Core Species Research Articles

Temperature-mediated microbial carbon utilization in China's lakes.

Microbes play an important role in aquatic carbon cycling but we have a limited understanding of their functional responses to changes in temperature across large geographic areas. Here, we explored how microbial communities utilized different carbon substrates and the underlying ecological mechanisms along a space-for-time substitution temperature gradient of future climate change. The gradient included 47 lakes from five major lake regions in China spanning a difference of nearly 15°C in mean annual temperatures (MAT). Our results indicated that lakes from warmer regions generally had lower values of variables related to carbon concentrations and greater carbon utilization than those from colder regions. The greater utilization of carbon substrates under higher temperatures could be attributed to changes in bacterial community composition, with a greater abundance of Cyanobacteria and Actinobacteriota and less Proteobacteria in warmer lake regions. We also found that the core species in microbial networks changed with increasing temperature, from Hydrogenophaga and Rhodobacteraceae, which inhibited the utilization of amino acids and carbohydrates, to the CL500-29-marine-group, which promoted the utilization of all almost carbon substrates. Overall, our findings suggest that temperature can mediate aquatic carbon utilization by changing the interactions between bacteria and individual carbon substrates, and the discovery of core species that affect carbon utilization provides insight into potential carbon sequestration within inland water bodies under future climate warming.

Exploring the Relationship between the Gut Mucosal Virome and Colorectal Cancer: Characteristics and Correlations.

The fecal virome has been reported to be associated with CRC. However, little is known about the mucosal virome signature in CRC. This study aimed to determine the viral community within CRC tissues and their contributions to colorectal carcinogenesis. Colonic mucosal biopsies were harvested from patients with CRC (biopsies of both neoplasia and adjacent normal tissue (CRC-A)) and healthy controls (HC). The shot-gun metagenomic sequencing of virus-like particles (VLPs) was performed on the biopsies. Viral community, functional pathways, and their correlations to clinical data were analyzed. Fluorescence in situ hybridizations (FISH) for the localization of viruses in the intestine was performed, as well as quantitative PCR for the detection of Torque teno virus load in human mucosal VLP DNA. A greater number and proportion of core species were found in CRC tissues than in CRC-A and HC tissues. The diversity of the mucosal virome in CRC tissues was significantly increased compared to that in HC and CRC-A tissues. The mucosal virome signature of CRC tissues were significantly different from those of HC and CRC-A tissues at the species level. The abundances of eukaryotic viruses from the Anelloviridae family and its sub-species Torque teno virus (TTV) were significantly higher in CRC patients than in HC. Furthermore, increased levels of TTV in the intestinal lamina propria were found in the CRC group. Multiple viral functions of TTV associated with carcinogenesis were enriched in CRC tissues. We revealed for the first time that the mucosal virobiota signature of CRC is characterized by a higher diversity and more eukaryotic viruses. The enrichment of TTV species in CRC tissues suggests that they may play an oncogenic role in CRC. Targeting eukaryotic viruses in the gut may provide novel strategies for the prevention and treatment of CRC.

A panel study on the effect of atmospheric PM2.5 exposure on the gut microbiome in healthy elderly people aged 60-69 years old

Objective: To analyze the short-term effect of individual atmospheric PM2.5 exposure on the diversity, enterotype, and community structure of gut microbiome in healthy elderly people in Jinan, Shandong province. Methods: The present panel study recruited 76 healthy elderly people aged 60-69 years old in Dianliu Street, Lixia District, Jinan, Shandong Province, and followed them up five times from September 2018 to January 2019. The relevant information was collected by questionnaire, physical examination, precise monitoring of individual PM2.5 exposure, fecal sample collection and gut microbiome 16S rDNA sequencing. The Dirichlet multinomial mixtures (DMM) model was used to analyze the enterotype. Linear mixed effect model and generalized linear mixed effect model were used to analyze the effect of PM2.5 exposure on gut microbiome α diversity indices (Shannon, Simpson, Chao1, and ACE indices), enterotype and abundance of core species. Results: Each of the 76 subjects participated in at least two follow-up visits, resulting in a total of 352 person-visits. The age of 76 subjects was (65.0±2.8) years old with BMI (25.0±2.4) kg/m2. There were 38 males accounting for 50% of the subjects. People with an educational level of primary school or below accounted for 10.5% of the 76 subjects, and those with secondary school and junior college or above accounting for 71.1% and 18.4%. The individual PM2.5 exposure concentration of 76 subjects during the study period was (58.7±53.7) μg/m3. DMM model showed that the subjects could be divided into four enterotypes, which were mainly driven by Bacteroides, Faecalibacterium, Lachnospiraceae, Prevotellaceae, and Ruminococcaceae. Linear mixed effects model showed that different lag periods of PM2.5 exposure were significantly associated with a lower gut α diversity index (FDR<0.05 after correction). Further analysis showed that PM2.5 exposure was significantly associated with changes in the abundances of Firmicutes (Megamonas, Blautia, Streptococcus, etc.) and Bacteroidetes (Alistipes) (FDR<0.05 after correction). Conclusion: Short-term PM2.5 exposure is significantly associated with a decrease in gut microbiome diversity and changes in the abundance of several species of Firmicutes and Bacteroidetes in the elderly. It is necessary to further explore the underlying mechanisms between PM2.5 exposure and the gut microbiome, so as to provide a scientific basis for promoting the intestinal health of the elderly.

Microbial inoculants enhance the persistence of antibiotic resistance genes in aerobic compost of food waste mainly by altering interspecific relationships

The effects of microbial inoculants on ARG removal in composting are poorly understood. Here, a co-composting method for food waste and sawdust amended with different microbial agents (MAs) was designed. The results show that the compost without MA unexpectedly achieved the best ARG removal. The addition of MAs markedly increased the abundance of tet, sul and multidrug resistance genes (p < 0.05). Structural equation modeling demonstrated that MAs can enhance the contribution of the microbial community to ARG changes by reshaping community structure and altering the ecological niche, causing the proliferation of individual ARGs, an effect related to the MA component. Network analysis revealed that inoculants weakened the correlation between ARGs and community but increased the linkage between ARGs and core species, suggesting that inoculant-induced ARG proliferation may correspond with gene exchange occurring mainly between core species. The outcome provides new insights into MA application for ARG removal in waste treatment.

Mechanistic insight into the enhanced NO reduction by CO over a pre-reduced CuxOy-CeO2 multiphase catalyst

The CuxOy(9)-CeO2(1) catalyst contained with the low-valent Cu species was synthesized by a two-step method and employed for NO reduction by CO (NO+CO reaction), which was distinguished from the traditional CuxCe1−xO2 solid solution oxide catalyst because it was a variety of interaction of composite heterogeneous catalyst rather than pure solid solutions or loaded catalysts. The CuxOy(9)-CeO2(1)-pre catalyst after CO pretreatment showed almost 100% NO conversion and also early 100% selectivity to N2 at 150 °C in a reaction atmosphere with a CO to NO concentration ratio of 10, which were markedly superior to CuxOy(9)-CeO2(1)-no pre without CO pretreatment, Cu2O, and CeO2 catalysts. The analysis showed multi-electron cycling systems, including the transformation between Cu+ and Cu0, Cu+ and Cu2+, and the interaction between Cu+/Cu2+ and Ce3+/Ce4+ conducive to improving the REDOX performance of the catalyst. In addition, CO pretreatment was beneficial to producing and stabilizing surface synergistic oxygen vacancies (SSOVs) in the Cu-□-Ce system to promote activity. The in-situ DRIFTS analysis revealed that the NO+CO reaction followed the Mars van Krevelen (MvK) mechanism with Cu+ as the core species. During CO pretreatment, CO would react with the lattice oxygen on the catalyst surface to form the apparent surface oxygen vacancies (SOVs, created on a single metal atom) and SSOVs (mainly on a multi-metal catalyst) for continuous adsorption and reaction. NO could adsorb on oxygen vacancies and dissociate into [N] and [O] atoms, which interacted with CO and eventually generated N2 and CO2, respectively, or filled oxygen vacancies to complete the catalytic cycle. In this process, the formation of SSOVs and the adsorption and dissociation of NO on oxygen vacancies played essential roles.

Diversity Temporal-Spatial Dynamics of Potato Rhizosphere Ciliates and Contribution to Nitrogen- and Carbon-Derived Nutrition in North-East China.

Ciliates are an important component of the rhizosphere microorganism community, but their nutritional contribution to plants has not been fully revealed. In this paper, we investigated the rhizosphere ciliate community of potatoes during six growth stages, illustrated the spatial-temporal dynamics of composition and diversity, and analyzed the correlation between soil physicochemical properties. The contributions of ciliates to the carbon- and nitrogen-derived nutrition of potatoes were calculated. Fifteen species of ciliates were identified, with higher diversity in the top soil, which increased as the potatoes grew, while they were more abundant in the deep soil, and the number decreased as the potatoes grew. The highest number of species of ciliates appeared in July (seedling stage). Among the five core species of ciliates, Colpoda sp. was the dominant species in all six growth stages. Multiple physicochemical properties affected the rhizosphere ciliate community, with ammonium nitrogen (NH4+-N) and the soil water content (SWC) greatly influencing ciliate abundance. The key correlation factors of ciliates diversity were NH4+-N, available phosphorus (AP), and soil organic matter (SOM). The annual average contribution rates of carbon and nitrogen by rhizosphere ciliates to potatoes were 30.57% and 23.31%, respectively, with the highest C/N contribution rates reaching 94.36% and 72.29% in the seedling stage. This study established a method for estimating the contributions of carbon and nitrogen by ciliates to crops and found that ciliates could be potential organic fertilizer organisms. These results might be used to improve water and nitrogen management in potato cultivation and promote ecological agriculture.

Local environment, surface characteristics and stochastic processes shape the dynamics of urban dustbin surface microbiome

Dustbins function as critical infrastructures for urban sanitation, creating a distinct breeding ground for microbial assemblages. However, there is no information regarding the dynamics of microbial communities and the underlying mechanism for community assembly on dustbin surfaces. Here, surface samples were collected from three sampling zones (business building, commercial street and residential community) with different types (kitchen waste, harmful waste, recyclables, and others) and materials (metallic and plastic); and distribution pattern and assembly of microbial communities were investigated by high-throughput sequencing. Bacterial and fungal communities showed the distinct community variations across sampling zones and waste sorting. Core community and biomarker species were significantly correlated with the spatial distribution of overall community. The detection of pathogens highlighted the potential risk of surface microbiome. Human skin, human feces and soil biomes were the potential source environments of the surface microbiomes. Neutral model prediction suggested that microbial community assembly was significantly driven by stochastic processes. Co-association patterns varied with sampling zones and waste types, and neutral amplicon sequence variants (ASVs) that fall within the 95 % confidence intervals of neutral model were largely involved in the stability of microbial networks. These findings improve our understanding of the distribution pattern and the underlying assembly of microbial community on the dustbin surface, thus enabling prospective prediction and assessment of urban microbiomes and their impacts on human health.

The initial composition and structure of microbial community determined the yield and quality of Baijiu during the spontaneous fermentation.

The microbiota during pit mud fermentation is a crucial factor in Baijiu brewing since it determines the yield and flavor. However, the impact of the microbial community during the initial fermentation stage on Baijiu quality remains uncertain. Herein, high-throughput sequencing was employed to investigate the microbial diversities and distribution during Baijiu fermentation in individual pit mud workshops at both initial and late stages. During the initial fermentation stage, the bacterial community exerted a more pronounced effect on Baijiu quality than the fungal community. And the high-yield pit mud workshop exhibited lower richness and evenness, as well as greater Bray-Curtis dissimilarity during Baijiu fermentation. Lactobacillus was the dominant genus and biomarker in high-yield pit mud, and it constituted the only genus within the bacterial association network during the late fermentation stage. Fungal communities tended to maintain a simple association network with selected core species. Based on the correlation network, Rhizopus and Trichosporon were identified as biomarkers in Baijiu fermentation process. Together, Lactobacillus and Rhizopus could serve as bio-indicators for Baijiu quality during the initial fermentation stage. Therefore, these findings provided novel insights into microbiota interactions during fermentation and the impact of initial microbiota on final Baijiu quality.

Parasitic fauna of the Peruvian moonfish Selene peruviana (Perciformes: Carangidae) from the north coast of Peru

Peruvian moonfish Selene peruviana is an abundant resource on the Pacific coasts, with a little-known biology. Regarding its parasitofauna, only two species of parasites have been registered and, given so little information, a parasitological study was carried out on 80 specimens of S. peruviana sampled from the coast of Tumbes, north of Peru, between June and October 2018. The ecological descriptors of parasitic infection/infestation, the degree of parasitic dispersal, the alpha diversity indices and the correlation the parasitological indices and biological characteristics of the fish (TL and sex) were calculated. Two species of monogeneans (Oaxacotyle oaxacensis and Metamicrocotyla macracantha), one species of trematode (Lecithocladium cristatum) and four species of copepods (Naobranchia sp., Lepeophtheirus sp., Caligus sp. and Lernanthropus sp.) were recorded. The monogenean O. oaxacensis was considered the only core species (e.g., with prevalence &gt;45%). The distribution found for O. oaxacensis and L. cristatum was aggregated and there was no association between TL and sex with the parasitological indices. In the case of alpha diversity indices, the Margalef (Dmg), Shannon-Weaver (H´) and Pielou (J´) diversity index values were higher in females, but the Simpson dominance (D) did not show differences between the sexes. The diversity index of parasitic H' showed a higher value in the sizes over sexual maturity of S. peruviana. The parasitic D index presented an opposite pattern. All the parasite species found in this study are new records for S. peruviana and for Peru.

The effect of chemical modification of the surface of the glued surface on the strength of the structural joint of oak wood

Abstract As a result of climate change, the species structure of forest stands is gradually changing when the growing share of core species of deciduous trees at the expense of conifers places demands on its future efficient processing into final products. This study evaluates the influence of the surface modification of the heartwood of oak (Quercus robur) with five selected chemical modifiers on the strength of the glued joint with the used one-component PUR adhesive for interior and exterior structural applications. Samples of test bodies produced according to the standards were exposed to the given environment and subsequently subjected to a test using the method of determining the longitudinal shear strength under tensile stress. By applying a chemical modification to the surface layers of the glued surfaces of oak wood, the tannins in the surface layers were neutralized, increasing the adhesion of the glued surface. The resulting values of the strength of the glued joints with the applied chemical modification of the heartwood surface also confirmed this.

Monoclonal antibody Y01 prevents tauopathy progression induced by lysine 280-acetylated tau in cell and mouse models.

The spatiotemporal pattern of the spread of pathologically modified tau through brain regions in Alzheimer's disease (AD) can be explained by prion-like cell-to-cell seeding and propagation of misfolded tau aggregates. Hence, to develop targeted therapeutic antibodies, it is important to identify the seeding- and propagation-competent tau species. The hexapeptide 275VQIINK280 of tau is a critical region for tau aggregation, and K280 is acetylated in various tauopathies, including AD. However, the mechanism that links tau acetylated on lysine 280 (tau-acK280) to subsequent progression to neurodegenerative disease remains unclear. Here, we demonstrate that tau-acK280 is critical for tau propagation processes including secretion, aggregation, and seeding. We developed an antibody, Y01, that specifically targets tau-acK280 and solved the crystal structure of Y01 in complex with an acK280 peptide. The structure confirmed that Y01 directly recognizes acK280 and the surrounding residues. Strikingly, upon interaction with acetylated tau aggregates, Y01 prevented tauopathy progression and increased neuronal viability in neuron cultures and in tau-Tg mice through antibody-mediated neutralization and phagocytosis, respectively. Based on our observations that tau-acK280 is a core species involved in seeding and propagation activities, the Y01 antibody that specifically recognizes acK280 represents a promising therapeutic candidate for AD and other neurodegenerative diseases associated with tauopathy.

Design and validation of Dolosigranulum pigrum specific PCR primers using the bacterial core genome

Dolosigranulum pigrum—a lactic acid bacterium that is increasingly recognized as an important member of the nasal microbiome. Currently, there are limited rapid and low-cost options for confirming D. pigrum isolates and detecting D. pigrum in clinical specimens. Here we describe the design and validation of a novel PCR assay targeting D. pigrum that is both sensitive and specific. We designed a PCR assay targeting murJ, a single-copy core species gene identified through the analysis of 21 D. pigrum whole genome sequences. The assay achieved 100% sensitivity and 100% specificity against D. pigrum and diverse bacterial isolates and an overall 91.1% sensitivity and 100% specificity using nasal swabs, detecting D. pigrum at a threshold of 1.0 × 104D. pigrum 16S rRNA gene copies per swab. This assay adds a reliable and rapid D. pigrum detection tool to the microbiome researcher toolkit investigating the role of generalist and specialist bacteria in the nasal environment.

Diversity and Assembly of Bacteria Community in Lime Soil under Different Karst Land-Use Types

Bacteria play an important role as decomposers in karst ecosystems, which can be associated with karst soil and plants, promoting the cycling of nutrients between plants and soil. To reveal the diversity and structure of soil bacterial communities in some karst land-use types after the Grain for Green pattern, soil samples were collected from different land-use types (crops, grasses, and plantations) for analysis. Changes in the structure and assembly of karst soil bacteria were examined using 16S rRNA Illumina sequencing and soil chemical properties. We found that 18 years after the Grain for Green program, the soil chemical properties of available nitrogen (AN), total phosphorus (TP), total nitrogen (TN), and soil organic matter (SOM) of grassland were significantly different from those of farmland. The soil chemical properties in plantations were also significantly lower than those in farmlands. Different land-use types did not significantly affect the soil bacterial community structure. Actinobacteria, Proteobacteria, Chloroflexi, and Acidobacteria were the dominant phyla in all the plots. The relative abundance of Proteobacteria was higher in grasslands and plantations than in farmlands, whereas that of Actinobacteria was lower in grasslands. Furthermore, no significant correlations were observed between the soil chemical factors and soil bacterial groups at the genus level. The null model analysis indicated that dispersal limitations in stochastic processes predominated for the different land-use systems. Combined with previous analyses of the factors driving bacterial core species diversity in karst soils, we speculated that stochastic processes play a more important role in the construction of core bacterial species in restored karst soils at the plot scale.

Core species and interactions prominent in fish-associated microbiome dynamics

BackgroundIn aquatic ecosystems, the health and performance of fish depend greatly on the dynamics of microbial community structure in the background environment. Nonetheless, finding microbes with profound impacts on fish’s performance out of thousands of candidate species remains a major challenge.MethodsWe examined whether time-series analyses of microbial population dynamics could illuminate core components and structure of fish-associated microbiomes in the background (environmental) water. By targeting eel-aquaculture-tank microbiomes as model systems, we reconstructed the population dynamics of the 9605 bacterial and 303 archaeal species/strains across 128 days.ResultsDue to the remarkable increase/decrease of constituent microbial population densities, the taxonomic compositions of the microbiome changed drastically through time. We then found that some specific microbial taxa showed a positive relationship with eels’ activity levels even after excluding confounding effects of environmental parameters (pH and dissolved oxygen level) on population dynamics. In particular, a vitamin-B12-producing bacteria, Cetobacterium somerae, consistently showed strong positive associations with eels’ activity levels across the replicate time series of the five aquaculture tanks analyzed. Network theoretical and metabolic modeling analyses further suggested that the highlighted bacterium and some other closely-associated bacteria formed “core microbiomes” with potentially positive impacts on eels.ConclusionsOverall, these results suggest that the integration of microbiology, ecological theory, and network science allows us to explore core species and interactions embedded within complex dynamics of fish-associated microbiomes. 2gKjfWoBRNSUwrepeh_GG8Video

Change in Cerebrospinal Fluid Tau Microtubule Binding Region Detects Symptom Onset, Cognitive Decline, Tangles, and Atrophy in Dominantly Inherited Alzheimer's Disease.

Identifying cerebrospinal fluid measures of the microtubule binding region of tau (MTBR-tau) species that reflect tau aggregation could provide fluid biomarkers that track Alzheimer's disease related neurofibrillary tau pathological changes. We examined the cerebrospinal fluid (CSF) MTBR-tau species in dominantly inherited Alzheimer's disease (DIAD) mutation carriers to assess the association with Alzheimer's disease (AD) biomarkers and clinical symptoms. Cross-sectional and longitudinal CSF from 229 DIAD mutation carriers and 130 mutation non-carriers had sequential characterization of N-terminal/mid-domain phosphorylated tau (p-tau) followed by MTBR-tau species and tau positron emission tomography (tau PET), other soluble tau and amyloid biomarkers, comprehensive clinical and cognitive assessments, and brain magnetic resonance imaging of atrophy. CSF MTBR-tau species located within the putative "border" region and one species corresponding to the "core" region of aggregates in neurofibrillary tangles (NFTs) increased during the presymptomatic stage and decreased during the symptomatic stage. The "border" MTBR-tau species were associated with amyloid pathology and CSF p-tau; whereas the "core" MTBR-tau species were associated stronger with tau PET and CSF measures of neurodegeneration. The ratio of the border to the core species provided a continuous measure of increasing amounts that tracked clinical progression and NFTs. Changes in CSF soluble MTBR-tau species preceded the onset of dementia, tau tangle increase, and atrophy in DIAD. The ratio of 4R-specific MTBR-tau (border) to the NFT (core) MTBR-tau species corresponds to the pathology of NFTs in DIAD and change with disease progression. The dynamics between different MTBR-tau species in the CSF may serve as a marker of tau-related disease progression and target engagement of anti-tau therapeutics. ANN NEUROL 2023;93:1158-1172.

Core Species Derived from Multispecies Interactions Facilitate the Immobilization of Cadmium

Microbial consortia have opened new avenues for heavy-metal remediation. However, the limited understanding of the overall effect of interspecific interactions on remediation efficacy hinders its application. Here, the effects of multispecies growth and biofilm formation on Cd immobilization were explored from direct and multiple interactions through random combinations of two or three rhizosphere bacteria. In monocultures, Cd stress resulted in an average decrease in planktonic biomass of 26%, but through cooperation, the decrease was attenuated in dual (21%) and triple cultures (13%), possibly involving an increase in surface polysaccharides. More than 65% of the co-cultures exhibited induction of biofilm formation under Cd stress, which further enhanced the role of biofilms in Cd immobilization. Notably, excellent biofilm-forming ability or extensive social induction makes Pseudomonas putida and Brevundimonas diminuta stand out in multispecies biofilm formation and Cd immobilization. These two core species significantly increase the colonization of soil microorganisms on rice roots compared to the control, resulting in a 40% decrease in Cd uptake by rice. Our study enhances the understanding of bacterial interactions under Cd stress and provides a novel strategy for adjusting beneficial soil consortia for heavy-metal remediation.

In-situ preparation of yeast-supported Fe0@Fe2O3 as peroxymonosulfate activator for enhanced degradation of tetracycline hydrochloride

Nano zero-valent iron (nZVI) is extensively used as a peroxymonosulfate (PMS) activator but suffers from the ease of oxidation and agglomeration due to its high surface energy and inherent magnetism. Here, green and sustainable yeast was selected as a support material to firstly in-situ prepare yeast-supported Fe0@Fe2O3 and used for activating PMS to degrade tetracycline hydrochloride (TCH), one of the common antibiotics. Due to the anti-oxidation ability of the Fe2O3 shell and the support effect of yeast, the prepared Fe0@Fe2O3/YC exhibited a superior catalytic activity for the removal of TCH as well as some other typical refractory contaminants. The chemical quenching experiments and EPR results demonstrated SO4•− was the main reactive oxygen species while O2•−, 1O2 and •OH played a minor role. Importantly, the crucial role of the Fe2+/Fe3+ cycle promoted by the Fe0 core and surface iron hydroxyl species in PMS activation was elucidated in detail. The TCH degradation pathways were proposed by LC-MS and density functional theory (DFT) calculation. In addition, the outstanding magnetic separation property, anti-oxidation ability, and high environmental resistance of the catalyst were demonstrated. Our work may inspire the development of green, efficient, and robust nZVI-based materials for wastewater treatment.

Occurrence of OCPs & PCBs and their effects on multitrophic biological communities in riparian groundwater of the Beiluo River, China

Persistent Organic Pollutants (POPs) may exert adverse effects on human and ecosystem health. However, as an ecologically fragile zone with strong interaction between river and groundwater, the POPs pollution in the riparian zone has received little attention. The goal of this research is to examine the concentrations, spatial distribution, potential ecological risks, and biological effects of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in the riparian groundwater of the Beiluo River, China. The results showed that the pollution level and ecological risk of OCPs in riparian groundwater of the Beiluo River were higher than PCBs. The presence of PCBs (Penta-CBs, Hexa-CBs) and CHLs, respectively, may have reduced the richness of bacteria (Firmicutes) and fungi (Ascomycota). Furthermore, the richness and Shannon’s diversity index of algae (Chrysophyceae and Bacillariophyta) decreased, which could be linked to the presence of OCPs (DDTs, CHLs, DRINs), and PCBs (Penta-CBs, Hepta-CBs), while for metazoans (Arthropoda) the tendency was reversed, presumably as a result of SULPHs pollution. In the network analysis, core species belonging to bacteria (Proteobacteria), fungi (Ascomycota), and algae (Bacillariophyta) played essential roles in maintaining community function. Burkholderiaceae and Bradyrhizobium can be considered biological indicators of PCBs pollution in the Beiluo River. Note that the core species of interaction network, playing a fundamental role in community interactions, are strongly affected by POPs pollutants. This work provides insights into the functions of multitrophic biological communities in maintaining the stability of riparian ecosystems through the response of core species to riparian groundwater POPs contamination.

Post-sulfidation of biochar supported nanoscale zero-valent iron with different sulfur precursors: Reactivity and selectivity on tetrabromobisphenol A reduction

Herein, post-sulfidation method is applied for the first time to synthesize biochar supported sulfidated nanoscale zero valent iron (S-nZVI/BC), and the impact of sulfur (S) precursors (Na2S, Na2S2O3, and Na2S2O4) on the physicochemical properties, reactivity, selectivity, pH resistance, and long-term performance of S-nZVI/BC was investigated for tetrabromobisphenol A (TBBPA) degradation. Detailed characterizations indicated that S-nZVI/BC with different S precursors altered distribution/content of S species (i.e., S2−, Sn2−, and SO42−) in shell and core (>10 nm). The BC largely contributed to increase the sulfidation efficiency and dispersion of S-nZVI. The reactivity of S2−-nZVI/BC was ∼ 9.6 and ∼ 3.0–6.7 times higher than that of nZVI/BC and other S-nZVI/BCs, respectively, deriving from the higher Fe0 crystallinity, more hydrophobicity and proportion of reduced S species. Remarkably, the adverse effect of surface oxidized S species (i.e., SO42−) was more significant than the promoting effect induced by the surface reduced S species (i.e., S2− and Sn2−) on reactivity when there were excessive SO42− species. The selectivity of S2O42−-nZVI/BC was ∼ 203 and ∼ 1.5–3.5 times higher than that of nZVI/BC and other S-nZVI/BCs at same dosed S/Fe molar ratio (0.3), respectively, which was well correlated with the [S/Fe]particle molar ratio. Besides, increased electron efficiency with pH rise was because the passivation of surface FexOy layer (hydrogen evolution reaction sites) enabled electrons more selectively transported to FeSx surface (debromination sites). S2−-nZVI/BC remained more reactive after aging in water over 30 d than nZVI/BC and other S-nZVI/BCs. This work suggested that S precursors had crucial effects on the property and performance of S-nZVI/BC, which can be designed for specific application scenarios.

Bridging the Gap Between Conservation Paleobiology and Resource Management: Recognizing the Past is the Key to the Future

A persistent challenge for conservation paleobiologists is communication of information on past environmental changes to resource managers in a way that allows them to apply these data to current restoration efforts. USGS scientists have learned a few lessons over 25 years of conducting applied paleoecology research in collaboration with the Greater Everglades Ecosystem Restoration (GEER) project. The first step is to engage resource managers in conversations prior to beginning research. What are their goals and information needs? Participation in GEER with teams of scientists and decision-makers working together to develop measures of success for Everglades restoration allowed us to overcome this first hurdle. Our initial research showed changes in salinity and freshwater influx over time, but how to use this information was not immediately apparent to management, so continued communication was critical. Through participation in meetings and presentation of our preliminary findings, the management team provided feedback that led us to develop a modern analog-based method to estimate past salinity, which was then used to adjust system-wide hydrologic models to reflect past conditions. Recently, we realized another management information gap — a set of indicator species for nearshore estuarine zones to monitor the effectiveness of upstream changes in flow. Again, by working with managers to determine needs, we combined distribution data of mollusk species in nearshore cores with our modern analog dataset to develop a suite of indicator species. These are a few examples of positive impacts from our long-term collaboration. We believe the key to advancing the use of conservation paleobiologic research in resource management is to communicate frequently and often, listen closely to management, discuss how paleo data can be applied, and be persistent. It is essential that we bridge these gaps because the past is our window to anticipating and planning for future change.