetics in Na+ /HCO3- cotransporter NBCe1.

The secondary active transporter NBCe1 couples the transmembrane movement of Na+ and carbonate species with an apparent stoichiometry of 1Na+ :2HCO3- (the 'influx' mode) or 1Na+ :3HCO3- (the 'efflux' mode). Here, we employed molecular biology, electrophysiology and structural biology approaches to investigate the molecular mechanism for the transport coupling of Na+ and HCO3- in NBCe1. In Xenopus oocytes, decreasing extracellular [HCO3- ] from 66 to 4 mm progressively decreases the Na+ affinity of NBCe1. However, decreasing [Na+ ] from 96 to 35 mm has little effect on the HCO3- affinity. The residues responsible for the coordination of Na+ and HCO3- in the substrate pocket of NBCe1 were respectively determined by mutational and molecular simulation studies. Mutation to the residues for HCO3- coordination decreased the affinities of NBCe1 for both Na+ and HCO3- . However, mutation to the residues for Na+ coordination decreased the affinity for Na+ but had little effect on the affinity for HCO3- . Molecular simulation showed that NBCe1 has the capacity to coordinate only two ions of HCO3- or CO32- . We propose that (1) NBCe1 has an ordered substrate-binding kinetics with the binding of HCO3- preceding that of Na+ ; (2) NBCe1 operating in the influx mode moves 1Na+  + 2HCO3- , whereas NBCe1 in the efflux mode moves 1Na+  + 1HCO3-  + 1CO32- . The substrate-binding kinetics of NBCe1 is distinct from the known kinetics models of many other Na+ -coupled transporters with Na+ binding preceding the driven solute. KEY POINTS: Under physiological conditions, the secondary active transporter NBCe1 can operate in the 'influx' mode with an apparent stoichiometry of 1Na+ :2HCO3- or in the 'efflux' mode with an apparent stoichiometry of 1Na+ :3HCO3- . NBCe1 has an ordered substrate-binding kinetics with HCO3- preceding the binding of Na+ . The kinetics of NBCe1 is distinct from the known kinetics of many other Na+ -driven cotransporters for which the binding of Na+ usually precedes the driven substrate. The residues responsible for the coordination of Na+ and those for carbonate species in the substrate-binding pocket of NBCe1 were determined by mutation and molecular simulation studies. The substrate-binding pocket of NBCe1 contains just two coordination sites for HCO3- or CO32- . It is proposed that NBCe1 in the influx mode moves 1Na+  + 2HCO3- across the plasma membrane, whereas NBCe1 in the efflux mode moves 1Na+ +1HCO3- +1CO32- .

Composition and assembly of the bacterial community in the overlying waters of the coral reef of China's Xisha Islands.

Coral reef ecosystems are one of the most diverse and productive habitats on Earth. Microbes in the reef-overlying waters are key players in maintaining this ecosystem through regulating biogeochemical and ecological processes. However, the composition structure and assembly mechanism of microbial community in the reef-overlying waters remain largely unknown. In the present study, the bacterial communities from the overlying waters of atolls and fringing reefs as well as the surface waters of the adjacent open ocean of the Xisha Islands in the South China Sea were investigated using 16S rRNA high-throughput sequencing combined with a size-fractionation strategy. The results showed that environments of all sampling stations were similar, characterized by an almost complete lack of inorganic nutrients such as nitrogen and phosphorus. Proteobacteria, Cyanobacteria and Bacteroidetes were the dominant phyla, and Synechococcus was most abundant at the genus level in both large fraction (LF; 1.6-200 µm) and small fraction (SF; 0.2-1.6 µm) communities. Only a slight difference in community composition between LF and SF samples was observed. The bacterial communities among the three habitat types showed noticeable differences, and the bacterial composition among the atoll reefs was more varied than that among the fringing reefs. The similarity of bacterial communities significantly declined with the increasing geographic distance, and stochastic processes were more important than deterministic processes in bacterial community assembly. This study sheds lights on the bacterial biodiversity of coral reefs and the importance of stochastic process in structuring bacterial communities.

Metabolic tuning of a stable microbial community in the surface oligotrophic Indian Ocean revealed by integrated meta-omics.

Understanding the mechanisms, structuring microbial communities in oligotrophic ocean surface waters remains a major ecological endeavor. Functional redundancy and metabolic tuning are two mechanisms that have been proposed to shape microbial response to environmental forcing. However, little is known about their roles in the oligotrophic surface ocean due to less integrative characterization of community taxonomy and function. Here, we applied an integrated meta-omics-based approach, from genes to proteins, to investigate the microbial community of the oligotrophic northern Indian Ocean. Insignificant spatial variabilities of both genomic and proteomic compositions indicated a stable microbial community that was dominated by Prochlorococcus, Synechococcus, and SAR11. However, fine tuning of some metabolic functions that are mainly driven by salinity and temperature was observed. Intriguingly, a tuning divergence occurred between metabolic potential and activity in response to different environmental perturbations. Our results indicate that metabolic tuning is an important mechanism for sustaining the stability of microbial communities in oligotrophic oceans. In addition, integrated meta-omics provides a powerful tool to comprehensively understand microbial behavior and function in the ocean. Supplementary Information: The online version contains supplementary material available at 10.1007/s42995-021-00119-6.

Initial-position-driven opposite directional transport of a water droplet on a wedge-shaped groove.

The transport direction of water droplets on a functionalized surface is of great significance due to its wide applications in microfluidics technology. The prevailing view is that a water droplet on a wedge-shaped groove always moves towards the wider end. In this paper, however, molecular dynamics simulations show that a water droplet can move towards the narrower end if placed at specific positions. It is found that the direction of water droplet transport on a grooved surface is related to its initial position. The water droplet moves towards the wider end only when it is placed near the wider end initially. If the water droplet is placed near the narrower end, it will move in the opposite direction. The novel phenomenon is attributed to the opposite interactions of the groove substrate and the groove upper layers with water droplets. Two effective models are proposed to exploit the physical origin of different transport directions of water droplets on a wedge-shaped groove surface. The study provides an insight into the design of nanostructured surfaces to effectively control the droplet motion.

Polysaccharide utilization by a marine heterotrophic bacterium from the SAR92 clade.

SAR92 is one of the few examples of a widely distributed, abundant oligotroph that can be cultivated to study pathways of carbon oxidation in ocean systems. Genomic evidence for SAR92 suggests that this gammaproteobacterium might be a primary consumer of polysaccharides in the epipelagic zone, its main habitat. Here, we investigated cell growth, polysaccharide utilization gene expression, and carbohydrate-active enzyme abundance of a culturable SAR92 strain, HTCC2207, grown with different polysaccharides. Xylan and laminarin, two polysaccharides mainly produced by phytoplankton, supported the growth of HTCC2207 better than other polysaccharides. HTCC2207 possessed polysaccharide utilization loci (PULs) consisting of TonB-dependent receptor (TBDR) and glycoside hydrolase (GH) family genes. GH genes such as GH17 and GH3 presented no substrate-specificity and were induced by different sugar substrates, while expressions of GH16, GH10 and GH30 were enhanced in the glucose-treatment but suppressed in the polysaccharide-treatment, indicating complex polysaccharide utilization by HTCC2207. Metabolic pathways for laminarin and xylan were re-constructed in HTCC2207 based on the PULs genes and other predicted carbohydrate-active enzymes. This study reveals features of the epipelagic niche of SAR92 and provide insight into the biogeochemical cycling of labile, high-molecular carbohydrate compounds in the surface ocean.

Illuminating Key Microbial Players and Metabolic Processes Involved in the Remineralization of Particulate Organic Carbon in the Ocean's Twilight Zone by Metaproteomics.

The twilight zone (from the base of the euphotic zone to the depth of 1,000 m) is the major area of particulate organic carbon (POC) remineralization in the ocean, and heterotrophic microbes contribute to more than 70% of the estimated remineralization. However, little is known about the microbial community and metabolic activity directly associated with POC remineralization in this chronically understudied realm. Here, we characterized the microbial community proteomes of POC samples collected from the twilight zone of three contrasting sites in the Northwest Pacific Ocean using a metaproteomic approach. The particle-attached bacteria from Alteromonadales, Rhodobacterales, and Enterobacterales were the primary POC remineralizers. Hydrolytic enzymes, including proteases and hydrolases, that degrade proteinaceous components and polysaccharides, the main constituents of POC, were abundant and taxonomically associated with these bacterial groups. Furthermore, identification of diverse species-specific transporters and metabolic enzymes implied niche specialization for nutrient acquisition among these bacterial groups. Temperature was the main environmental factor driving the active bacterial groups and metabolic processes, and Enterobacterales replaced Alteromonadales as the predominant group under low temperature. This study provides insight into the key bacteria and metabolic processes involved in POC remineralization, and niche complementarity and species substitution among bacterial groups are critical for efficient POC remineralization in the twilight zone. IMPORTANCE The ocean's twilight zone is a critical zone where more than 70% of the sinking particulate organic carbon (POC) is remineralized. Therefore, the twilight zone determines the size of biological carbon storage in the ocean and regulates the global climate. Prokaryotes are major players that govern remineralization of POC in this region. However, knowledge of microbial community structure and metabolic activity is still lacking. This study unveiled microbial communities and metabolic activities of POC samples collected from the twilight zone of three contrasting environments in the Northwest Pacific Ocean using a metaproteomic approach. Alteromonadales, Rhodobacterales, and Enterobacterales were the major remineralizers of POC. They excreted diverse species-specific hydrolytic enzymes to split POC into solubilized POC or dissolved organic carbon. Temperature played a crucial role in regulating the community composition and metabolism. Furthermore, niche complementarity or species substitution among bacterial groups guaranteed the efficient remineralization of POC in the twilight zone.

Metaproteomics Reveals Similar Vertical Distribution of Microbial Transport Proteins in Particulate Organic Matter Throughout the Water Column in the Northwest Pacific Ocean.

Solubilized particulate organic matter (POM) rather than dissolved organic matter (DOM) has been speculated to be the major carbon and energy sources for heterotrophic prokaryotes in the ocean. However, the direct evidence is still lack. Here we characterized microbial transport proteins of POM collected from both euphotic (75 m, deep chlorophyll maximum DCM, and 100 m) and upper-twilight (200 m and 500 m) zones in three contrasting environments in the northwest Pacific Ocean using a metaproteomic approach. The proportion of transport proteins was relatively high at the bottom of the euphotic zone (200 m), indicating that this layer was the most active area of microbe-driven POM remineralization in the water column. In the upper-twilight zone, the predicted substrates of the identified transporters indicated that amino acids, carbohydrates, taurine, inorganic nutrients, urea, biopolymers, and cobalamin were essential substrates for the microbial community. SAR11, Rhodobacterales, Alteromonadales, and Enterobacteriales were the key contributors with the highest expression of transporters. Interestingly, both the taxonomy and function of the microbial communities varied among water layers and sites with different environments; however, the distribution of transporter types and their relevant organic substrates were similar among samples, suggesting that microbial communities took up similar compounds and were functionally redundant in organic matter utilization throughout the water column. The similar vertical distribution of transport proteins from the euphotic zone to the upper twilight zone among the contrasting environments indicated that solubilized POM rather than DOM was the preferable carbon and energy sources for the microbial communities.

Electric field-induced gas dissolving in aqueous solutions.

Gas dissolution or accumulation regulating in an aqueous environment is important but difficult in various fields. Here, we performed all-atom molecular dynamics simulations to study the dissolution/accumulation of gas molecules in aqueous solutions. It was found that the distribution of gas molecules at the solid-water interface is regulated by the direction of the external electric field. Gas molecules attach and accumulate to the interface with an electric field parallel to the interface, while the gas molecules depart and dissolve into the aqueous solutions with a vertical electric field. The above phenomena can be attributed to the redistribution of water molecules as a result of the change of hydrogen bonds of water molecules at the interface as affected by the electric field. This finding reveals a new mechanism of regulating gas accumulation and dissolution in aqueous solutions and can have tremendous applications in the synthesis of drugs, the design of microfluidic device, and the extraction of natural gas.

Draft Genome Sequences of Nine Cultivable Heterotrophic Proteobacteria Isolated from Phycosphere Microbiota of Toxic Alexandrium catenella LZT09.

Microscopic interactions between phycosphere microbiota and host algae play crucial roles in aquatic ecosystems. Despite their significance, there is a scarcity of available genome sequences derived from the phycosphere microbiome. Here, we report the draft genome sequences of nine heterotrophic proteobacterial strains isolated from the toxic dinoflagellate Alexandrium catenella LZT09 during execution of our Phycosphere Microbiome Project. Further exploration of the genomic features of the alga-associated bacterial community will profoundly help in deeply deciphering the processes and mechanisms governing the host-microbe interactome within algal holobionts in the ocean.