DNA-QLC: an efficient and reliable image encoding scheme for DNA storage.

BACKGROUND: DNA storage has the advantages of large capacity, long-term stability, and low power consumption relative to other storage mediums, making it a promising new storage medium for multimedia information such as images. However, DNA storage has a low coding density and weak error correction ability. RESULTS: To achieve more efficient DNA storage image reconstruction, we propose DNA-QLC (QRes-VAE and Levenshtein code (LC)), which uses the quantized ResNet VAE (QRes-VAE) model and LC for image compression and DNA sequence error correction, thus improving both the coding density and error correction ability. Experimental results show that the DNA-QLC encoding method can not only obtain DNA sequences that meet the combinatorial constraints, but also have a net information density that is 2.4 times higher than DNA Fountain. Furthermore, at a higher error rate (2%), DNA-QLC achieved image reconstruction with an SSIM value of 0.917. CONCLUSIONS: The results indicate that the DNA-QLC encoding scheme guarantees the efficiency and reliability of the DNA storage system and improves the application potential of DNA storage for multimedia information such as images.

Engineering Modular DNA Reaction Networks for Signal Processing.

Diversified molecular information-processing methods have significant implications for nanoscale manipulation and control, monitoring and disease diagnosis of organisms, and direct intervention in biological activities. However, as an effective approach for implementing multifunctional molecular information processing, DNA reaction networks (DRNs) with numerous functionally specialized molecular structures have challenged them on scale design, leading to increased network complexity, further causing problems such as signal leakage, attenuation, and cross-talk in network reactions. Our study developed a strategy for performing various signal-processing tasks through engineering modular DRNs. This strategy is based on a universal core unit with signal selection capability, and a time-adjustable signal self-resetting module is achieved by combing the core unit and self-resetting unit, which improves the time controllability of modular DRNs. In addition, multi-input and -output signal cross-catalytic and continuously adjustable signal delay modules were realized by combining core and threshold units, providing a flexible, precise method for modular DRNs to process the signal. The strategy simplifies the design of DRNs, helps generate design ideas for large-scale integrated DRNs with multiple functions, and provides prospects in biocomputing, gene regulation, and biosensing.

Storing Images in DNA via base128 Encoding.

Current DNA storage schemes lack flexibility and consistency in processing highly redundant and correlated image data, resulting in low sequence stability and image reconstruction rates. Therefore, according to the characteristics of image storage, this paper proposes storing images in DNA via base128 encoding (DNA-base128). In the data writing stage, data segmentation and probability statistics are carried out, and then, the data block frequency and constraint encoding set are associated with achieving encoding. When the image needs to be recovered, DNA-base128 completes internal error correction by threshold setting and drift comparison. Compared with representative work, the DNA-base128 encoding results show that the undesired motifs were reduced by 71.2-90.7% and that the local guanine-cytosine content variance was reduced by 3 times, indicating that DNA-base128 can store images more stably. In addition, the structural similarity index (SSIM) and multiscale structural similarity (MS-SSIM) of image reconstruction using DNA-base128 were improved by 19-102 and 6.6-20.3%, respectively. In summary, DNA-base128 provides image encoding with internal error correction and provides a potential solution for DNA image storage. The data and code are available at the GitHub repository: https://github.com/123456wk/DNA_base128.

Clinical utility of metagenomic next-generation sequencing on bronchoalveolar lavage fluid in diagnosis of lower respiratory tract infections.

BACKGROUND: In this study, we aimed to evaluate the clinical utility of Metagenomic Next-Generation sequencing (mNGS) on bronchoalveolar lavage fluid (BALF) in diagnosis of Lower Respiratory Tract Infections (LRTIs). METHODS: In this study, we retrospectively analyzed 186 hospitalized patients who were suspected with LRTIs and performed mNGS (DNA) test of BALF simultaneously at The Fifth Affiliated Hospital of Sun Yat-Sen University from March 2023 to August 2023. Suspected LRTI was based on LRTI related clinical manifestations or imaging examination. Among them, 155 patients had undergone conventional culture and mNGS (DNA) testing simultaneously. Finally, 138 cases (89.03%,138/155) were diagnosed as LRTI and 17 cases (10.97%,17/155) were diagnosed as non-LRTI. Both detecting rate and diagnostic efficacy of mNGS and conventional culture were compared. RESULTS: The positive detection rates of pathogens between mNGS and conventional culture were significant different (81.29% VS 39.35%, P < 0.05). Compared with paired conventional culture result, the sensitivity of mNGS in diagnosis of LRTIs was more superior (88.41% VS 43.48%; P < 0.05), the specificity was opposite (76.47% VS 94.12%; P > 0.05). Furthermore, 77.54% and 35.51% of LRTI cases were being etiologically diagnosed by mNGS and culture respectively. Importantly, mNGS directly led to a change of treatment regimen in 58 (37.42%) cases, including antibiotic adjustment (29.68%) and ruling out active infection (7.74%). Moreover, treatment regimen remained unchanged in 97 (62.58%) cases, considering the current antibiotic therapy already covered the detected pathogens (36.13%) or empirical treatment was effective (11.61%). CONCLUSIONS: mNGS can identify a wide range of pathogens in LRTIs, with improved sensitivity and being more superior at diagnosing LRTIs etiologically. mNGS has the potential to enhance clinical outcomes by optimizing the treatment regimens.

Transcriptome analysis reveals how cadmium promotes root development and accumulates in Apocynum venetum, a promising plant for greening cadmium-contaminated soil.

Cadmium (Cd) contamination poses a substantial threat the environment, necessitating effective remediation strategies. Phytoremediation emerges as a cost-efficient and eco-friendly approach for reducing Cd levels in the soil. In this study, the suitability of A. venetum for ameliorating Cd-contaminated soils was evaluated. Mild Cd stress promoted seedling and root growth, with the root being identified as the primary tissue for Cd accumulation. The Cd content of roots ranged from 0.35 to 0.55 mg/g under treatment with 10-50 µM CdCl2·2.5 H2O, and the bioaccumulation factor ranged from 28.78 to 84.43. Transcriptome sequencing revealed 20,292 unigenes, and 7507 nonredundant differentially expressed genes (DEGs) were identified across five comparison groups. DEGs belonging to the "MAPK signaling pathway-plant," "monoterpenoid biosynthesis," and "flavonoid biosynthesis pathway" exhibited higher expression levels in roots compared to stems and leaves. In addition, cytokinin-related DEGs, ROS scavenger genes, such as P450, glutathione-S-transferase (GST), and superoxide dismutase (SOD), and the cell wall biosynthesis-related genes, CSLG and D-GRL, were also upregulated in the root tissue, suggesting that Cd promotes root development. Conversely, certain ABC transporter genes, (e.g, NRAMP5), and some vacuolar iron transporters, predominantly expressed in the roots, displayed a strong correlation with Cd content, revealing the mechanism underlying the compartmentalized storage of Cd in the roots. KEGG enrichment analysis of DEGs showed that the pathways associated with the biosynthesis of flavonoids, lignin, and some terpenoids were significantly enriched in the roots under Cd stress, underscoring the pivotal role of these pathways in Cd detoxification. Our study suggests A. venetum as a potential Cd-contaminated phytoremediation plant and provides insights into the molecular-level mechanisms of root development promotion and accumulation mechanism in response to Cd stress.

Ensifer sp. GMS14 enhances soybean salt tolerance for potential application in saline soil reclamation.

Rhizosphere microbiomes play an important role in enhancing plant salt tolerance and are also commonly employed as bio-inoculants in soil remediation processes. Cultivated soybean (Glycine max) is one of the major oilseed crops with moderate salt tolerance. However, the response of rhizosphere microbes me to salt stress in soybean, as well as their potential application in saline soil reclamation, has been rarely reported. In this study, we first investigated the microbial communities of salt-treated and non-salt-treated soybean by 16S rRNA gene amplicon sequencing. Then, the potential mechanism of rhizosphere microbes in enhancing the salt tolerance of soybean was explored based on physiological analyses and transcriptomic sequencing. Our results suggested that Ensifer and Novosphingobium were biomarkers in salt-stressed soybean. One corresponding strain, Ensifer sp. GMS14, showed remarkable growth promoting characteristics. Pot experiments showed that GMS14 significantly improved the growth performance of soybean in saline soils. Strain GMS14 alleviated sodium ions (Na+) toxicity by maintaining low a Na+/K+ ratio and promoted nitrogen (N) and phosphorus (P) uptake by soybean in nutrient-deficient saline soils. Transcriptome analyses indicated that GMS14 improved plant salt tolerance mainly by ameliorating salt stress-mediated oxidative stress. Interestingly, GMS14 was evidenced to specifically suppress hydrogen peroxide (H2O2) production to maintain reactive oxygen species (ROS) homeostasis in plants under salt stress. Field experiments with GMS14 applications showed its great potential in saline soil reclamation, as evidenced by the increased biomass and nodulation capacity of GMS14-inoculated soybean. Overall, our findings provided valuable insights into the mechanisms underlying plant-microbes interactions, and highlighted the importance of microorganisms recruited by salt-stressed plant in the saline soil reclamation.

ATXN2-mediated translation of TNFR1 promotes esophageal squamous cell carcinoma via m6A-dependent manner.

N6-methyladenosine (m6A) is the most prevalent RNA modification, and the effect of its dysregulation on esophageal squamous cell carcinoma (ESCC) development remains unclear. Here, by performing transcriptome-wide m6A sequencing in 16 ESCC tissue samples, we identified the key roles of m6A in TNFRSF1A (also known as TNFR1)-mediated MAPK and NF-κB activation in ESCC. Mechanistically, a functional protein involved in m6A methylation, ATXN2, is identified that augments the translation of TNFRSF1A by binding to m6A-modified TNFRSF1A mRNA. Upregulation of the TNFRSF1A protein level, a vital upstream switch for TNFRSF1A-mediated signaling events, activates the NF-κB and MAPK pathways and thus promotes ESCC development. Furthermore, TNFRSF1A m6A modifications and protein levels are upregulated in ESCC, and high levels of TNFRSF1A m6A and protein are correlated with poor ESCC patient survival. These results collectively indicate that the m6A-TNFRSF1A axis is critical for ESCC development and thus may serve as a potential druggable target.

Effect of planting salt-tolerant legumes on coastal saline soil nutrient availability and microbial communities.

Soil salinization is a serious global environmental problem affecting sustainable development of agriculture. Legumes are excellent candidates for the phytoremediation of saline soils; however, how soil microbes mediate the amelioration of coastal saline ecosystems is unknown. In this study, two salt-tolerant legumes, Glycine soja and Sesbania cannabina were planted in coastal saline soil for three years. Soil nutrient availability and microbiota structure (including bacteria, fungi, and diazotrophs) were compared between the phytoremediated soils and control soil (barren land). Planting legumes reduced soil salinity, and increased total carbon, total nitrogen, and NO3--N contents. Among the soil microbiota, some nitrogen-fixing bacteria (e.g., Azotobacter) were enriched in legumes, which were probably responsible for soil nitrogen accumulation. The complexity of the bacterial, fungal, and diazotrophic networks increased significantly from the control to the phytoremediated soils, suggesting that the soil microbial community formed closer ecological interactions during remediation. Furthermore, the dominant microbial functions were chemoheterotrophy (24.75%) and aerobic chemoheterotrophy (21.97%) involved in the carbon cycle, followed by nitrification (13.68%) and aerobic ammonia oxidation (13.34%) involved in the nitrogen cycle. Overall, our findings suggested that G. soja and S. cannabina legumes were suitable for ameliorating saline soils as they decreased soil salinity and increased soil nutrient content, with microorganisms especially nitrogen-fixing bacteria, playing an important role in this remediation process.

Spatiotemporal distribution of bacterial dimethylsulfoniopropionate producing and catabolic genes in the Changjiang Estuary.

The osmolyte dimethylsulfoniopropionate (DMSP) is produced in petagram amounts by marine microorganisms. Estuaries provide natural gradients in salinity and nutrients, factors known to regulate DMSP production; yet there have been no molecular studies of DMSP production and cycling across these gradients. Here, we study the abundance, distribution and transcription of key DMSP synthesis (e.g. dsyB and mmtN) and catabolic (e.g. dddP and dmdA) genes along the salinity gradient of the Changjiang Estuary. DMSP levels did not correlate with Chl a across the salinity gradient. In contrast, DMSP concentration, abundance of bacterial DMSP producers and their dsyB and mmtN transcripts were lowest in the freshwater samples and increased abruptly with salinity in the transitional and seawater samples. Metagenomics analysis suggests bacterial DMSP-producers were more abundant than their algal equivalents and were more prominent in summer than winter samples. Bacterial DMSP catabolic genes and their transcripts followed the same trend of being greatly enhanced in transitional and seawater samples with higher DMSP levels than freshwater samples. DMSP cleavage was likely the dominant catabolic pathway, with DMSP lyase genes being ~4.3-fold more abundant than the demethylase gene dmdA. This is an exemplar study for future research on microbial DMSP cycling in estuary environments.

microRNA-143-3p regulates odontogenic differentiation of human dental pulp stem cells through regulation of the osteoprotegerin-RANK ligand pathway by targeting RANK.

NEW FINDINGS: What is the central question of this study? What is the role of miR-143-3p during human dental pulp stem cell (hDPSC) differentiation. What is the main finding and its importance? miR-143-3p negatively regulates receptor activator of nuclear factor-κB (RANK). RANK ligand (RANKL) binds to RANK and stimulates the development of osteoclasts. Osteoprotegerin (OPG) inhibits the interaction between RANK and RANKL. The OPG-RANKL signalling pathway regulates odontogenic differentiation of hDPSCs. ABSTRACT: Human dental pulp stem cells (hDPSCs) are capable of differentiating into odontoblast-like cells, which secrete reparative dentin after injury, in which the role of microRNA-143-3p (miR-143-3p) has been identified. Therefore, we investigated the mechanism by which miR-143-3p influences odontoblastic differentiation of hDPSCs. The relationship between miR-143-3p and receptor activator of nuclear factor-κB (RANK) was initially identified by bioinformatics prediction and further verified by dual luciferase reporter gene assay. Gain- and loss-of-function analysis with miR-143-3p mimic and miR-143-3p inhibitor was subsequently conducted. Dentin sialophosphoprotein (DSPP), bone sialoprotein (BSP), alkaline phosphatase (ALP), osteocalcin (OCN) and osteopontin (OPN) mRNA levels were then evaluated by RT-qPCR. Osteoprotegerin (OPG), RANK ligand (RANKL), nuclear factor-κB (NF-κB) p65 protein levels and the extent of NF-κB p65 phosphorylation were examined by western blot analysis. Alizarin red staining was performed to assess the mineralization of hDPSCs. Cell apoptosis and cell cycle distribution were determined using flow cytometry. During odontoblastic differentiation of hDPSC, miR-143-3p had high expression, but RANK expression was low. miR-143-3p was found to target RANK, and its inhibition enhanced mineralization and hDPSC apoptosis, while blocking cell cycle entry. At the same time, miR-143-3p inhibition elevated the extent of NF-κB p65 phosphorylation, as well as the expression of RANK, RANKL, DSPP, BSP, ALP, OCN and OPN, while decreasing the OPG level. Silencing RANK had opposite effects on these markers. miR-143-3p regulates odontoblastic differentiation of hDPSCs via the OPG-RANKL pathway that targets RANK. The elucidation of the mechanisms of odontogenic differentiation of hDPSCs may contribute to the development of effective dental pulp repair therapies for the clinical setting.

Glycocaulis profundi sp. nov., a marine bacterium isolated from seawater of the Mariana Trench.

A Gram-stain-negative, strictly aerobic, rod-shaped bacterium, without flagellum and designated ZYF765T, was isolated from seawater sampled at a depth of 4000 m in the Mariana Trench. Strain ZYF765T grew with 1-15 % (w/v) NaCl (optimum, 4 %), at 16-37 °C (28 °C) and at pH 6.0-10.0 (pH 7.0-8.0). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain ZYF765T formed a lineage within the family Hyphomonadaceae, and was distinct from the most closely related species Glycocaulis abyssi, Glycocaulis albus and Glycocaulis alkaliphilus with 16S rRNA gene sequences similarities ranging from 98.42 to 98.63 %. The major respiratory quinone was ubiquinone-10 (Q-10). The polar lipids comprised three unidentified glycolipids, one unidentified aminophospholipid, one unidentified phospholipid and one unidentified aminolipid. The predominant fatty acids (more than 10 % of total fatty acids) were C18 : 1ω7c (46.2 %) and C18 : 0 (14.1 %). The DNA G+C content was 67.7 mol%. On the basis of the results of polyphasic taxonomic analysis, strain ZYF765T is considered to represent a novel species within the genus Glycocaulis, for which the name Glycocaulis profundi sp. nov. is proposed. The type strain is ZYF765T (=JCM 33028T=MCCC 1K03554T).

Vibrio ouci sp. nov. and Vibrio aquaticus sp. nov., two marine bacteria isolated from the East China Sea.

Two Gram-stain-negative, catalase- and oxidase-positive, facultative anaerobic and rod-shaped motile bacteria, designated strains BEI176T and BEI207T, were isolated from seawater collected in the East China Sea. Phylogenetic analysis based on 16S rRNA gene sequences showed that strains BEI176T and BEI207T belonged to the genus Vibrio and were closely related to each other with 98.18 % similarity. The closest phylogenetic relatives of strain BEI176T were Vibrio alginolyticus LMG 4409T (98.85 %) and Vibrio campbellii LMG 11216T (98.81 %), whereas the closest relative of strain BEI207T was Vibrio hepatarius LMG 20362T (98.64 %). The two strains showed growth at different conditions; while strain BEI176T grew at 16-37 °C, pH 5.0-9.5 and 0-7.0 % (w/v) NaCl, the growth of strain BEI207T occurred at 10-37 °C, pH 6.0-9.5 and 1.0-7.0 % (w/v) NaCl. Both strains shared the same major fatty acid components of summed feature 3 (C16 : 1ω7c or C16 : 1ω6c), C16 : 0 and summed feature 8 (C18 : 1ω6c or C18 : 1ω7c). The DNA G+C contents of the assembled genomic sequences were 44.73 and 45.06 mol% for strains BEI176T and BEI207T, respectively. Average nucleotide identity values between the two strains and their reference species were lower than the threshold for species delineation (95-96 %); in silico DNA-DNA hybridization further showed that the two strains had less than 70 % similarity to their relatives. Therefore, two novel Vibrio species are proposed to accommodate them: Vibrioouci sp. nov. (type strain, BEI176T=MCCC 1K03515T=JCM 32690T= KCTC 62616T) and Vibrioaquaticus sp. nov. (type strain, BEI207T=MCCC 1K03516T=JCM 32691T=KCTC 62617T).

Marinobacter salinexigens sp. nov., a marine bacterium isolated from hadal seawater of the Mariana Trench.

A Gram-stain-negative, strictly aerobic, non-motile and rod-shaped bacterium, designated ZYF650T, was isolated from the hadal seawater (9600 m) of the Mariana Trench. Results of phylogenetic analysis based on 16S rRNA gene sequences indicated that ZYF650T formed a lineage within the family Alteromonadaceae that was distinct from the most closely related species Marinobacter mobilis and Marinobacter nitratireducens with 16S rRNA gene sequences similarities of 98.0 and 97.7 %, respectively. Strain ZYF650T showed average nucleotide identity values of 75.7 % with Marinobacter hydrocarbonoclasticus, 73.3 % with Marinobacter mobilis and 79.3 % with Marinobacter nitratireducens, and DNA-DNAhybridization values of 21.5, 21.3 and 22.0 % with M. hydrocarbonoclasticus, M. mobilis and M. nitratireducens, respectively, which were lower than the threshold for species delineation. Strain ZYF650T grew with 0-14 % (w/v) NaCl (optimum, 7-8 %) at a temperature range of 10-45 °C (optimum, 28 °C) and pH 6.0-9.5 (optimum, pH 7.0-8.0). The sole respiratory quinone was ubiquinone-9 (Q-9). The polar lipids in ZYF650T comprised phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, three unidentified polar lipids, two unidentified aminolipids and two phospholipids. The predominant fatty acids (more than 10 % of total fatty acids) were C18 : 1 ω9c (21.9 %), C16 : 0 (21.7 %), C12 : 0 3-OH (14.0 %), C16 : 1 ω9c (13.2 %) and C12 : 0 (12.2 %). The DNA G+C content of strain ZYF650T was 55.6 %. On the basis of polyphasic taxonomic analysis, strain ZY650T is considered to represent a novel specie of the genus Marinobacter in the family Alteromonadaceae, for which the name Marinobacter salinexigens sp. nov. is proposed. The type strain is ZYF650T (=JCM 33013T=MCCC 1K03552T).

DMSP-Producing Bacteria Are More Abundant in the Surface Microlayer than Subsurface Seawater of the East China Sea.

Microbial production and catabolism of dimethylsulfoniopropionate (DMSP), generating the climatically active gases dimethyl sulfide (DMS) and methanethiol (MeSH), have key roles in global carbon and sulfur cycling, chemotaxis, and atmospheric chemistry. Microorganisms in the sea surface microlayer (SML), the interface between seawater and atmosphere, likely play an important role in the generation of DMS and MeSH and their exchange to the atmosphere, but little is known about these SML microorganisms. Here, we investigated the differences between bacterial community structure and the distribution and transcription profiles of the key bacterial DMSP synthesis (dsyB and mmtN) and catabolic (dmdA and dddP) genes in East China Sea SML and subsurface seawater (SSW) samples. Per equivalent volume, bacteria were far more abundant (~ 7.5-fold) in SML than SSW, as were those genera predicted to produce DMSP. Indeed, dsyB (~ 7-fold) and mmtN (~ 4-fold), robust reporters for bacterial DMSP production, were also far more abundant in SML than SSW. In addition, the SML had higher dsyB transcripts (~ 3-fold) than SSW samples, which may contribute to the significantly higher DMSP level observed in SML compared with SSW. Furthermore, the abundance of bacteria with dmdA and their transcription were higher in SML than SSW samples. Bacteria with dddP and transcripts were also prominent, but less than dmdA and presented at similar levels in both layers. These data indicate that the SML might be an important hotspot for bacterial DMSP production as well as generating the climatically active gases DMS and MeSH, a portion of which are likely transferred to the atmosphere.

PIWI-interacting RNA-36712 restrains breast cancer progression and chemoresistance by interaction with SEPW1 pseudogene SEPW1P RNA.

BACKGROUND: Breast cancer is one of the most common malignancies and the major cause of cancer-related death in women. Although the importance of PIWI-interacting RNAs (piRNAs) in cancer has been increasingly recognized, few studies have been explored the functional mechanism of piRNAs in breast cancer development and progression. METHODS: We examined the top 20 highly expressed piRNAs based on the analysis of TCGA breast cancer data in two patient cohorts to test the roles of piRNAs in breast cancer. The effects of piRNA-36,712 on the malignant phenotypes and chemosensitivity of breast cancer cells were detected in vitro and in vivo. MS2-RIP and reporter gene assays were conducted to identify the interaction and regulation among piRNA-36,712, miRNAs and SEPW1P. Kaplan-Meier estimate with log-rank test was used to compare patient survival by different piRNA-36,712 expression levels. RESULTS: We found piRNA-36,712 level was significantly lower in breast cancer than in normal breast tissues and low level was correlated with poor clinical outcome in patients. Functional studies demonstrated that piRNA-36,712 interacts with RNAs produced by SEPW1P, a retroprocessed pseudogene of SEPW1, and subsequently inhibits SEPW1 expression through competition of SEPW1 mRNA with SEPW1P RNA for microRNA-7 and microRNA-324. We also found that higher SEPW1 expression due to downregulation of piRNA-36,712 in breast cancer may suppress P53, leading to the upregulated Slug but decreased P21 and E-cadherin levels, thus promoting cancer cell proliferation, invasion and migration. Furthermore, we found that piRNA-36,712 had synergistic anticancer effects with the paclitaxel and doxorubicin, two chemotherapeutic agents for breast cancer. CONCLUSIONS: These findings suggest that piRNA-36,712 is a novel tumor suppressor and may serve as a potential predictor for the prognosis of breast cancer patients.

Characterization of a Novel N-Acylhomoserine Lactonase RmmL from Ruegeria mobilis YJ3.

Gram-negative bacteria utilize N-acylhomoserine lactones (AHLs) as quorum sensing (QS) signaling molecules for intercellular communication. Cell-to-cell communication depends on cell population density, and AHL-dependent QS is related to the production of multiple genes including virulence factors. Quorum quenching (QQ), signal inactivation by enzymatic degradation, is a potential strategy for attenuating QS regulated bacterial infections. Both Gram-positive and -negative bacteria have QQ enzymes that can degrade AHLs. In our previous study, strain Ruegeria mobilis YJ3, isolated from healthy shrimp, showed strong AHLs degradative activity. In the current study, an AHL lactonase (designated RmmL) was cloned and characterized from Ruegeria mobilis YJ3. Amino acid sequence analysis showed that RmmL has a conserved "HXHXDH" motif and clusters together with lactonase AidC that belongs to the metallo-ß-lactamase superfamily. Recombinant RmmL could degrade either short- or long-chain AHLs in vitro. High-performance liquid chromatography analysis indicated that RmmL works as an AHL lactonase catalyzing AHL ring-opening by hydrolyzing lactones. Furthermore, RmmL can reduce the production of pyocyanin by Pseudomonas aeruginosa PAO1, while for the violacein and the extracellular protease activities by Chromobacterium violaceum CV026 and Vibrio anguillarum VIB72, no significant reduction was observed. This study suggests that RmmL might be used as a therapeutic agent in aquaculture.

Droplet Motion on a Shape Gradient Surface.

We demonstrate a facile method to induce water droplet motion on an wedge-shaped superhydrophobic copper surface combining with a poly(dimethylsiloxane) (PDMS) oil layer on it. The unbalanced interfacial tension from the shape gradient offers the actuating force. The superhydrophobicity critically eliminates the droplet contact line pinning and the slippery PDMS oil layer lubricates the droplet motion, which makes the droplet move easily. The maximum velocity and furthest position of droplet motion were recorded and found to be influenced by the gradient angle. The mechanism of droplet motion on the shape gradient surface is systematically discussed, and the theoretical model analysis is well matched with the experimental results.

Marinicella pacifica sp. nov., isolated from seawater.

A Gram-stain-negative, strictly aerobic, non-motile, non-gliding, oxidase-positive, catalase-positive, rod-shaped bacterium, designated strain sw153T, was isolated from surface seawater of the South Pacific Gyre (39° 19' S 139° 48' W) during Integrated Ocean Drilling Program Expedition 329. Growth occurred at 10-42 °C (optimum 28 °C), in the presence of 1-8 % (w/v) NaCl (optimum 2 %) and at pH 6.0-10.0 (optimum pH 7.5-8.5). The major fatty acids (>10 %) were iso-C15:0 and summed feature 3 (C16:1ω6c and/or C16:1ω7c). The major polar lipids comprised phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylcholine, phosphatidylglycerol, an unidentified polar lipid and an unidentified phospholipid. The major respiratory quinone was ubiquinone-8 (Q-8). The DNA G+C content of strain sw153T was 44.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences placed strain sw153T within the genus Marinicella, class Gammaproteobacteria. The most closely related species was Marinicella litoralis KMM 3900T (96.6 % 16S rRNA gene sequence similarity). Based on the polyphasic analyses in this study, strain sw153T is considered to represent a novel species of the genus Marinicella, for which the name Marinicella pacifica sp. nov. is proposed. The type strain is sw153T (=JCM 18208T=CGMCC 1.12181T).

Aquimarina hainanensis sp. nov., isolated from diseased Pacific white shrimp Litopenaeus vannamei larvae.

One novel Gram-stain-negative, long rod-shaped, non-spore-forming, non-motile, non-flagellated and strictly aerobic strain, designated M124T, was isolated from diseased Pacific white shrimp Litopenaeus vannamei larvae. Growth occurred at 16-37 °C (optimum 28 °C), in the presence of 2-5 % (w/v) NaCl (optimum 3 %) and at pH 7-8 (optimum pH 7). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain M124T belonged to the genus Aquimarina and showed highest sequence similarity to Aquimarina penaei P3-1T (96.4 %). The dominant fatty acids of the isolate were iso-C15 : 0 and iso-C17 : 0 3-OH. The major polar lipids comprised phosphatidylethanolamine, one unknown aminolipid, three unknown phospholipids, two unknown glycolipids and one unknown polar lipid. The major respiratory quinone was menaquinone 6 (MK-6). The DNA G+C content of strain M124T was 33.7 mol%. Based on the polyphasic analyses in this study, strain M124T is considered to represent a novel species of the genus Aquimarina, for which the name Aquimarina hainanensis sp. nov. is proposed. The type strain is M124T ( = KCTC 42423T = MCCC 1K00498T).

Enterovibrio pacificus sp. nov., isolated from seawater, and emended descriptions of Enterovibrio coralii and the genus Enterovibrio.

A Gram-stain-negative, elliptical and facultatively anaerobic strain, designated SW014T, motile by means of a single polar flagellum and positive for poly-ß-hydroxybutyrate accumulation, was isolated from surface seawater of the South Pacific Gyre, during the Integrated Ocean Drilling Program Expedition 329. The strain was able to grow at 10-37 °C (optimum 28 °C). Growth was observed at NaCl concentrations (w/v) of 1-7 % (optimum 3-4 %). The pH range for growth was 7.0-9.0 (optimum pH 8.0). Phylogenetic analysis based on 16S rRNA gene sequences and multilocus sequence analysis indicated that strain SW014T belongs to the genus Enterovibrio within the family Vibrionaceae and is related most closely to Enterovibrio coralii LMG 22228T with 96.3, 83.7, 95.0, 77.1, 84.1 and 85.8 % sequence similarity based on 16S rRNA, recA, rpoA, rpoD, pyrH and ftsZ genes, respectively. The predominant cellular fatty acids were C16 : 1ω7c and/or C16 : 1ω6c, C16 : 0, and C18 : 1ω7c and/or C18 : 1ω6c. The respiratory quinone was ubiquinone-8 (Q-8). The polar lipids of strain SW014T comprised phosphatidylethanolamine, glycolipid, two unidentified aminolipids, two unidentified phospholipids and two unidentified polar lipids. The DNA G+C content was 44.8 mol%. Combining phylogenetic analysis, phenotypic characteristics and chemotaxonomic studies, strain SW014T represents a novel species of the genus Enterovibrio, for which the name Enterovibrio pacificus sp. nov. is proposed. The type strain is SW014T ( = KCTC 42425T = MCCC 1K00500T). Emended descriptions of Enterovibrio coralii and of the genus Enterovibrio are also provided.