First-Principles Study of Bimetallic Pairs Embedded on Graphene Co-Doped with N and O for N2 Electroreduction.

The electrocatalytic nitrogen reduction reaction (NRR) is considered a viable alternative to the Haber-Bosch process for ammonia synthesis, and the design of highly active and selective catalysts is crucial for the industrialization of the NRR. Dual-atom catalysts (DACs) with dual active sites offer flexible active sites and synergistic effects between atoms, providing more possibilities for the tuning of catalytic performance. In this study, we designed 48 graphene-based DACs with N4O2 coordination (MM'@N4O2-G) using density functional theory. Through a series of screening strategies, we explored the reaction mechanisms of the NRR for eight catalysts in depth and revealed the "acceptance-donation" mechanism between the active sites and the N2 molecules through electronic structure analysis. The study found that the limiting potential of the catalysts exhibited a volcano-shaped relationship with the d-band center of the active sites, indicating that the synergistic effect between the bimetallic components can regulate the d-band center position of the active metal M, thereby controlling the reaction activity. Furthermore, we investigated the selectivity of the eight DACs and identified five potential NRR catalysts. Among them, MoCo@N4O2-G showed the best NRR performance, with a limiting potential of -0.20 V. This study provides theoretical insights for the design and development of efficient NRR electrocatalysts.

Hymenobacter endophyticus sp. nov., isolated from wheat leaf tissue.

A bacterium, designated strain ZK17L-C2T, was isolated from the leaf tissues of wheat (Triticum aestivum) collected in Chengdu, Sichuan Province, PR China. It is aerobic, non-motile, Gram-negative, rod-shaped and red-to-pink in colour. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain ZK17L-C2T belonged to the genus Hymenobacter and was most closely related to Hymenobacter rigui KCTC 12533T (98.68 %) and Hymenobacter metallilatus 9PBR-2T (98.19 %). Digital DNA-DNA hybridization (dDDH) values between strain ZK17L-C2T and these two type strains were 26.6 and 26.5 %, and average nucleotide identity (ANI) values were 84.9 and 84.8 %, respectively; these values are lower than the proposed and generally accepted species boundaries for dDDH and ANI. The genomic DNA G+C content of strain ZK17L-C2T was 59.4 mol%. It can grow at pH 5.5-7.5 and 15-30 °C, which is different from the closely related type strains. The major fatty acids of strain ZK17L-C2T were iso-C15 : 0, C16 : 0 and C18 : 0. Overall, the results from biochemical, chemical taxonomy and phylogenetic analyses indicate that strain ZK17L-C2T (=CGMCC 1.19373T=KCTC 92184 T) represents a new species of the genus Hymenobacter, for which the name Hymenobacter endophyticus sp. nov. is proposed.

NEDD4 activates mitophagy by interacting with LC3 to restrain reactive oxygen species and apoptosis in Apostichopus japonicus challenged with Vibrio splendidus.

Mitophagy, the selective degradation of damaged mitochondria by autophagy, plays a crucial role in the survival of coelomocytes in Apostichopus japonicus following Vibrio splendidus infection by suppressing the generation of reactive oxygen species (ROS) and attenuating cell apoptosis. A recent study revealed that reducing the expression of the neural precursor cell-expressed developmentally downregulated gene 4 (NEDD4), an enzyme 3 (E3) ubiquitin ligase, significantly affects mitochondrial degradation. Prior to the present study, the functional role of NEDD4 in marine invertebrates was largely unexplored. Therefore, we investigated the role of NEDD4 in the activation of mitophagy, modulation of ROS levels, and induction of apoptosis in A. japonicus infected with V. splendidus. The results demonstrated that V. splendidus infection and lipopolysaccharide (LPS) challenge significantly increased the mRNA levels of NEDD4 in A. japonicus coelomocytes, which was consistent with changes in mitophagy under the same conditions. Knockdown of AjNEDD4 using specific small interfering RNAs (siRNAs) impaired mitophagy and caused accumulation of damaged mitochondria, as observed using transmission electron microscopy (TEM) and confocal microscopy. Furthermore, AjNEDD4 was localized to the mitochondria in both coelomocytes and HEK293T cells. Simultaneously, coelomocytes were treated with the inhibitor indole-3-carbinol (I3C) to confirm the regulatory role of AjNEDD4 in mitophagy. The accumulation of AjNEDD4 in the mitochondria and the level of mitophagy decreased. Subsequent investigations demonstrated that AjNEDD4 interacts directly with the microtubule-associated protein light chain 3 (LC3), a key regulator of autophagy and mitophagy, indicating its involvement in the mitophagy pathway. Moreover, AjNEDD4 interference hindered the interaction between AjNEDD4 and LC3, thereby impairing the engulfment and subsequent clearance of damaged mitochondria. Finally, AjNEDD4 interference led to a significant increase in intracellular ROS levels, followed by increased apoptosis. Collectively, these findings suggest that NEDD4 acts as a crucial regulator of mitophagy in A. japonicus and plays a vital role in maintaining cellular homeostasis following V. splendidus infection. NEDD4 suppresses ROS production and subsequent apoptosis by promoting mitophagy, thereby safeguarding the survival of A. japonicus under pathogenic conditions. Further investigation of the mechanisms underlying NEDD4-mediated mitophagy may provide valuable insights into the development of novel strategies for disease control in aquaculture farms.

Molecular cloning and characterization of endoplasmic reticulum stress related genes grp78 and atf6α from black seabream (Acanthopagrus schlegelii) and their expressions in response to nutritional regulation.

Glucose-regulated protein 78 (grp78) and activating transcription factor 6α (atf6α) are considered vital endoplasmic reticulum (ER) molecular chaperones and ER stress (ERS) sensors, respectively. In the present study, the full cDNA sequences of these two ERS-related genes were first cloned and characterized from black seabream (Acanthopagrus schlegelii). The grp78 cDNA sequence is 2606 base pair (bp) encoding a protein of 654 amino acids (aa). The atf6α cDNA sequence is 2168 base pair (bp) encoding a protein of 645 aa. The predicted aa sequences of A. schlegelii grp78 and atf6α indicated that the proteins contain all the structural features, which were characteristic of the two genes in other species. Tissues transcript abundance analysis revealed that the mRNAs of grp78 and atf6α were expressed in all measured tissues, but the highest expression of these two genes was all recorded in the gill followed by liver/ brain. Moreover, in vivo experiment found that fish intake of a high lipid diet (HLD) can trigger ERS by activating grp78/Grp78 and atf6α/Atf6α. However, it can be alleviated by dietary betaine supplementation, similar results were also obtained by in vitro experiment using primary hepatocytes of A. schlegelii. These findings will be beneficial for us to evaluate the regulator effects of HLD supplemented with betaine on ERS at the molecular level, and thus provide some novel insights into the functions of betaine in marine fish fed with an HLD.

Genome-wide identification m6A modified circRNAs revealed their key roles in skin ulceration syndrome disease development in Apostichopus japonicus.

Circular RNAs (circRNAs) are novel endogenous non-coding RNAs (ncRNAs) and can be acted as competing endogenous RNAs (ceRNAs) to regulate microRNA (miRNA) and downstream gene expression. Recently, m6A modification has been found in circRNA, and m6A circRNAs also play important roles in various biological processes and a variety of diseases. Our previous study had been demonstrated that circRNAs were differentially expressed in skin ulceration syndrome (SUS) diseased sea cucumber Apostichopus japonicus. However, whether the function of circRNAs are dependent on m6A levels are largely unknown. Here, we firstly investigated the genome-wide map of m6A circRNAs in sea cucumbers with different stages of Vibrio splendidus challenge, that's Control group, SUS-diseased group, and SUS-resistant group. MeRIP-seq revealed that m6A abundances were enriched in circRNAs in all three groups, especially for SUS-resistant group. Among them, more than 62% of modified circRNAs harbor only a single m6A peak and about 55% of m6A sites in circRNAs were derived from sense overlapping in each group. After V. splendidus infection, we found that most of m6A peaks in circRNAs were upregulated and less were downregulated in both SUS-diseased and SUS-resistant groups when compared with Control. Furthermore, GO analysis indicated that the host genes of circRNAs with dysregulated m6A peaks in SUS-diseased and SUS-resistant groups were both mainly enriched in the adhesion pathway. More importantly, we discovered that more than 50% m6A circRNAs showed a positive correlation between the circRNAs expression and m6A methylation levels both in SUS-diseased and SUS-resistant groups. Therefore, a core circRNA-miRNA-mRNA (ceRNA) network whether influenced by m6A modification was constructed based on conjoint analysis. Our results indicated that several selected m6A circRNAs bind with miRNAs were mainly targeting to ubiquitylation system and adhesion pathway. What's more, three candidate m6A circRNAs and three target genes were validated by MeRIP-qPCR and qPCR, whose m6A levels in circRNA and mRNA expressions were consistent with disease occurrence or disease resistance. All of our current findings suggested that m6A circRNAs could play important roles during pathogen infection and might be served as a new molecular biomarker in SUS disease diagnose of A. japonicus.

Multi-Level Features Extraction for Discontinuous Target Tracking in Remote Sensing Image Monitoring.

Many techniques have been developed for computer vision in the past years. Features extraction and matching are the basis of many high-level applications. In this paper, we propose a multi-level features extraction for discontinuous target tracking in remote sensing image monitoring. The features of the reference image are pre-extracted at different levels. The first-level features are used to roughly check the candidate targets and other levels are used for refined matching. With Gaussian weight function introduced, the support of matching features is accumulated to make a final decision. Adaptive neighborhood and principal component analysis are used to improve the description of the feature. Experimental results verify the efficiency and accuracy of the proposed method.

Comparative transcriptome analysis of Sinonovacula constricta in gills and hepatopancreas in response to Vibrio parahaemolyticus infection.

The razor clam Sinonovacula constricta is an important economic species in China. However, bacterial pathogenic diseases limits S. constricta farming industry for large-scale production. In this study, de novo transcriptome sequencing was performed on S. constricta gills and hepatopancreas under Vibrio parahaemolyticus challenge for 12 h and 48 h, respectively. Transcripts assembly constructed 18,330 sequences, each of which was 500 bp long and functionally annotated, and 1781 and 490 transcripts were differentially expressed in the gills and hepatopancreas, respectively. Host immune factors that respond to Vibrio infection were then identified. These factors included up-regulated transcripts with function in non-self recognition, signal transduction, immune effectors and anti-apoptosis. The comparison between the differentially expressed transcripts of the gills and hepatopancreas indicated that immune responses had tissue specificity. As an important external barrier between the environment and the clam, ATP-binding cassette transporters and other ion transporters contribute to immune response in gills, while, transcripts in complement system, such as complement 1 q protein, IgGFc-binding protein, and low affinity immunoglobulin epsilon Fc receptor, were more active in hepatopancreas and often not expressed in gill tissues. Eleven genes were selected to be validated by qRT-PCR and the expressions were consistent with the results of RNA-seq. Our study is the first attempt to identify molecular features in different tissues of S. constricta in response to V. parahaemolyticus infection. These findings improved our understanding of bivalve immunity and defense mechanisms and revealed more potential immune-related genes.

Molecular cloning and functional characterization of theta class glutathione S-transferase from Apostichopus japonicus.

Glutathione S-transferases (GSTs) are the superfamily of multifunctional detoxification isoenzymes and play crucial roles in innate immunity. In the present study, a theta class GST homology was identified from A. japonicus (designated as AjGST-θ) by RACE approaches. The full-length cDNA of AjGST-θ was of 1013 bp encoded a cytosolic protein of 231 amino acids residues. Structural analysis revealed that AjGST-θ processed the characteristic N-terminal GSH-binding site (G-site) and the C-terminal hydrophobic substrate binding site (H-site). Multiple sequence alignment and phylogenetic analysis together supported that AjGST-θ belonged to a new member of theta class GST protein subfamily. Spatial expression analysis revealed that AjGST-θ was ubiquitously expressed in all examined tissues with the larger magnitude in intestine. The Vibrio splendidus challenge in vivo and LPS stimulation in vitro could both significantly up-regulate the mRNA expression of AjGST-θ when compared with control group. The recombinant protein was expressed in Escherichia coli and the purified AjGST-θ showed high activity with GST substrate. Meantime, disc diffusion assay showed that recombinant AjGST-θ protein could markedly improve bacterial growth under Cumene hydroperoxide exposure. More importantly, the recombinant AjGST-θ could effectively prevent primary coelomocytes apoptosis after LPS exposure. Our present findings suggested that AjGST-θ might play significantly roles in the modulation of immune response and protect cells from pathogens infection in A. japonicus.

Molecular cloning and functional characterization of cathepsin B from the sea cucumber Apostichopus japonicus.

Cathepsin B (CTSB), a member of lysosomal cysteine protease, is involved in multiple levels of physiological and biological processes, and also plays crucial roles in host immune defense against pathogen infection in vertebrates. However, the function of CTSB within the innate immune system of invertebrates, particularly in marine echinoderms, has been poorly documented. In this study, the immune function of CTSB in Apostichopus japonicus (designated as AjCTSB), a commercially important and disease vulnerable aquaculture specie, was investigated by integrated molecular and protein approaches. A 2153 bp cDNA representing the full-length of AjCTSB was cloned via overlapping ESTs and RACE fragments. AjCTSB contained an open reading frame of 999 bp encoding a secreted protein of 332 amino acid residues with a predicted molecular mass of 36.8 kDa. The deduced amino acid of AjCTSB shared a typical activity center containing three conserved amino acid residues (Cys108, His277 and Asn297). Phylogenetic tree analysis also supported that AjCTSB was a new member of CTSB family with clustering firstly with invertebrate CTSBs. Quantitative real time PCR analysis revealed that AjCTSB was ubiquitously expressed in all examined tissues with the highest levels in intestine. The Vibrio splendidus challenged sea cucumber and LPS-exposed coelomocytes could both significantly boost the expression of AjCTSB. Moreover, the purified recombinant AjCTSB exhibited dose-dependent CTSB activities at the concentration ranged from 0 to 0.24 µg µL-1. Further functional analysis indicated that coelomocytes apoptosis was significantly inhibited by 0.16-fold in vivo and the apoptosis execution Ajcaspase 3 was extremely reduced in Apostichopus japonicus coelomocytes treated with specific AjCTSB siRNA. Collectively, all these results suggested that AjCTSB was an important immune factor and might be served as apoptosis enhancers in pathogen challenged sea cucumber.

Characterization of NLRP3-like gene from Apostichopus japonicus provides new evidence on inflammation response in invertebrates.

Inflammatory/defensive response after pathogen invasion is considered a local defense reaction in vertebrates. Inflammation response in Apostichopus japonicus was hardly determined due to scarce information available for nucleotide binding domain-like receptor family, pyrin domain-containing (NLRP) family. In the present study, invertebrate NLRP homologue was identified from A. japonicus (designated as AjNLRP3-like) by rapid amplification of cDNA ends. Full-length cDNA of AjNLRP3-like measured 2970 bp with 2265 bp open reading frame encoding a 754-amino acid (aa) residue protein. Structural analysis revealed that AjNLRP3-like processed characteristic domains of pyrin (32-102aa) and NACHT (183-339aa). Multiple sequence alignment and phylogenetic analysis supported that AjNLRP3-like belongs to a new member of NLRP3 protein subfamily. Spatial expression analysis revealed that AjNLRP3-like was ubiquitously expressed in all examined tissues with larger magnitude in coelomocytes. Both Vibrio splendidus challenge in vivo and lipopolysaccharide stimulation in vitro significantly upregulated mRNA expression of AjNLRP3-like when compared with the control group. NLRP3-mediated inflammation response depended on release of lysosomal cathepsin B (CTSB) and subsequent activation of high-mobility group box (HMGB) in vertebrates. We investigated expression profiles of AjNLRP3-like and AjHMGB after AjCTSB knock-down and discovered that AjNLRP3-like was depressed by 0.66-fold and 0.47-fold, whereas AjHMGB was depressed by 0.70-fold and 0.50-fold at 24 and 48 h in AjCTSB-silenced group, respectively. Similarly, down-regulation of AjHMGB was also observed after AjNLRP3-like knock-down. This study therefore suggests that A. japonicus feature similar inflammatory events as those in vertebrates, and activation of AjNLRP3-like depends on AjCTSB expression and release of AjHMGB.

A novel platform self-assembled from squaraine-embedded Zn(ii) complexes for selective monitoring of ATP and its level fluctuation in mitotic cells.

Using multiple interactions, a simple self-assembly based on a Zn(ii) coordination compound and squaraine () demonstrated a selective turn-on fluorescence response to ATP in the near infrared (NIR) region. More importantly, the self-assembly has been successfully applied to ATP imaging in the mitochondria of the gastric cancer cell line SGC-7901 and monitoring of level fluctuation of ATP during the mitotic period.

Molecular cloning and characterization of four caspases members in Apostichopus japonicus.

The caspase family representing aspartate-specific cysteine proteases have been demonstrated to possess key roles in apoptosis and immune response. We previously demonstrated that LPS challenged Apostichopus japonicus coelomocyte could significantly induced apoptosis in vitro. However, apoptosis related molecules were scarcely investigated in this economic species. In the present work, we cloned and characterized four members caspase family from A. japonicus (designated as Ajcaspase-2, Ajcaspase-3, Ajcaspase-6, and Ajcaspase-8, respectively) by RACE. Multiple sequence alignment and structural analysis revealed that all Ajcaspases contained the conservative CASC domain at C terminal, in which some unique features for each Ajcaspase made them different from each other. These specific domains together with phylogenetic analysis supported that all these four identified proteins belonged to novel members of apoptotic signaling pathway in sea cucumber. Tissue distribution analysis revealed that four Ajcaspase genes were constitutively expressed in all examined tissues. The expression of Ajcaspase-2 was tightly correlated with that of Ajcaspase-8 in each detected tissues. Ajcaspase-3 and Ajcaspase-6 transcripts were both highly expressed in immune tissue of coelomocytes. Furthermore, the Vibrio splendidus challenged sea cucumber coelomocytes could significantly up-regulate the mRNA expressions of four genes. The expression levels of Ajcaspase-2 and Ajcaspase-8 were relative earlier than those of Ajcaspase-6 and Ajcaspase-3, respectively, which could be inferred that Ajcapase-2 might directly modulate Ajcaspase-6, and Ajcaspase-8 initiate the expression of Ajcaspase-3. The induce expressions differed among each Ajcaspase depending upon their roles such as initiator or effector caspase. All our results demonstrated that four Ajcaspases present diversified functions in apoptotic cascade signaling pathway of sea cucumber under immune response.

RNA-seq analysis revealed ROS-mediated related genes involved in cadmium detoxification in the razor clam Sinonovacula constricta.

The razor clam Sinonovacula constricta is a eukaryotic benthic intertidal bivalve species that is tolerant to different heavy metals, such as cadmium ion (Cd(2+)). However, the mechanism by which S. constricta responds to Cd(2+)-induced stress remains unclear. In this study, eight transcriptome libraries were constructed and sequenced using razor clams exposed to Cd(2+) for 12 and 48 h. A total of 18,330 unigenes with an average length of 500 bp were annotated. Among these 18,330 unigenes, 582 and 649 displayed differential expression profiles at 12 and 48 h in the gill, respectively. The corresponding differential unigenes in the hepatopancreas were 1056 and 382. Gene Ontology annotation revealed that these unigenes were highly pronounced in metabolic process, cellular process, binding, and catalytic activity. Notably, ROS production-related genes, such as heat shock proteins 32, metallothionein, and glutathione, were synchronously enriched in all experimental samples with induced expression profiles, which was also validated by qPCR. Our results highlighted the relation between immune regulation and Cd(2+)-induced stress in razor clam and provided new insights into the molecular mechanisms of heavy toxicology.

[Construction of SPA7074-deficient mutant of biocontrol strain Streptomyces pactum Act12 and characterization of its secondary metabolites].

Objective: To disrupt spa7074, which encodes a member of the TetR family transcriptional factors, in biocontrol strain Act12 and characterize the secondary metabolites in the mutant strain. Methods: We disrupted the gene spa7074 by homologous recombination. The secondary metabolites of the mutant strain Δspa7074 and Act12 were detected by HPLC. The structure was analyzed by MS and NMR. Results: Compared to the wild-type strain, the production of some unknown compounds in the mutant strain Δspa7074 increased obviously. We purified one of the compounds and identified as oligomycin D by MS and NMR analysis. Conclusion: An oligomycin D-producing strain Δspa7074 was derived via genetic engineering.

Three members in JAK/STAT signal pathway from the sea cucumber Apostichopus japonicus: Molecular cloning, characterization and function analysis.

The JAK/STAT signal transduction pathway plays a critical role in host defense against bacterial infections. In the present study, we firstly cloned the full-length cDNAs of three molecules in JAK/STAT cascade, STAT5, FOXP and SOCS2, from sea cucumber Apostichopus japonicus (denoted as AjSTAT5, AjFOXP, AjSOCS2, respectively) and investigated their immune functions towards Vibrio splendidus infection and LPS exposure. The AjSTAT5 cDNA was composed of 2643 bp consisting of 787 amino acid residues which included protein interaction domain, STAT-α domain, DNA binding domain and SH2 domain. The putative AjFOXP contained a ZnF_C2H2 domain, the leucine zipper-like domain and FH domain, all of which were thought to be the representative characteristics of FOXP subfamily. The deduced amino acids sequence of AjSOCS2 included an SH2 domain and SOCS box domain similar to vertebrate SOCS counterparts. Phylogenetic trees further supported that all these three identified proteins belonged to novel members of JAK/STAT signal pathway in sea cucumber. Tissue specific expression analysis showed that three genes were ubiquitously expressed in all examined tissues. AjSTAT5 and AjFOXP were both dominantly expressed in intestine, tentacle and respiratory tree, and weak in muscle. In contrary, the peak expression of AjSOCS2 was observed in muscle and lowest in respiratory tree. The V. splendidus challenge and LPS exposure could both significantly up-regulate the mRNA expression of three genes, in which AjSOCS2 showed opposite expression trends to those of AjSTAT5 and AjFOXP. Silencing the AjSTAT5 by siRNA depressed the AjFOXP expression, but induced the expression level of AjSOCS2, revealing that AjSTAT5 might directly modulate AjFOXP, and AjSOCS2 function primarily by acting as a potent inhibitor involve in JAK/STAT pathway. The present study would expand our understanding on JAK/STAT signaling transduction pathway in modulating the innate immune responses of sea cucumber.

Adenovirus carrying gene encoding Haliotis discus discus sialic acid binding lectin induces cancer cell apoptosis.

Lectins exist widely in marine bioresources such as bacteria, algae, invertebrate animals and fishes. Some purified marine lectins have been found to elicit cytotoxicity to cancer cells. However, there are few reports describing the cytotoxic effect of marine lectins on cancer cells through virus-mediated gene delivery. We show here that a replication-deficient adenovirus-carrying gene encoding Haliotis discus discus sialic acid binding lectin (Ad.FLAG-HddSBL) suppressed cancer cell proliferation by inducing apoptosis, as compared to the control virus Ad.FLAG. A down-regulated level of anti-apoptosis factor Bcl-2 was suggested to be responsible for the apoptosis induced by Ad.FLAG-HddSBL infection. Further subcellular localization studies revealed that HddSBL distributed in cell membrane, ER, and the nucleus, but not in mitochondria and Golgi apparatus. In contrast, a previously reported mannose-binding lectin Pinellia pedatisecta agglutinin entered the nucleus as well, but did not distribute in inner membrane systems, suggesting differed intracellular sialylation and mannosylation, which may provide different targets for lectin binding. Further cancer-specific controlling of HddSBL expression and animal studies may help to provide insights into a novel way of anti-cancer marine lectin gene therapy. Lectins may provide a reservoir of anti-cancer genes.

Mechanisms for the Enhancement of Caproic Acid and H2 Production in Ruminococcaceae Bacterium CPB6 by Fe(II) and Mg(II): Growth and Gene Transcription Analyses.

The production of caproic acid (CA) and hydrogen gas (H2) from organic wastewater is economically attractive. The Ruminococcaceae bacterium CPB6 has demonstrated potential for CA production from lactate-containing wastewater. However, our understanding of the effects of Fe2+ and Mg2+ on the growth and metabolism of strain CPB6 remains limited. Therefore, this study aims to investigate the impact of Fe2+ and Mg2+ on CA and H2 production, as well as on the expression of key genes involved in CA and H2 biosynthesis pathway. The results indicate that Fe2+ positively affects cell proliferation and H2 production while minimally impacting CA production. The highest levels of H2 production were achieved with the addition of 200 mg/L Fe2+. Conversely, Mg2+ significantly enhances CA and H2 production, with the optimal yield observed in a medium enriched with 300 mg/L Mg2+. Reverse transcription quantitative PCR (RT-qPCR) analysis reveals that Fe2+ promotes the expression of the hydrogenase gene, whereas Mg2+ has a negligible effect on hydrogenase expression. Notably, Fe2+ and Mg2+ inhibit the expression of key genes involved in CA synthesis. These findings suggest that Fe2+ enhances H2 production by boosting cell biomass and the expression of the hydrogenase gene, whereas Mg2+ improves CA and H2 production primarily by increasing cell biomass rather than influencing the expression of functional genes involved in CA biosynthesis.

Isolation, characterization and application of a lytic phage vB_VspM_VS1 against Vibrio splendidus biofilm.

Vibrio splendidus is a common pathogen in the ocean that infects Apostichopus japonicus, Atlantic salmon and Crassostrea gigas, leading to a variety of diseases. In this study, a virulent phage vB_VspM_VS1, which infects V. splendidus, was isolated from aquaculture ponds in Dalian, China, and it belongs to the family Straboviridae in the order Caudoviricetes. vB_VspM_VS1 had an adsorption rate of 96% in 15 min, a latent period of 65 min, and a burst size of 140 ± 6 PFU/cell. The complete genome of phage vB_VspM_VS1 consists of a linear double-stranded DNA that is 248,270 bp in length with an average G + C content of 42.5% and 389 putative protein-coding genes; 116 genes have known functions. There are 4 tail fiber genes in the positive and negative strands of the phage vB_VspM_VS1 genome. The protein domain of the phage vB_VspM_VS1 tail fibers was obtained from the Protein Data Bank and the SMART (http://smart.embl.de) database. Bacterial challenge tests revealed that the growth of V. splendidus HS0 was apparently inhibited (OD600 < 0.01) in 12 h at an MOI of 10. In against biofilms, we also showed that the OD570 value of the vB_VspM_VS1-treated group (MOI = 1) decreased significantly to 0.04 ± 0.01 compared with that of the control group (0.48 ± 0.08) at 24 h. This study characterizes the genome of the phage vB_VspM_VS1 that infects the pathogenic bacterium V. splendidus of A. japonicus.

Synthesis and photophysical properties of phosphorus(V) porphyrins functionalized with axial carbazolylvinylnaphthalimides.

We have synthesized new D-A-D type phosphorus(V) porphyrin derivatives and functionalized with axial carbazolylvinylnaphthalimide units. The absorption bands of the obtained phosphorus(V) porphyrins were in the range 250-640 nm with high molar absorption coefficients, meaning strong light-harvesting abilities. Notably, it is found that the devices based on phosphorus(V) porphyrins with a configuration structure of [ITO/PEDOT : PSS/organic active film/LiF/Al] give an incident-photon-to-current conversion efficiency (IPCE) response. The maximal IPCE value reaches 2.76% for the device based on compound , which is much higher than that of 0.20% for compound . The reason might be due to the low oxidation potential and the strong light-harvesting ability of the enlarged conjugation of the axial units in compound . Therefore, we deduced that photo-induced electron transfer happened in phosphorus(V) porphyrins bearing axial conjugated donor units, which would make them good candidates for photovoltaic materials that could be applied in solar cells.

Corrigendum: CircRNA75 and CircRNA72 Function as the Sponge of MicroRNA-200 to Suppress Coelomocyte Apoptosis Via Targeting Tollip in Apostichopus japonicus.

[This corrects the article DOI: 10.3389/fimmu.2021.770055.].