Search

Abstract Background Bacteria, Archaea, and Microeukaryotes comprise taxonomic domains that interact in mediating biogeochemical cycles in coastal waters. Many studies have revealed contrasting biogeographic patterns of community structure and assembly mechanisms in microbial communities from different domains in coastal ecosystems; however, knowledge of specific biogeographic patterns on microbial co-occurrence relationships across complex coastal environmental gradients remains limited. Using a dense sampling scheme at the regional scale, SSU rRNA gene amplicon sequencing, and network analysis, we investigated intra- and inter-domain co-occurrence relationships and network topology-based biogeographic patterns from three microbial domains in coastal waters that show environmental gradients across the inshore-nearshore-offshore continuum in the East China Sea. Results Overall, we found the highest complexity and connectivity in the bacterial network, the highest modularity in the archaeal network, and the lowest complexity, connectivity, and modularity in the microeukaryotic network. Although microbial co-occurrence networks from the three domains showed distinct topological features, they exhibited a consistent biogeographic pattern across the inshore-nearshore-offshore continuum. Specifically, the nearshore zones with intermediate levels of terrestrial impacts reflected by multiple environmental factors (including water temperature, salinity, pH, dissolved oxygen, and nutrient-related parameters) had a higher intensity of microbial co-occurrence for all three domains. In contrast, the intensity of microbial co-occurrence was weaker in both the inshore and the offshore zones at the two ends of the environmental gradients. Archaea occupied a central position in the microbial inter-domain co-occurrence network. In particular, members of the Thaumarchaeota Marine Group I (MGI, now placed within the Family Nitrosopumilaceae of the Phylum Thermoproteota) appeared to be the hubs in the biogeographic shift between inter-domain network modules across environmental gradients. Conclusions Our work offers new insights into microbial biogeography by integrating network features into biogeographic patterns, towards a better understanding of the potential of microbial interactions in shaping biogeographic patterns of coastal marine microbiota.

The Chinese mitten crab (Eriocheir sinensis, CMC) is of significant economic importance to China's aquatic industry. However, the prevalence of Planktothricoides-dominated cyanobacterial blooms (CBs) pose a substantial threat to this aquaculture sector. Despite their impact, there is limited understanding of how these CBs affect the digestive systems of CMCs. This study aims to investigate the effects of CBs dominated by Planktothricoides on CMC growth, intestinal bacterial communities, metabolism, and digestive enzyme activity. Our findings indicate that CBs dominated by Planktothricoides impede CMC growth and significantly alter immune and digestive enzyme activities. Notably, a decline in the richness and Shannon diversity of the intestinal bacterial community were observed, along with shifts in its structure and composition. The abundance of Epsilonbacteraeota, a group containing various conditional pathogens, reached 21.40 % at the family level in the CB group. A total of 26 bacteria were identified as potential pathogens in the CMC intestine. While immune activities demonstrated a strong correlation with potential pathogens, digestive enzyme activities were less correlated. Furthermore, CBs significantly impacted the metabolic pathways in the CMC intestine, leading to a marked reduction in several metabolites involved in lipid metabolism. In conclusion, this study focuses on the impact of CBs in natural environments on the digestive system of CMCs. It fills the knowledge gap regarding the actual negative effects of CBs on CMCs. Urgent interventions are warranted to support the prevention and control of CBs in CMC culture.

In this study, an eight-week culture trial of Penaeus vannamei juveniles was conducted in commercial intensive systems to compare the impacts of biochar and molasses addition on biofloc nitrifying bacteria and inorganic nitrogen dynamics under limited water exchange conditions. During the trial, the biofloc concentration (in terms of VSS and TSS), quantities of total bacteria (TB) and total Vibrio (TV), and ratio of TV/TB in the culture water were lower in the biochar group compared to the molasses group. Metagenomic sequencing analysis revealed that the bacterial community composition of bioflocs showed higher α-diversity and complexity in the biochar group compared to the molasses group. Moreover, the abundance of nitrifying bacterial genera and functional genes in bioflocs was higher in the biochar group compared to the molasses group. Inorganic nitrogen dynamics showed that NH4+-N and NO2−-N were better controlled in the biochar group compared to the molasses group, as reflected by lower peaks of NH4+-N and NO2−-N and higher NO3−-N concentrations. Excellent production performance of shrimp was achieved, which in turn proved the reliable effect of biochar addition on the mediation of inorganic nitrogen transformation through nitrifying bacteria. These results showed that biochar addition could promote biofloc nitrifying bacteria and nitrification to more effectively control harmful nitrogen for shrimp efficient production. This study provides a practical example for the biochar application in biofloc-based systems for intensive aquaculture.

ABSTRACT Skeletonema costatum, a cosmopolitan diatom primarily inhabiting coastal ecosystems, exhibits a typically close yet variable relationship with heterotrophic bacteria. The increasing temperature of surface seawater is expected to substantially affect the viability and ecological dynamics of S. costatum, potentially altering its relationship with bacteria. However, it remains unclear to what extent the elevated temperature could change these relationships. Here, the relationship between axenic S. costatum and natural seawater bacteria underwent a dramatic shift from mutualism to antagonism as the co-culture temperature increased from 20°C to 25°C. The co-occurrence network indicated significantly increased complexity of interaction between S. costatum and bacteria community after temperature elevation, especially with Flavobacteriaceae, implying their potential role in eliminating S. costatum under higher temperatures. Additionally, a Flavobacteriaceae isolate, namely MS1 identified as Tamlana genus, was isolated from the co-culture system at 25°C. MS1 had a remarkable ability to eliminate S. costatum, with the mortality rate at 25°C steadily rising from 30.2% at 48 h to 92.4% at 120 h. However, it promoted algal growth to some extent at 20°C. These results demonstrated that increased temperature promotes MS1 shifts from mutualism to antagonism with S. costatum. According to the comparative genomics analysis, changes in the lifestyle of MS1 were attributed to the increased gliding motility and attachment of MS1 under elevated temperature, enabling it to exert an algicidal effect through direct contact with alga. This investigation provided an advanced understanding of interactions between phytoplankton and bacteria in future warming oceanic ecosystems.IMPORTANCEOcean warming profoundly influences the growth and metabolism of phytoplankton and bacteria, thereby significantly reshaping their interactions. Previous studies have shown that warming can change bacterial lifestyle from mutualism to antagonism with phytoplankton, but the underlying mechanism remains unclear. In this study, we found that high temperature promotes Tamlana sp. MS1 adhesion to Skeletonema costatum, leading to algal lysis through direct contact, demonstrating a transition in lifestyle from mutualism to antagonism with increasing temperature. Furthermore, the gliding motility of MS1 appears to be pivotal in mediating the transition of its lifestyle. These findings not only advance our understanding of the phytoplankton-bacteria relationship under ocean warming but also offer valuable insights for predicting the impact of warming on phytoplankton carbon sequestration.

ABSTRACT Dinoflagellates and diatoms are highly prevalent and ecologically important phytoplankton in coastal waters, greatly contributing to primary productivity in marine ecosystems. Although their composition and diversity have been extensively elucidated in the open ocean, their interaction patterns and community assembly in long-term eutrophic coastal waters remain poorly understood. This investigation aimed to elucidate the seasonal successional patterns of dinoflagellates and diatoms by 18S rRNA gene amplicon sequencing in a semi-enclosed bay. The results revealed that dinoflagellate and diatom communities have pronounced seasonal succession patterns, which are primarily associated with temperature. Furthermore, the most prevalent species throughout the year were Heterocapsa rotundata and Skeletonema costatum. Moreover, the assembly of dinoflagellate and diatom communities was mainly dominated by stochastic processes, with drift being the major factor. The co-occurrence of dinoflagellates and diatoms showed seasonal patterns, with the highest interactions observed in autumn. In addition, interactions of Syndiniales with dinoflagellates and diatoms highlighted the roles of parasites in eutrophic conditions. Flavobacteriaceae and Rhodobacteraceae are the bacterial taxa that most frequently interacted with dinoflagellates and diatoms, with interactions between dinoflagellates and bacteria being more complex than those between diatoms and bacteria. Overall, this study provides results that deepen our understanding of the phytoplankton dynamics in coastal eutrophic waters.IMPORTANCEDinoflagellates and diatoms are major phytoplankton groups in coastal waters. The composition and diversity of dinoflagellates and diatoms in the open ocean have been well documented; however, it remains uncertain to what extent their adaptation to long-term eutrophic conditions influences their response to environmental disturbances. Here, we investigated the interactions and assembly processes of dinoflagellates and diatoms in a eutrophic bay throughout the whole year. Our findings revealed that interactions between dinoflagellates and diatoms are primarily shaped by seasonal transitions, while prolonged eutrophic conditions tend to amplify stochastic processes in community assembly. These findings provide novel perspectives on the influence of long-term eutrophication on phytoplankton dynamics within eutrophic waters.

The primary aim of this paper is to introduce a novel approach to simulating and predicting Marine Comprehensive Carrying Capacity (MCCC), which seeks to enhance the efficacy and accuracy of MCCC assessment and prediction. MCCC is crucial for effective marine resource management and sustainable energy exploitation, as it determines the maximum activities that the marine environment can support without significant degradation. Given the considerable complexity associated with the marine environment and the need for more reliable predictive technologies, this paper proposes an integrated model that combines the capabilities of the proven optimization algorithm, Enhanced Ant Colony, and System Dynamics Modelling. This approach allows for detailed simulation of the variables associated with MCCC, improving prediction precision.The study details the methodology for developing an adapted Ant Colony algorithm and the foundation of a system dynamics model. These models are interconnected within a single framework, tested across multiple scenarios to validate their robustness and sustainability. The results demonstrate the superiority of the proposed approach over conventional models in terms of prediction accuracy and precision, confirmed through both in-sample and out-of-sample validation procedures.This paper is a significant contribution to the fields of sustainability and energy management within marine environments. It provides a new tool for policymakers and environmental managers to enhance their decision-making processes with a greater depth of knowledge, ensuring the sustainable utilization of marine resources and energy potential.

Abstract Background Understanding community assembly mechanisms across taxa and space is fundamental for microbial ecology. However, the variability and determinants of assembly processes over taxa and space remain unclear. Here, we investigated taxonomic dependency and spatial heterogeneity in bacterial assembly mechanisms across coastal waters in the East China Sea using neutral and null models with customized visualization strategies. Results Overall, bacterial assembly mechanisms varied across broad taxonomic groups (phyla and proteobacterial classes) and space at the regional scale. A determinism–stochasticity balanced mechanism governed total bacterial assembly, while taxonomic dependency existed in assembly mechanisms and ecological processes. Among community ecological features, niche breadth and negative-to-positive cohesion ratio were strongly associated with the determinism-to-stochasticity ratio of bacterial groups. Bacterial assembly mechanisms commonly exhibited spatial heterogeneity, the extent and determinants of which varied across taxonomic groups. Spatial assembly of total bacteria was directly driven by many environmental factors and potential interactions between taxa, but not directly by geographic factors. Overall, the bacterial groups with higher spatial heterogeneity in assembly mechanisms were more related to environmental and/or geographic factors (except Bacteroidetes), while those with lower heterogeneity were more related to ecological features. Conclusions Our results confirm the pervasiveness of taxonomic dependency and spatial heterogeneity in bacterial assembly, providing a finer understanding about regulation across complex coastal waters.

Abstract Background Shrimp cultured in a biofloc system (BFS) have a lower disease incidence than those farmed in a water exchange system (WES). Although a number of studies have reported that the gut bacterial community induced by BFS is highly associated with shrimp disease resistance, the causal relationship remains unknown. Here, the promotive roles of gut bacterial community induced by BFS in pathogenic Vibrio infection resistance and its potential micro-ecological and physiological mechanisms were investigated by gut bacterial consortium transplantation and synthetic community (SynCom) construction. Results The BFS induced a more stable and resistant gut bacterial community, and significantly enriched some beneficial bacterial taxa, such as Paracoccus, Ruegeria, Microbacterium, Demequina, and Tenacibaculum. Transplantation of a gut bacterial consortium from BFS shrimp (EnrichBFS) greatly enhanced the stability of the bacterial community and resistance against pathogenic V. parahaemolyticus infection in WES shrimp, while transplantation of a gut bacterial consortium from WES shrimp significantly disrupted the bacterial community and increased pathogen susceptibility in both WES and BFS shrimp. The addition of EnrichBFS in shrimp postlarvae also improved the pathogen resistance through increasing the relative abundances of beneficial bacterial taxa and stability of bacterial community. The corresponding strains of five beneficial bacterial taxa enriched in BFS shrimp were isolated to construct a SynComBFS. The addition of SynComBFS could not only suppress disease development, but also improve shrimp growth, boost the digestive and immune activities, and restore health in diseased shrimp. Furthermore, the strains of SynComBFS well colonized shrimp gut to maintain a high stability of bacterial community. Conclusions Our study reveals an important role for native microbiota in protecting shrimp from bacterial pathogens and provides a micro-ecological regulation strategy towards the development of probiotics to ameliorate aquatic animal diseases. Video Abstract

Abstract Background Archaea are key mediators of estuarine biogeochemical cycles, but comprehensive studies comparing archaeal communities among multiple estuaries with unified experimental protocols during the same sampling periods are scarce. Here, we investigated the distribution, community assembly, and cross-domain microbial co-occurrence of archaea in surface waters across four major estuaries (Yellow River, Yangtze River, Qiantang River, and Pearl River) of China cross climatic zones (~ 1,800 km) during the winter and summer cruises. Results The relative abundance of archaea in the prokaryotic community and archaeal community composition varied with estuaries, seasons, and stations (reflecting local environmental changes such as salinity). Archaeal communities in four estuaries were overall predominated by ammonia-oxidizing archaea (AOA) (aka. Marine Group (MG) I; primarily Nitrosopumilus), while the genus Poseidonia of Poseidoniales (aka. MGII) was occasionally predominant in Pearl River estuary. The cross-estuary dispersal of archaea was largely limited and the assembly mechanism of archaea varied with estuaries in the winter cruise, while selection governed archaeal assembly in all estuaries in the summer cruise. Although the majority of archaea taxa in microbial networks were peripherals and/or connectors, extensive and distinct cross-domain associations of archaea with bacteria were found across the estuaries, with AOA as the most crucial archaeal group. Furthermore, the expanded associations of MGII taxa with heterotrophic bacteria were observed, speculatively indicating the endogenous demand for co-processing high amount and diversity of organic matters in the estuarine ecosystem highly impacted by terrestrial/anthropogenic input, which is worthy of further study. Conclusions Our results highlight the lack of common patterns in the dynamics of estuarine archaeal communities along the geographic gradient, expanding the understanding of roles of archaea in microbial networks of this highly dynamic ecosystem.

Abstract Sucrose is an effective carbon source for creating more reliable and environmentally friendly conditions for shrimp growth by regulating bacteria in biofloc-based culture systems. However, the influence of sucrose addition on the interaction, co-occurrence networks, and assembly mechanisms of bacterial communities in biofloc-based culture systems remains largely unknown. Here, we comprehensively investigated the effects of sucrose addition on bacterial communities in three habitats (water, bioflocs, and gut). The bacterial community structures and compositions of these three habitats became more similar in groups with sucrose addition, compared with those in controls. More than 50% gut bacterial communities were mainly derived from water and biofloc communities in the sucrose addition groups, but only about 33% bacterial communities migrated from water and biofloc to the gut in the control culture system. Sucrose addition accordantly enriched core taxa belonging to the phylum Actinobacteria and the families Rhodobacteraceae and Flavobacteriaceae in water, biofloc, and gut habitats. These core taxa were important for maintaining bacterial network stability in the sucrose addition culture systems and some were identified as keystone taxa for improving shrimp growth. Furthermore, after sucrose addition, gut bacterial community assembly from water and biofloc was dominated by the heterogeneous select with the ratios of 55–91% and 67–83%, respectively, indicating that sucrose addition can directionally shape the bacterial assembly of the shrimp culture system. These results provide a basis for selectively regulating certain beneficial taxa to improve shrimp growth in culture systems.

Background: As one of the most common autoimmune diseases, myasthenia gravis (MG) severely affects the quality of life of patients. Therefore, exploring the role of dysregulated genes between MG and healthy controls in the diagnosis of MG is beneficial to reveal new and promising diagnostic biomarkers and clinical therapeutic targets.Methods: The GSE85452 dataset was downloaded from the Gene Expression Omnibus (GEO) database and differential gene expression analysis was performed on MG and healthy control samples to identify differentially expressed genes (DEGs). The functions and pathways involved in DEGs were also explored by functional enrichment analysis. Significantly associated modular genes were identified by weighted gene co-expression network analysis (WGCNA), and MG dysregulated gene co-expression modular-based diagnostic models were constructed by gene set variance analysis (GSVA) and least absolute shrinkage and selection operator (LASSO). In addition, the effect of model genes on tumor immune infiltrating cells was assessed by CIBERSORT. Finally, the upstream regulators of MG dysregulated gene co-expression module were obtained by Pivot analysis.Results: The green module with high diagnostic performance was identified by GSVA and WGCNA. The LASSO model obtained NAPB, C5orf25 and ERICH1 genes had excellent diagnostic performance for MG. Immune cell infiltration results showed a significant negative correlation between green module scores and infiltration abundance of Macrophages M2 cells.Conclusion: In this study, a diagnostic model based on the co-expression module of MG dysregulated genes was constructed, which has good diagnostic performance and contributes to the diagnosis of MG.

Coastal areas are highly influenced by terrestrial runoffs and anthropogenic disturbances, commonly leading to ecological gradients from bay, nearshore, to offshore areas. Although the occurrence and distribution of sediment antibiotic resistome are explored in various coastal environments, little information is available regarding geographic patterns and determinants of coastal sediment antibiotic resistomes across ecological gradients at the regional scale. Here, using high-throughput quantitative PCR, we investigated the geographic patterns of 285 antibiotic resistance genes (ARGs) in coastal sediments across a ~ 200 km scale in the East China Sea. Sediment bacterial communities and physicochemical properties were characterized to identify the determinants of sediments antibiotic resistome. Higher richness and abundance of ARGs were detected in the bay samples compared with those in nearshore and offshore samples, and significant negative correlations between the richness and/or abundance of ARGs and the distance to coastline (DTC) were identified, whereas different types of ARGs showed inconsistency in their relationships with DTC. The composition of antibiotic resistome showed significant correlations with nutrition-related variables (including NH4+-N, NO3−-N, and total phosphorus) and metals/metalloid (including As, Cu, Ni, and Zn), suggesting that terrestrial disturbances largely shape the antibiotic resistome. The Bipartite network showed strong associations between ARGs and mobile genetic elements (MGEs), and Partial Least Squares Path Modeling further revealed that terrestrial disturbance strength (as indicated by DTC) directly affected abiotic environmental conditions and bacterial community composition, and indirectly affected antibiotic resistome via MGEs. These findings provide insights into regional variability of sediment antibiotic resistome and its shaping path across complex ecological gradients, highlighting terrestrial disturbances as determinative forces in shaping coastal sediment antibiotic resistomes.

Intestinal bacterial communities play an important role in the growth and health of aquatic animal hosts and have drawn increasing attention. However, the role of the intestinal microbiota in the growth of freshwater prawns remains unclear. Here, the intestinal microbiota of freshwater prawns (Macrobrachium rosenbergii) at different life stages (one, two, and three months old) were investigated using 16S rRNA sequencing. The results showed that community richness and diversity increased with growth, which might be one of the reasons that the prawns maintained a fast growth rate before sexual maturation. Three core phyla were identified in the one-month-old group, namely, Firmicutes (79.24%), Proteobacteria (17.09%) and Actinobacteriota (2.01%). Five core phyla were identified in the two-month-old group, including Firmicutes (47.84%), Proteobacteria (44.22%), Actinobacteriota (1.83%), Acidobacteriota (1.66%) and Bacteroidota (1.24%), and the core phyla in the three-month-old group were similar, except for Acidobacterota, which was not identified. A total of 12 core genera were identified in all samples, and significant differences were observed in the relative abundance of gut microbiota between the three groups (p < 0.05). Exiguobacterium, Lactococcus and Shewanella were the three most significantly differentially abundant genera between stages. In addition, Candidatus Hepatoplasma was detected only in the two- and three-month-old prawn groups. This study provides information on the differences in the intestinal microbiota in different developmental stages, which contribute to adaptation to salinity in the early developmental stage and digestive ability to meet the growth needs of Macrobrachium rosenbergii.

ABSTRACT Eutrophication occurring in coastal bays is prominent in impacting local ecosystem structure and functioning. To understand how coastal bay ecosystem function responds to eutrophication, comprehending the ecological processes associated with microbial community assembly is critical. However, quantifying the contribution of ecological processes to the assembly of prokaryotic communities is still limited in eutrophic waters. Moreover, the influence of these ecological processes on microbial interactions is poorly understood. Here, we examined the assembly processes and co-occurrence patterns of prokaryotic communities in a eutrophic bay using 156 surface seawater samples collected over 12 months. The variation of prokaryotic community compositions (PCCs) could be mainly explained by environmental factors, of which temperature was the most important. Under high environmental heterogeneity conditions in low-temperature seasons, heterogeneous selection was the major assembly process, resulting in high β-diversity and more tightly connected co-occurrence networks. When environmental heterogeneity decreased in high-temperature seasons, drift took over, leading to decline in β-diversity and network associations. Microeukaryotes were found to be important biological factors affecting PCCs. Our results first disentangled the contribution of drift and microbial interactions to the large unexplained variation of prokaryotic communities in eutrophic waters. Furthermore, a new conceptual model linking microbial interactions to ecological processes was proposed under different environmental heterogeneity. Overall, our study sheds new light on the relationship between assembly processes and co-occurrence of prokaryotic communities in eutrophic waters. IMPORTANCE A growing number of studies have examined roles of microbial community assembly in modulating community composition. However, the relationships between community assembly and microbial interactions are not fully understood and rarely tested, especially in eutrophic waters. In this study, we built a conceptual model that links seasonal microbial interactions to ecological processes, which has not been reported before. The model showed that heterogeneous selection plays an important role in driving community assembly during low-temperature seasons, resulting in higher β-diversity and more tightly connected networks. In contrast, drift became a dominant force during high-temperature seasons, leading to declines in the β-diversity and network associations. This model could function as a new framework to predict how prokaryotic communities respond to intensified eutrophication induced by climate change in coastal environment.

ABSTRACT: Wulong geese are renowned for their egg-laying and reproductive abilities. This work investigated the potential of using body size traits in the selection and breeding of high-yielding Wulong geese. A total of forty 479day-old female geese (high-yielding geese, n = 20; low-yielding geese, n = 20) were selected to evaluate the relationship between body weight, body size trait indicators, serum reproductive hormones, and biochemical indicators. The results showed that serum estradiol (E2), glucose (GLU), and triglyceride (TG) concentrations, together with pubic spacing and abdominal circumference were significantly higher in high-yielding geese (P < 0.01), whereas the opposite was true for neck circumference, neck length, and tibial circumference. In addition, the serum testosterone (T) concentration and body weight were higher in high-yielding geese (P < 0.05). Neck circumference and neck length were negatively correlated with E2 and TG (P < 0.01); while pubic spacing and abdominal circumference were positively correlated with E2, GLU, and TG (P < 0.01), the highest correlation coefficient was 0.777 between TG and pubic spacing; T was also strongly associated with neck circumference (P < 0.01). In conclusion, high-yielding Wulong geese can be selected through neck circumference, neck length, pubic spacing, and abdominal circumference.

Heat cooking of meat gives it a specific taste and flavor which are favored by many consumers. While the characteristic taste components of chicken, duck, pig, and seafood have been studied, there is a lack of information about the molecular components that give donkey meat its unique taste. Here, the characterization profiles of raw donkey meat (RDM) and cooked donkey meat (CDM) meat by metabonomics and lipidomics. The results showed that a total of 186 metabolites belonging to 8 subclasses were identified in CDM and RDM, including carbohydrates (27.42%), amino acids (17.20%), lipids (13.44%), and nucleotides (9.14%). In total, 37 differential metabolites were identified between CDM and RDM. Among these, maltotriose, L-glutamate, and L-proline might predominantly contribute to the unique umami and sweet taste of donkey meat. Comprehensive biomarker screening detected 9 potential metabolite markers for the discrimination among RDM and CDM, including L-glutamate, gamma-aminobutyric acid, and butane-1, 2, 3, 4-tetrol. Moreover, a total of 992 and 1,022 lipids belonging to 12 subclasses were identified in RDM and CDM, respectively, mainly including triglycerides (TGs) and glycerophospholipids (GPs). Of these lipids, 116 were significantly different between CDM and RDM. The abundances of 61 TGs rich in saturated and monounsaturated fatty acids were retained in CDM, whereas the abundances of 37 GPs rich in polyunsaturated fatty acids were reduced, suggesting that TGs and GPs might be the predominant lipids for binding and generating aroma compounds, respectively. A total of 13 lipids were determined as potential markers for the discrimination among RDM and CDM, including PC(O-16:2/2:0), LPE(22:5/0:0), and PC(P-16:0/2:0). In conclusion, this study provided useful information about the metabolic and lipid profiles of donkey meat which may explain its unique taste and flavor, which could serve as a basis for the development and quality control of donkey meat and its products.

In this study, we aimed to determine the complete mitochondrial genome of blacktip shark Carcharhinus limbatus. The mitochondrial genome was 16,705 bp in length, including 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and a control region. Phylogenetic analysis was done using the Bayesian inference method, which showed a close relationship between C. limbatus and C. amblyrhynchoides.

The detection of SF6 insulation gas decomposition components in gas-insulated switchgear (GIS) is essential for assessing the GIS operating status and ensuring equipment safety. In this study, we explored the adsorption of SF6 major decomposition products (SO2, SOF2, and SO2F2) on Pt and N co-doped graphene (PtN3-GN) using density functional theory (DFT) calculations. The adsorption structure, energy, and charge transfer of the three adsorbed gases on the PtN3-GN surface were investigated. Gas adsorption results showed that PtN3-GN has a high adsorption capacity for these gas molecules, and adsorption energies are -2.55, -2.54, and -3.54 eV, respectively. To explore the interaction mechanism between gas molecules and the PtN3-GN structure, the total and partial densities of states of the system before and after gas adsorption were compared and analyzed. PtN3-GN strongly interacts with gas molecules, leading to high orbital hybridization between the Pt dopant and gas molecules. PtN3-GN has good adsorption performance for gas molecules and has good application prospects in GIS decomposition component detection and fault diagnosis. [ABSTRACT FROM AUTHOR]

Gut bacterial communities play a crucial role in shrimp growth and health. However, these communities are still vulnerable to pressures (such as high temperatures) that hinder their functions. Here, shrimps were cultured for 6 weeks at three different temperatures: a variable temperature (control group, falling from 23.7 to 20.8°C with ambient temperature) and two fixed temperatures (26 and 30°C) to study their effects on growth, enzyme activity and gut microbes of shrimp. The results indicated that increasing temperature significantly decreased the survival rate of shrimp but had a significant rise in shrimp growth performances with the higher phosphatase enzyme activities than control group. Although the high temperature did not change the alpha diversity indexes of the bacterial communities, their compositions were significantly different, compared with that of control group. The relative abundances of the top 10 families showed a discrepancy in the dominance of the bacterial community, represented by Vibrionaceae and Mycoplasmataceae at 26 and 30°C groups, and Rhodobacteraceae and Flavobacteriaceae in the control group. These results indicate that temperature changes mainly affected the compositions of bacterial community, which increased the susceptibility of shrimp to some pathogenic bacterial species, such as Vibrio, thus leading to a low survival rate of shrimp. [ABSTRACT FROM AUTHOR]