Optimization of Ultrasonic-Assisted Extraction, Characterization and Antioxidant and Immunoregulatory Activities of Polysaccharides.

This study aimed to enhance the ultrasonic-assisted extraction (UAE) yield of seawater polysaccharides (APPs) and investigate its structural characteristics and bioactivities. The optimization of UAE achieved a maximum crude polysaccharides yield of 14.78%.

Isolation, Characterization, Moisturization and Anti-HepG2 Cell Activities of a Novel Polysaccharide from .

Polysaccharides from cyanobacteria are extensively reported for their complex structures, good biocompatibility, and diverse bioactivities, but only a few cyanobacterial species have been exploited for the biotechnological production of polysaccharides. According to our previous study, the newly isolated marine cyanobacterium SCSIO-45682 was a good candidate for polysaccharide production. This work provided a systematic study of the extraction optimization, isolation, structural characterization, and bioactivity evaluation of polysaccharides from SCSIO-45682.

Xenobiotic metabolism activity of gut microbiota from six marine species: Combined taxonomic, metagenomic, and in vitro transformation analysis.

The xenobiotic metabolism driven by the gut microbiota significantly regulates the bioavailability and toxic effects of environmental pollutants such as plasticizers on aquatic organisms. However, it is still unknown whether the gut microbiota can exhibit variable metabolic ability across host species and which functional bacteria and genes are involved in xenobiotic transformation. This study investigated the enriched gut microbiota community composition and diversity of in vitro enrichment cultures from 6 marine species, namely, yellowfin seabream (Acanthopagrus latus), thorn fish (Terapon jarbua), shortnose ponyfish (Leiognathus brevirostris), mussel (Perna viridis), prawn (Parapenaeopsis hungerfordi) and crab (Charybdis riversandersoni).

Unveiling spatiotemporal distribution, partitioning, and transport mechanisms of tire additives and their transformation products in a highly urbanized estuarine region.

Numerous tire additives are high-production volume chemicals that are used extensively worldwide. However, their presence and partitioning behavior remain largely unknown, particularly in marine environments. This study is the first to reveal the spatiotemporal distribution, multimedia partitioning, and transport processing of 22 tire additives and their transformation products (TATPs) in a highly urbanized estuary (n = 166).

Advancing the Understanding of Microplastic Weathering: Insights from a Novel Polarized Light Scattering Approach.

Weathering is a significant process that alters the properties of microplastics (MPs) and consequently affects their environmental behaviors. In this study, we introduced a novel approach based on polarized light scattering technique, which offers advantages in terms of rapid, high-throughput, and submicron-sized detection. This technique was successfully applied to characterize the weathered MPs after a 180-day laboratory simulation of coastal environments.

Flavin-Dependent Monooxygenase Kmy13 Mediates Formation of the Carbocyclic System during Kendomycin B Biosynthesis.

Kendomycin B is distinguished from other ansamycins by its unique, fully carbogenic scaffold. We show here that FAD-dependent monooxygenase Kmy13 is solely responsible for installing the rare structural framework; gene disruption/complementation experiments and enzymatic assays are described in detail. Moreover, the compound with a β-keto ester, kendolactone A (), was confirmed as the natural substrate of Kmy13 and a bona fide biosynthetic intermediate en route to kendomycin B.

EmbB and EmbC regulate the sensitivity of to echinomycin.

Treatment of (Mab) infections is very challenging due to its intrinsic resistance to most available drugs. Therefore, it is crucial to discover novel anti-Mab drugs. In this study, we explored an intrinsic resistance mechanism through which Mab resists echinomycin (ECH).

Metabolomic Profiling and Biological Investigation of the Marine Sponge-Derived Fungus sp. SYPUF29 in Response to NO Condition.

Marine-derived fungi are assuming an increasingly central role in the search for natural leading compounds with unique chemical structures and diverse pharmacological properties. However, some gene clusters are not expressed under laboratory conditions. In this study, we have found that a marine-derived fungus sp.

New Sesquiterpenoids from the Mangrove-Derived Fungus sp. as Modulators of Nuclear Receptors.

Four new sesquiterpenoids, talaroterpenes A-D (-), were isolated from the mangrove-derived fungus sp. SCSIO 41412. The structures of compounds - were elucidated through comprehensive NMR and MS spectroscopic analyses.

Two C-Steroids and a New Isocoumarin Metabolite from Mangrove Sediment-Derived Fungus sp. SCSIO 41429.

Two new C-steroids derivatives, cyclocitrinoic acid A () and cyclocitrinoic acid B (), and a new isocoumarin metabolite, (3,4)-6,8-dihydroxy-3,4,5-trimethyl-7-carboxamidelisocoumarin (), together with 12 known compounds (-, -) were isolated from the mangrove-sediment fungus sp. SCSIO 41429. The structures of the new compounds were comprehensively characterized by 1D and 2D NMR, HRESIMS and ECD calculation.

Machine Learning-Driven Discovery and Evaluation of Antimicrobial Peptides from Mucus Proteome.

Marine antimicrobial peptides (AMPs) represent a promising source for combating infections, especially against antibiotic-resistant pathogens and traditionally challenging infections. However, traditional drug discovery methods face challenges such as time-consuming processes and high costs. Therefore, leveraging machine learning techniques to expedite the discovery of marine AMPs holds significant promise.

New Bioactive Polyketides from the Mangrove-Derived Fungus sp. SCSIO 41411.

Three new polyketides, including three ester derivatives (, , and ) and a new natural product, which was a benzoquinone derivative, embelin A (), together with nine known ones ( and -), were isolated from the mangrove-derived fungus sp. SCSIO 41411. Their structures were determined by detailed NMR and MS spectroscopic analyses.

Terpestacin and Its Derivatives: Bioactivities and Syntheses.

Terpestacin (1), fusaproliferin (2), and their derivatives are a class of sesterterpenes featured by a trans-fused 5/15-membered ring skeleton. There are 45 natural products (1, 2, 4-27, 65-83) isolated from various wild fungi (Fusarium sp., Bipolaris sorokiniana, Arthrinium sp.

Integrating Transcriptome and Metabolome Analyses Revealed Salinity Induces Arsenobetaine Biosynthesis in Marine Medaka ().

Marine fish exhibit elevated levels of arsenobetaine (AsB), while the impact and underlying mechanism of salinity on AsB biosynthesis remain inadequately explored. In this study, marine medaka (), typically inhabiting 30‰ high salinity, were gradually acclimated to low salinities of 20, 10, and 0‰. Following acclimation, the fish were exposed to arsenate (As(V)) in their diet for 30 days.

Phenomenological investigation of organic modified cements as biocompatible substrates interfacing model marine organisms.

Organic modification can generally endow inorganic materials with novel and promotional characteristics to fit into new functionalities. In this paper, new cement-based composite materials, with Portland cement as the substrate and polyacrylamide (PAM, alone) and PAM/chitosan as the functional components mixed with cement (bulk modified) or served as the surface coating (surface modified), were prepared and engineered as sampling substrates for biofilm and coral co-culture. In comparison to the bulk modified substrate and pure cement material, the surface modified substrate showed a balanced mechanical property, considering both bending and compressive strengths and distinctive surface features toward facilitating biofilm and coral growth, as characterized by spectroscopic, morphological, mechanical, and biofilm and coral co-culture experiments.

Fed-batch fermentation strategy for efficient welan gum production by Sphingomonas sp. FM01.

Background: As a novel type of extracellular polysaccharide produced by Sphingomonas sp., welan gum has been widely applied in various fields because of its excellent properties. The study has improved the fermentation process.

Long-term alterations of nutrient dynamics and phytoplankton communities in Daya Bay, South China Sea.

Dynamics of phytoplankton in coastal waters is a function of nutrient influx and the present study investigated the trend in nutrient dynamics and phytoplankton abundance of Daya Bay (DB), South China Sea, from 1986 to 2020. Dissolved inorganic nitrogen (DIN), Dissolved inorganic phosphate (DIP) and Silicates were measured. DIN concentration exhibited an increasing trend over the last decades, and it was above the threshold for the phytoplankton growth.

Metabologenomics-Inspired Discovery and Combinatorial Biosynthesis-Based Diversification of Fungal -Glycosylated Depsides.

Through metabologenomics mining, we prioritized SDU 039, a deep-sea sediment-derived fungus producing -glycosylated depsides (-), including seven new species with varying aliphatic chains. Heterologous expression validated the gene cluster, and enzyme assays elucidated the function of glycosyltransferase ExoC. The chemical diversity of -glycosylated depsides is expanded by combinatorial biosynthesis using homologues depside biosynthetic genes and transformation with ExoC and different sugars as substrate.

Comparative Metabolomics Reveals Changes in the Metabolic Pathways of Ampicillin- and Gentamicin-Resistant .

Antibiotic resistance is a major global challenge requiring new treatments and a better understanding of the bacterial resistance mechanisms. In this study, we compared ampicillin-resistant (R-AMP) and gentamicin-resistant (R-GEN) strains with a sensitive strain (ATCC6538) using metabolomics. We identified 109 metabolites; 28 or 31 metabolites in R-AMP or R-GEN differed from those in ATCC6538.