Secondary metabolites from the deep-sea derived fungus Aspergillus terreus MCCC M28183

Aspergillus fungi are renowned for producing a diverse range of natural products with promising biological activities. These include lovastatin, itaconic acid, terrin, and geodin, known for their cholesterol-regulating, anti-inflammatory, antitumor, and antibiotic properties. In our current study, we isolated three dimeric nitrophenyl trans-epoxyamides (1–3), along with fifteen known compounds (4–18), from the culture of Aspergillus terreus MCCC M28183, a deep-sea-derived fungus. The structures of compounds 1–3 were elucidated using a combination of NMR, MS, NMR calculation, and ECD calculation. Compound 1 exhibited moderate inhibitory activity against human gastric cancer cells MKN28, while compound 7 showed similar activity against MGC803 cells, with both showing IC50 values below 10 μM. Furthermore, compound 16 exhibited moderate potency against Vibrio parahaemolyticus ATCC 17802, with a minimum inhibitory concentration (MIC) value of 7.8 μg/mL. This promising research suggests potential avenues for developing new pharmaceuticals, particularly in targeting specific cancer cell lines and combating bacterial infections, leveraging the unique properties of these Aspergillus-derived compounds

Prokaryotic community structure and key taxa in the Arabian Sea’s oxygen minimum zone

Microbial communities within oxygen minimum zones (OMZs) play crucial roles in the marine biogeochemical cycling. Arabian Sea (AS) has one of the largest OMZs among the global oceans, however, knowledge about the microbial ecology of the AS OMZ remained limited. In the present study, 44 water samples collected from six stations across the AS, spanning from the deep chlorophyll maximum (DCM) layer to 4000m depth were analyzed. High-throughput sequencing of 16S rRNA genes revealed the structural diversity of bacterial and archaeal communities, influenced primarily by depth and dissolved oxygen (DO) levels. Distinct community compositions were observed across different oxygen gradients, with shifts in the relative abundance of key taxa. Notably, Desulfosarcinaceae, UBA10353, Nitrospina, SUP05, Sva0996_marine_group, Microtrichaceae, and Nitrosopumilus emerged as bioindicator taxa in the AS hypoxic zones. Co-occurrence network analysis identified SAR324, Alteromonadaceae, and Sphingomonadaceae as keystone taxa. The spatial and depth-wise distribution patterns revealed that Desulfosarcinaceae was predominantly found in the hypoxic zones of the Arabian Sea, whereas UBA10353, Nitrospina, SUP05, Microtrichaceae and SAR324 were ubiquitous across AS, Bay of Bengal (BOB), and Eastern Tropical North Pacific (ETNP) OMZs, with OTU-level niche differentiation observed for the latter two. Functional profiling using FAPROTAX predicted higher metabolic potential for nitrogen and sulfur in the OMZ compared to other layers of the AS. Our findings provide valuable insights into the distribution, structure, and diversity of microbial communities in the AS OMZ, highlighting the ecological roles of key taxa in hypoxic environments. The established sequence database offers a foundation for further research into the complex interactions within these microbial ecosystems

Associations between colorectal cancer risk and dietary intake of tomato, tomato products, and lycopene: evidence from a prospective study of 101,680 US adults

BackgroundPrevious epidemiological studies have yielded inconsistent results regarding the effects of dietary tomato, tomato products, and lycopene on the incidence of colorectal cancer (CRC), possibly due to variations in sample sizes and study designs.MethodsThe current study used multivariable Cox regression, subgroup analyses, and restricted cubic spline functions to investigate correlations between CRC incidence and mortality and raw tomato, tomato salsa, tomato juice, tomato catsup, and lycopene intake, as well as effect modifiers and nonlinear dose-response relationships in 101,680 US adults from the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial.ResultsDuring follow-up 1100 CRC cases and 443 CRC-specific deaths occurred. After adjustment for confounding variables, high consumption of tomato salsa was significantly associated with a reduced risk of CRC incidence (hazard ratio comparing the highest category with the lowest category 0.8, 95% confidence interval 0.65–0.99, p for trend = 0.039), but not with a reduced risk of CRC mortality. Raw tomatoes, tomato juice, tomato catsup, and lycopene consumption were not significantly associated with CRC incidence or CRC mortality. No potential effect modifiers or nonlinear associations were detected, indicating the robustness of the results.ConclusionIn the general US population a higher intake of tomato salsa is associated with a lower CRC incidence, suggesting that tomato salsa consumption has beneficial effects in terms of cancer prevention, but caution is warranted when interpreting these findings. Further prospective studies are needed to evaluate its potential effects in other populations

The impact of immunoglobulin G N-glycosylation level on COVID-19 outcome: evidence from a Mendelian randomization study

BackgroundThe coronavirus disease 2019 (COVID-19) pandemic has exerted a profound influence on humans. Increasing evidence shows that immune response is crucial in influencing the risk of infection and disease severity. Observational studies suggest an association between COVID‐19 and immunoglobulin G (IgG) N-glycosylation traits, but the causal relevance of these traits in COVID-19 susceptibility and severity remains controversial.MethodsWe conducted a two-sample Mendelian randomization (MR) analysis to explore the causal association between 77 IgG N-glycosylation traits and COVID-19 susceptibility, hospitalization, and severity using summary-level data from genome-wide association studies (GWAS) and applying multiple methods including inverse-variance weighting (IVW), MR Egger, and weighted median. We also used Cochran’s Q statistic and leave-one-out analysis to detect heterogeneity across each single nucleotide polymorphism (SNP). Additionally, we used the MR-Egger intercept test, MR-PRESSO global test, and PhenoScanner tool to detect and remove SNPs with horizontal pleiotropy and to ensure the reliability of our results.ResultsWe found significant causal associations between genetically predicted IgG N-glycosylation traits and COVID-19 susceptibility, hospitalization, and severity. Specifically, we observed reduced risk of COVID-19 with the genetically predicted increased IgG N-glycan trait IGP45 (OR = 0.95, 95% CI = 0.92–0.98; FDR = 0.019). IGP22 and IGP30 were associated with a higher risk of COVID-19 hospitalization and severity. Two (IGP2 and IGP77) and five (IGP10, IGP14, IGP34, IGP36, and IGP50) IgG N-glycosylation traits were causally associated with a decreased risk of COVID-19 hospitalization and severity, respectively. Sensitivity analyses did not identify any horizontal pleiotropy.ConclusionsOur study provides evidence that genetically elevated IgG N-glycosylation traits may have a causal effect on diverse COVID-19 outcomes. Our findings have potential implications for developing targeted interventions to improve COVID-19 outcomes by modulating IgG N-glycosylation levels

Sulfur Metabolism of Hydrogenovibrio thermophilus Strain S5 and Its Adaptations to Deep-Sea Hydrothermal Vent Environment

Hydrogenovibrio bacteria are ubiquitous in global deep-sea hydrothermal vents. However, their adaptations enabling survival in these harsh environments are not well understood. In this study, we characterized the physiology and metabolic mechanisms of Hydrogenovibrio thermophilus strain S5, which was first isolated from an active hydrothermal vent chimney on the Southwest Indian Ridge. Physiological characterizations showed that it is a microaerobic chemolithomixotroph that can utilize sulfide, thiosulfate, elemental sulfur, tetrathionate, thiocyanate or hydrogen as energy sources and molecular oxygen as the sole electron acceptor. During thiosulfate oxidation, the strain produced extracellular sulfur globules 0.7–6.0 μm in diameter that were mainly composed of elemental sulfur and carbon. Some organic substrates including amino acids, tryptone, yeast extract, casamino acids, casein, acetate, formate, citrate, propionate, tartrate, succinate, glucose and fructose can also serve as carbon sources, but growth is weaker than under CO2 conditions, indicating that strain S5 prefers to be chemolithoautotrophic. None of the tested organic carbons could function as energy sources. Growth tests under various conditions confirmed its adaption to a mesophilic mixing zone of hydrothermal vents in which vent fluid was mixed with cold seawater, preferring moderate temperatures (optimal 37°C), alkaline pH (optimal pH 8.0), microaerobic conditions (optimal 4% O2), and reduced sulfur compounds (e.g., sulfide, optimal 100 μM). Comparative genomics showed that strain S5 possesses more complex sulfur metabolism systems than other members of genus Hydrogenovibrio. The genes encoding the intracellular sulfur oxidation protein (DsrEF) and assimilatory sulfate reduction were first reported in the genus Hydrogenovibrio. In summary, the versatility in energy and carbon sources, and unique physiological properties of this bacterium have facilitated its adaptation to deep-sea hydrothermal vent environments

Fatigue effects of discontinuous cyclic loading on the mechanical characteristics of sandstone

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Virus diversity and interactions with hosts in deep-sea hydrothermal vents

Background The deep sea harbors many viruses, yet their diversity and interactions with hosts in hydrothermal ecosystems are largely unknown. Here, we analyzed the viral composition, distribution, host preference, and metabolic potential in different habitats of global hydrothermal vents, including vent plumes, background seawater, diffuse fluids, and sediments. Results From 34 samples collected at eight vent sites, a total of 4662 viral populations (vOTUs) were recovered from the metagenome assemblies, encompassing diverse phylogenetic groups and defining many novel lineages. Apart from the abundant unclassified viruses, tailed phages are most predominant across the global hydrothermal vents, while single-stranded DNA viruses, including Microviridae and small eukaryotic viruses, also constitute a significant part of the viromes. As revealed by protein-sharing network analysis, hydrothermal vent viruses formed many novel genus-level viral clusters and are highly endemic to specific vent sites and habitat types. Only 11% of the vOTUs can be linked to hosts, which are the key microbial taxa of hydrothermal habitats, such as Gammaproteobacteria and Campylobacterota. Intriguingly, vent viromes share some common metabolic features in that they encode auxiliary genes that are extensively involved in the metabolism of carbohydrates, amino acids, cofactors, and vitamins. Specifically, in plume viruses, various auxiliary genes related to methane, nitrogen, and sulfur metabolism were observed, indicating their contribution to host energy conservation. Moreover, the prevalence of sulfur-relay pathway genes indicated the significant role of vent viruses in stabilizing the tRNA structure, which promotes host adaptation to steep environmental gradients. Conclusions The deep-sea hydrothermal systems hold untapped viral diversity with novelty. They may affect both vent prokaryotic and eukaryotic communities and modulate host metabolism related to vent adaptability. More explorations are needed to depict global vent virus diversity and its roles in this unique ecosystem

Transcriptome Analysis of Cyclooctasulfur Oxidation and Reduction by the Neutrophilic Chemolithoautotrophic Sulfurovum indicum from Deep-Sea Hydrothermal Ecosystems

Chemolithoautotrophic Campylobacterota are widespread and predominant in worldwide hydrothermal vents, and they are key players in the turnover of zero-valence sulfur. However, at present, the mechanism of cyclooctasulfur activation and catabolism in Campylobacterota bacteria is not clearly understood. Here, we investigated these processes in a hydrothermal vent isolate named Sulfurovum indicum ST-419. A transcriptome analysis revealed that multiple genes related to biofilm formation were highly expressed during both sulfur oxidation and reduction. Additionally, biofilms containing cells and EPS coated on sulfur particles were observed by SEM, suggesting that biofilm formation may be involved in S0 activation in Sulfurovum species. Meanwhile, several genes encoding the outer membrane proteins of OprD family were also highly expressed, and among them, gene IMZ28_RS00565 exhibited significantly high expressions by 2.53- and 7.63-fold changes under both conditions, respectively, which may play a role in sulfur uptake. However, other mechanisms could be involved in sulfur activation and uptake, as experiments with dialysis bags showed that direct contact between cells and sulfur particles was not mandatory for sulfur reduction activity, whereas cell growth via sulfur oxidation did require direct contact. This indirect reaction could be ascribed to the role of H2S and/or other thiol-containing compounds, such as cysteine and GSH, which could be produced in the culture medium during sulfur reduction. In the periplasm, the sulfur-oxidation-multienzyme complexes soxABXY1Z1 and soxCDY2Z2 are likely responsible for thiosulfate oxidation and S0 oxidation, respectively. In addition, among the four psr gene clusters encoding polysulfide reductases, only psrA3B3C3 was significantly upregulated under the sulfur reduction condition, implying its essential role in sulfur reduction. These results expand our understanding of the interactions of Campylobacterota with the zero-valence sulfur and their adaptability to deep-sea hydrothermal environments