Sediment Extracts Research Articles

New Purinyl-Steroid and Other Constituents from the Marine Fungus Penicillium brefeldianum ABC190807: Larvicidal Activities against Aedes aegypti

Mosquitoes historically threatened human health; the major mosquito-related global health issues include malaria, dengue fever, yellow fever, and Zika, as well as several other vector-borne outbreaks. Here, the EtOAc extract of the mangrove sediment fungus Penicillium brefeldianum ABC190807 exerted larvicidal activities against the third instar larvae of Aedes aegypti with an LC50 of 0.089 mg/mL. One new purinyl-steroid (ergosta-4,6,8(14),22-tetraen-3-(6-amino-9H-purin-9-yl) (1)), along with six (2–7) known compounds, were isolated from the EtOAc extract of Penicillium brefeldianum ABC190807. Structures of the compounds were elucidated via 1D/2D NMR and HR-ESI-MS data. Respective spectral data were compared with those of known compounds. Among all compounds whose larvicidal activity against the third instar larvae of Aedes aegypti was evaluated, compounds 2 and 7 showed larvicidal activity with respective LC50 values of 0.452 and 0.337 mg/mL.

The Smart Rivers approach: Spatial quality in flood protection and floodplain restoration projects based on river DNA

AbstractMany river rehabilitation projects have been implemented in the past 30 years, strengthening the natural dynamics and ecology of river systems, while reconciling the functions of flood protection, navigation, sediment extraction, and cultural identity. Still, the planning and design of floodplain projects is subject to debate on how to best follow the “natural” characteristics of specific river stretches, the “DNA of the river.” Unlike many other approaches of integrated river management, this approach entails a design strategy for spatial quality in river floodplain development projects at local and regional level, where the current discharge characteristics of the upstream river basin are taken as given. Starting point is the landscape ecological basis of the river, defining the characteristic (hydro‐morphological) processes and geomorphological/geological structures in each stretch of the river and floodplain area. An in‐depth characterization of these structures and processes helps design floodplains that can accommodate the various river management and development objectives. Often economically strong functions, like flood protection, can be partnered with weaker ones, such as ecosystem restoration. To safeguard spatial quality and sustainability in these integrated projects, the governance aspect is essential. Therefore the Smart Rivers approach addresses both substantial aspects (the “DNA of the River”) as well as procedural and governance elements (called the “Quality Relay”). The principles of the approach are applicable to project design along regulated rivers in densely populated areas all over the world.This article is categorized under: Water and Life > Conservation, Management, and Awareness

Multi-elemental composition and toxicity of bottom sediments from Panama Canal watershed

The Panama Canal is a milestone in the history of interoceanic communication. Despite its importance, environmental data regarding this important ecosystem is scarce. The aim of this work was to quantify trace-element levels in bottom sediments from 11 sites along the Canal watershed using ICP-MS, and in the case of mercury, employing a direct Hg Analyzer. These data were associated with the biological activity of aqueous sediment extracts tested on wild type and mutant strains of Caenorhabditis elegans, measuring physiological and molecular markers. The levels of trace elements in bottom sediments decreased in the order Sr > V > Ba > Cr > Li > Sc > Ce > Ni > Y > Co > Ga > Pb > Rb > Nd > La > Gd > Dy > Sm > Pr > Er > Hf > Yb > U > Th > Eu > Ho > Be > Tb > Tm > Ta > Hg. The Pollution factor and Pollution Load Index showed that 36% of the sites presented strong sediment pollution by V, Li, Pb, and Sr. Moreover, the Comprehensive Ecological Risk Index based on Cr and Ni levels was exceeded in all stations. Toxicity tests revealed that sediment extracts, despite not being highly lethal against C. elegans, did significantly reduce its mobility and activated toxicity mechanisms associated with the expression of metallothionein and oxidative stress-related genes. These last three endpoints were statistically related to Cr, Ta and Ba concentrations in sediments, respectively. Data suggest elements present in sediments from Panama Canal may be impacting benthonic organisms, and therefore, stronger management regulations should be considered in order to ensure its sustainability.

Chemical composition, antiproliferative and antioxidant attributes of ethanolic extract of resinous sediment from Etlingera elatior (Jack.) inflorescence

The ethanolic extract of resinous sediment (EERS) of Etlingera elatior young inflorescence was examined for its anticancer effect and potential antioxidant activity. The anticancer effect of the EERS was evaluated on four human cancer cell lines, HCT 116, HT-29, Hela, and MCF-7, using the MTT assay. GC-MS analysis showed that the main components found in the EERS were nonyl cyclopropane (4.44%), 1-tetradecane (3.66%), cyclotetradecane (2.41%), cyclododecane (1.92%), and 1-decene (1.72%). The antioxidant activity was determined through different methods. High amounts of TPC and TFC in the EERS were found. Moderate antioxidant capacity of the EERS was detected by DPPH and ABTS assays, with EC50 values of 44.19 and 56.61 μg/mL and a high FRAP value of 281.79 nmol Fe+2 equivalent/mg extract. In the MTT assay, the EERS showed potent anticancer activity, with IC50 values of 19.82, 37.001, 50.49, and 53.29 μg/mL against HT-29, HCT 116, Hela, and MCF-7 tumour cell lines, respectively. Moreover, the results were comparable to or less potent than the standard reference drug, 5-fluorouracil. The results showed that the EERS of Etlingera elatior inflorescence contained a high amount of polyphenols and flavonoids, which may to the selective antiproliferative effects towards colon cancer in vitro

Octyl 6-O-hexanoyl-β-D-glucopyranosides: Synthesis, PASS, antibacterial, in silico ADMET, and DFT studies

An analytical procedure for the analysis of carotenoids in marine sediments rich in organic matter has been developed. Analysis of these compounds is difficult; the application of methods used by other authors required optimization for the samples studied here. The analytical procedure involved multiple ultrasound-assisted extraction with acetone followed by liquid-liquid extraction (acetone extract:benzene:water - 15:1:10 v/v/v) and HPLC analysis. The influence of column temperature on pigment separation and the quantification method were investigated – a temperature of 5 °C was selected for the Lichrospher 100 RP-18e column. The pigments in the sediment extract were quantified using a method based on HPLC analysis (at 450 nm) and spectrophotometric measurements (at 450 nm), and extinction coefficients were determined for standard solutions at this wavelength. It is very important to use the value of the extinction coefficient appropriate to the wavelength at which the detection of carotenoids was carried out.

Microplastic extraction from sediments established? - A critical evaluation from a trace recovery experiment with a custom-made density separator.

By now, microplastics are present in every environmental compartment of which sediments are considered one major sink. As a result, several approaches for their enrichment from sediments have been established in microplastic analysis. At the same time, the smaller microplastics gained increasing attention regarding their ecotoxicological relevance. A customized sediment separator was evaluated with trace amounts of small microplastic particles (150-300 μm) of the nine most common polymers. Separation was performed with sodium bromide (ρ = 1.5 g cm-3). The experimental recovery comprises pristine as well as incubated polymers to include early biofouling effects. Polymer quantification was achieved exclusively using pyrolysis-gas chromatography-mass spectrometry. The results reflected an overall mean recovery of 65%. Interestingly, the observed behaviour seems to be density related. While polymers of higher densities revealed higher average extraction efficiencies (74-97%), those of less dense polymers are reduced and span between 34 and 65%. These observations hypothesize possible polarity related surface interactions as a relevant factor for microplastic particle extraction. In contrast, the density of the separation fluid seemed to be of subordinate relevance, if small microplastic particles were extracted in trace amounts. Early biofouling enhanced recoveries of some polar polymers, whereas the effect on apolar polymers was even negative in some cases. In a comparative synopsis with other published density separation approaches, a limited number of comparable experimental setups concerning particle size, polymer density range and polymer concentration were revealed. Nonetheless, some related experiments point to similar density/polarity driven extraction behaviour. In conclusion, the presented study suggests a re-evaluation of current separation approaches for extraction of low number/mass concentrations of small microplastics from sediments to enable a more comprehensive insight into factors that influence surface properties for microplastics extraction. Concurrently, it raises the question of how an ideal environment relevant recovery experiment can be designed.

Extraction and study of Intracellular compounds of sedimentary wine yeast - waste product of wine production

The present work describes the results of research of a complex of substances obtained from sedimentary wine yeast by extraction with food extractants with the use of ultrasound. The filtrates of alcoholic extracts of yeast and sediments isolated from filtrate were investigated. It has been shown that hydrophobic substances moderately soluble and poorly soluble in alcohol, such as ethyl esters of fatty acids, fatty acids, phospholipids, sterols, squalene, were isolated from sedimentary wine yeast by extraction with alcohol-containing extractants. The mechanical effect of ultrasound provides faster and more complete penetration of the solvent into the intracellular substances. Ultrasound allows one to achieve greater penetration of the solvent into plant tissues and improve mass exchange. Ultrasonic waves, causing cavitation in the liquid, destroy cell walls and promote the release of cell matrix components. Thus, during the US treatment of suspended sedimentary wine yeast a mixture of fatty acid ethyl ester more than 2 times and squalene - 1.5 times, compared to the control, is observed.

In-vitro hypoglycemic activity of lawsonia inermis Linn. Leaf extracts

in-vitro hypoglycemic activity of lawsonia inermis Linn. Leaf extracts

Geochemical mechanisms of natural arsenic mobility in the hydrogeologic system of Lower Katari Basin, Bolivian Altiplano

Arsenic (As) contamination of drinking water is a worldwide problem. The natural origin of As, its mobility, and transport are of paramount interest in Bolivian Altiplano due to its presence in mineral deposits, brines, hot springs, and volcanic rocks. In this study, a geochemical spatial–temporal approach was used to understand the sources and factors that regulate the mobilization and fate of As in water bodies as well as sediments of Lower Katari Basin (LKB). The study reveals that high levels of As (288 µg/L), boron (B) (2473 µg/L), manganese (Mn) (7259 µg/L), and high salinity (23850 µS/cm) are present in shallow drinking water wells, which exceed the guideline values of the Bolivian regulation (NB-512) and WHO. Seasonal changes (mean monthly rainfall in the dry and rainy period: 6–89 mm) and their impact on water quantity (0.9–5.1 m3/s), in addition to the load of solids and liquids of residual origin (Pallina River), pose health risks for the communities at the banks of the Katari River. The hydrogeological study indicates that the groundwater flows from southeast to northwest (SE–NW), which indicate interaction between groundwater and surface water in this region. The spatial distribution of As varies considerably due to geological characteristics of the area as well as due to the heterogeneously distributed evaporites in the sediments (alluvial, fluvial-lacustrine); however, the highest concentrations of As are observed in the alluvial sediments of the northern region. Sequential extraction (BCR) of sediments along with geochemical modeling (mineral saturation indices) indicates that iron (Fe) and aluminum (Al) (hydr)oxides are the most important adsorbent minerals of As in the central and southern region of LKB. The hydrochemistry of water bodies in LKB is strongly influenced by the interaction with the sediment constituents and by the spatial–temporal variations. Therefore, the determination of the distribution of As among the different geochemical fractions was useful to find the relative proportions of As transported by different chemical mechanisms (adsorption/dissolution) and their spatial–temporal variation.

Phosphorus forms in the sediment of seagrass meadows affected mainly by fungi rather than bacteria: a preliminary study based on 31P-NMR and high-throughput sequencing

Abstract Microorganisms play an important role in the circulation of phosphorus (P) in the sediment of coastal wetland ecosystems. In this study, solution 31P nuclear magnetic resonance (NMR) was used to determine different forms of P in the sediments of four different seagrass meadows and a bare tidal flat, while high-throughput 16S and ITS rRNA gene sequencing was used to determine the microbial community composition. The solution 31P-NMR spectra revealed six forms of the P compounds detected by the NaOH-EDTA extraction of sediments, where Ortho-P was the most dominant P compound, followed by Mono-P. The Po compounds were more varied in the seagrass meadow sediments and more abundant compared to the bare tidal flat. Bacterial communities in the sediments collected from E. acoroides and fungal communities in the bare tidal flat were relatively different from those at the other sites. The relative abundance of P-cycling-related fungi belonging to the phylum Ascomycota was 26.20% and was much higher than that of bacteria (only 0.29%) belonging to the class Bacilli. Mono-P was the major factor determining the distribution of P-cycling-related fungi and negatively correlated with the relative abundance of Aspergillus and Trichoderma. We believe that fungi can affect P forms in the sediment of seagrass meadows more than bacteria.

Heart development in two populations of Atlantic killifish (Fundulus heteroclitus) following exposure to a polycyclic aromatic hydrocarbon mixture

Historic industrial pollution of the Elizabeth River, Virginia resulted in polycyclic aromatic hydrocarbon (PAH) contamination in sediments. Atlantic killifish (Fundulus heteroclitus) inhabiting the Atlantic Wood (AW) industrial site adapted to complex PAH mixture at this Superfund site. Their embryos have proved highly resistant to cardiac abnormalities indicative of PAH toxicity. In this study, embryos spawned from adults collected at AW and King’s Creek (KC), a reference site, were exposed at 24 h post fertilization (hpf) to Elizabeth River Sediment Extract (ERSE), a complex PAH mixture, in a range of concentrations (0, 5.04, 50.45, 100.90, 151.35, or 252.25 µg/L total PAHs). Embryos were processed for histology at 144 hpf to enable evaluations of hearts at tissue and cellular levels. Morphometry and severity scoring were used to evaluate the extent of alterations. Unexposed embryos were similar in both populations. ERSE exposure resulted in multiple changes to hearts of KC embryos but not AW. Alterations were particularly evident in KC embryos exposed to concentrations above 1% ERSE (50.45 µg/L), which had thinner ventricular walls and larger pericardial edema. Individuals with moderate pericardial edema maintained arrangement and proximity of heart chambers, but changes were seen in ventricular myocytes. Severe pericardial edema was prevalent in exposed KC embryos and typically resulted in tube heart formation. Ventricles of tube hearts had very thin walls composed of small, basophilic cells and lacked trabeculae. Edematous pericardial fluid contained small amounts of proteinaceous material, as did controls, and was free of cells. This fluid was primarily unstained, suggesting water influx due to increased permeability. The use of histological approaches provided more specific detail for tissue and cellular effects in hearts of embryos exposed to PAHs and enabled understanding of potential links to later life effects of early life exposure.

Geochemistry, origin and accumulation of natural gas hydrates in the Qiongdongnan Basin, South China Sea: Implications from site GMGS5-W08

The recent discovery of natural gas hydrates in the Qiongdongnan Basin (QDNB) during the fifth “China National Gas Hydrate Drilling Expedition” (GMGS5) confirms the great potential of gas hydrate resources within this basin. Based on the comprehensive geochemical investigation of the hydrate-related gas and hydrate-bearing sediments collected from the drilled site GMGS5-W08, this study determines the source and accumulation mechanism of gas hydrates. The hydrate-related gases from the site GMGS5-W08 consist of abundant methane (81.21%–97.69%) and some C2+ hydrocarbon gases (2.31%–18.79%). The stable carbon isotopic compositions of C1–C3 hydrocarbon gas components indicate that the methane has a mixed microbial and thermogenic origin (−59.5‰<δ13C1<−48.8‰), while the C2+ hydrocarbon gases are of thermogenic origin derived from coaly-type source rocks (−27.5‰<δ13C2<−22.4‰, −23.2‰<δ13C3<−20.2‰). The sediment samples collected at site GMGS5-W08 are characterized by low total organic carbon (TOC) contents (mostly < 0.4%), low hydrocarbon indices (mostly < 50 mg HC/g TOC), and low in situ temperatures (3.5°C-21°C), suggesting a poor microbial gas generation potential for the in situ uncompacted sediments. The extracts of the hydrate-bearing sediments are composed of in situ immature terrigenous organic matters and allochthonous mature hydrocarbons from the deeply buried strata. The allochthonous hydrocarbons (C14+ components) approximately originate from the low mature to mature marine mudstones (0.75%<calculated vitrinite reflectance (%Rc)<0.87%) of the Miocene Sanya and Meishan formations. The accumulation process of hydrate gas at site GMGS5-W08 can be subdivided into three stages: migration of gas and liquid hydrocarbons (stage I), gas accumulation, pressure increase, and microbial alteration (stage II), and pressure release, gas chimney and gas hydrate occurrence (stage III). The microbial methane within the gas hydrates is mainly derived from the secondary microbial methane generated in stage II and primary microbial methane generated from sediments within the zone of optimal temperature (35°C–75°C).

Evolution assessment of structurally-controlled differential subsidence using SBAS and PS interferometry in an emblematic case in Central Mexico

ABSTRACT The city of Morelia has been affected by Structurally-Controlled Differential Subsidence (SCDS) since at least 1983, modifying civil structures and infrastructure through the appearance of ground failures and differential ground subsidence. The resulting damage to streets, homes, hydraulic lines, and government facilities has caused economic losses worth millions of dollars. An increase in population has led to the overexploitation of groundwater, which is the main trigger for SCDS, while the subsoil's geology and bedrock configuration are considered conditioning factors of this phenomenon. This paper offers an analysis of the SCDS evolution over the last fourteen years and its relationship with groundwater extraction and thickness of unconsolidated sediments. The former was carried out through SAR Interferometry techniques to detect and monitor land subsidence, using Small Baseline Subset (SBAS) from 2003 to 2010 and Persistent Scatterer Interferometry (PSI) from 2014 to 2017. Additionally, groundwater pumping well data and lithological information from boreholes enabled a spatial analysis to evaluate the role of these factors in the development and acceleration of SCDS. The SBAS results show maximum sinking rates of 2.2 cm/yr. with a spatial distribution that is clearly controlled by buried geological structures. In this period, the maximum sinking rates were induced by high groundwater extraction rates in focused areas, while intermediate rates were linked to notable depletion cones. The PSI results indicate a maximum sinking rate of 2.74 cm/yr. and an accelerated subsidence migration to the west, owing to the construction of new wells and persistent high groundwater extraction rates. For both periods, the larger compressible sediment package reveals a good correlation with high subsidence rates, mainly in the hanging wall blocks of the buried faults. The identification of differential subsidence accompanied by high sinking rates in novel areas of Morelia, as well as the detection of the subsidence migration, will provide scientific support to decision-makers for the proposal of engineering solutions and urban planning capable of reducing hydrogeological hazards associated with SCDS.

Identification of potential toxicants in sediments from an industrialized area in Pohang, South Korea: Application of a cell viability assay of microalgae using flow cytometry

Potential toxicants in sediments collected from an industrialized bay of Korea were identified by use of effect-directed analysis (EDA). Three marine microalgal bioassays (Dunaliella tertiolecta, Isochrysis galbana, and Phaeodactylum tricornutum) with diverse endpoints were employed. Initial screening of raw organic extracts of sediments indicated large variations among locations and species in a traditional endpoint “inhibition of growth”. After fractionation, inhibition of growths increased significantly, particularly in some fractions containing aromatics with log KOW 5−6 (F2.6). While viabilities of cells were adversely affected in more fractions, including F2.6−F2.7 (log KOW 5−7) and F3.5−F3.6 (log KOW 4–6). Among the several endpoints of viability, esterase activity seemed to be more sensitive, followed by integrity of cell membranes, chlorophyll a, cell size, and intracellular complexity. Instrumental analyses indicated that toxicities to microalgae observed in F2.7 could not be fully explained by target PAHs. Full-scan screening analysis using GC-QTOFMS identified 58 compounds in F2.7 with matching scores ≥90%. Based on toxic potencies for these compounds predicted by ECOSAR, several causative agents, including 1-phenylpyrene, dibenz[a,c]anthracene, and picene were suggested. Overall, viability of microalgae provided sensitive and high-resolution toxicity screening of samples into integrative assessment of sediment.

The Single and Combined Effects of Wildfire Runoff and Sediment-Bound Copper on the Freshwater Amphipod Hyalella azteca.

The frequency of wildfire is expected to increase with time as a function of climate change. Recent studies in our laboratory have demonstrated that pyrogenic polycyclic aromatic hydrocarbons can cause greater-than-additive effects in Hyalella azteca in the presence of low concentrations of Cu. We hypothesized that freshwater animals inhabiting Cu-contaminated sites, such as those in the vicinity of Cu mines, may be vulnerable to nonadditive toxicity from contaminants released by wildfires. To investigate the interaction between Cu and water conditioned by burnt wood ash (fire extract), we exposed H. azteca for 14 d to binary mixtures of 225 mg/kg Cu-enriched artificial sediment (225 mg Cu/kg) and a fire extract dilution series (12.5, 25, 50, 75, and 100%). All binary mixtures of Cu-enriched sediment and fire extract resulted in complete mortality with the exception of Cu-enriched sediment + 12.5% fire extract. The combination of Cu-enriched sediment with 12.5% fire extract had a more-than-additive effect on survival and tissue Cu concentration, but there was no reduction in growth or acetylcholinesterase activity compared to the 225 mg/kg Cu-contaminated sediment or fire extract control, respectively. Acetylcholinesterase activity was significantly reduced in amphipods exposed to fire extract, but the presence of Cu did not exacerbate this effect. The results suggest that Cu-contaminated water bodies that receive runoff from wildfires are at risk of enhanced toxicity. Environ Toxicol Chem 2020;39:1988-1997. © 2020 SETAC.

Hydrogeochemical contrasts in the shallow aquifer systems of the Lower Katari Basin and Southern Poopó Basin, Bolivian Altiplano

Drinking water sources in the southeastern part of Lake Titicaca (Lower Katari Basin: LKB) and the southern part of Lake Poopó (Southern Poopó Basin: SPB) have high concentrations of arsenic (As), >10 μg/L compared to the WHO and NB-512 guideline value. These regions belong to the Bolivian Altiplano and are characterized by a semiarid climate, slow hydrological flow, with geological formations of volcanic origin, in addition to brines and other mineral deposits. The present study is focused on comparing the geochemical processes of As in relation to the sources and mobilization in groundwater (GW) in LKB and SPB. Groundwater (GW), surface water (SW) and sediment samples were collected from both basins. The As (LKB: 0.8–288 μg/L and SPB: 2.6–207 μg/L), boron (B) (LKB: 96–2473 μg/L and SPB: 507–4359 μg/L), manganese (Mn) (LKB: 0.6–7259 μg/L) and salinity (LKB: 125–11740 μS/cm) were found to be higher than the WHO guideline values, which is a serious concern about the GW quality for human consumption. The dissolution and exchange of bases are the processes that govern the mineralization of GW. Load of solids and liquids of anthropogenic origin in surface water (LKB) represents an environmental problem for communities on river banks. The spatial distribution of As was attributed to the geology of both the basins and the heterogeneously distributed evaporites in the sediments. The highest As concentrations are found in alluvial sediments of the northern region of LKB and “PACK belt” (an approximately 25 km long belt stretching along the southern shores of the Lake Poopó, between the villages of Pampa Aullagas and Condo K) in SPB. Sequential extraction of sediment and mineral saturation indices indicate that iron (Fe) and aluminum (Al) oxides as well as hydroxides are the most predominant mineral phases as potential sorbents of As.

The success of Gonyostomum semen (Raphidophyceae) in a boreal lake is due to environmental changes rather than a recent invasion

The freshwater microalgal species, Gonyostomum semen, has increased in abundance and distribution in boreal lakes during the past few decades, concerning ecologists and water managers. Due to its rapid spread, G. semen has often been referred to as an invasive species, although it was first described in the 1800s. We hypothesized that G. semen is not an invasive species in Norwegian lakes, and that the increasing success is due to beneficial changes in environmental conditions for this species during the past century. We tested these hypotheses by performing a paleolimnological study of a Norwegian Lake, Skjeklesjøen, with known mass occurrence of G. semen. A specific G. semen pigment biomarker, heteroxanthin, was used to detect this species in layers of a sediment core with known age determinations. Environmental factors in both lake and catchment were further investigated and the relationships with the amounts of G. semen was tested. Our results suggested that G. semen was in fact not an invasive species in this lake the past decades. Several factors were identified as plausible drivers for G. semen in this boreal lake. Between 1874–2016, the increasing levels of G. semen in Lake Skjeklesjøen was most closely correlated with Carbon (C), lake color (measured as absorbance of sediment extracts), Nitrogen (N) and spring temperature. Our results suggest that the rapid increase in G. semen population in this boreal lake over the past 70 years was probably due to a combination of climate change and local anthropogenic activities in the catchment, causing increased browning and increased inputs of organic matter and nutrients.

Participatory Bayesian modelling for sustainable and efficient river restoration projects: Feedback from the case study of the Gave de Pau River, Hautes‐Pyrénées, France

AbstractThrough the diversity of criteria and stakes, the uncertain nature of the entailed phenomena and the multi‐scale aspects to be taken into account, a river restoration project can be considered as a complex problem. Integrative approaches and modelling tools are thus needed to help river managers make predictions on the evolution of hydromorphological, socio‐economic, safety and ecological issues. Such approach can provide valuable information for handling long‐term management plans that consider the interaction and the balance of stakeholders interests and river system functioning. In this paper, we present a probabilistic participatory modelling (PM) method that assesses the effects of given restoration actions, knowing the hydromorphological modifications that they may induce on the safety, ecological and socio‐economic aspects with the help of local stakeholders through several workshops. To support this strategy, we used Bayesian networks (BNs) as modelling tools as their causal graphs can combine multidimensional knowledge and data from diverse natures. We introduce the causal graphs elaborated with the help of the stakeholders and convert it into BNs that can assist restoration decisions by considering the available decision and utility functions to provide guidance to decision‐makers. This was applied to the “Lac des Gaves” reach in the Hautes‐Pyrénées, France, a reach that has gone through severe sediment extractions for over 50 years. Each network represents possible restoration decisions linked to one of the observed issues. The paper demonstrates how BNs used as a decision support system (DSS) can help to assess the influence of given management strategies on the river system with the consideration of stakeholders’ knowledge and integration in all the modelling process.

Aryl-enclosed polyketides from mangrove sediment associated bacterium Bacillus amyloliquefaciens attenuating pro-inflammatory 5-lipoxygenase

Two aryl-enclosed polyketides were identified from the ethyl acetate extract of mangrove sediment associated bacterium Bacillus amyloliquefaciens, and were characterized as 1-(8-hydroxy-1-oxoisochroman-3-yl)propyl 4′-(6′-hydroxy-8′- oxotetrahydrofuran-5′-yl)acetate (compound 1) and 6′a-(3′-(1′-(8-hydroxy-1-oxoisochroman-3-yl)propoxy)-3′-oxoethyl)- 8′-oxotetrahydrofuran-6′-yl butyrate (compound 2) by detailed spectroscopic techniques encompassing two-dimensional nuclear magnetic resonance and mass spectroscopic experiments. Polyketide compound 2 bearing oxotetrahydrofuran-6′-yl butyrate moiety exhibited potential antioxidant activities against the free radicals, 2,2-diphenyl-1-picrylhydrazyl radical and 2,2′-azino-bis-3-ethylbenzothiozoline-6-sulfonic acid (IC50 1.01 and 1.22 mM, respectively), and were found to be significantly greater than those displayed by polyketide 1 and standard (α-tocopherol IC50 1.45–1.63 mM, p < 0.05). Compound 2 also exhibited greater anti-inflammatory properties as determined by 5-LOX inhibitory assay (IC50 1.11 mM) than those displayed by compound 1 (IC50 1.23 mM) and standard (ibuprofen IC50 4.50 mM). Greater electronic parameters of compound 2 could further support its greater bioactive potentials.

Comparison of microplastic isolation and extraction procedures from marine sediments

Microplastics (MPs) are small (<5 mm) plastic particles which pose a threat to marine ecosystems. Identifying MPs is crucial for understanding their fate and effects. Many MP extraction methods exist, but procedural differences prevent meaningful comparisons across datasets. This method comparison examines the efficiency of five methods for extracting MPs (40–710 μm) from marine sediments. Known quantities of MPs were spiked into sediments. The MPs were extracted and enumerated to demonstrate percent recovery. Findings determined that sediment matrix, MP properties, and extraction method affect the percent recovery of MPs from sediments. Average recoveries of spiked microplastics were between 0 and 87.4% and varied greatly by sediment type, microplastic, and method of extraction. In general, larger particle and lower density MPs were more effectively recovered. Marine sediments low in organic matter and with larger grain size also had higher percent recoveries of MPs. These findings support the need for method optimization and unified procedures.