Mature Communities Research Articles

Diversity and structure of epibenthic communities across subtidal artificial hard habitats in the Bay of Cherbourg (English Channel)

To inform the performance of ecological engineering designs for artificial structures at sea, it is essential to characterise their impacts on the epibenthic communities colonising them. In this context, the present study aims to compare the community structure among natural and four different artificial hard habitats with different ages and features installed in the Bay of Cherbourg (English Channel): i) cinder blocks and ii) boulders, both installed six years prior to the study, and iii) smooth and iv) rugous concrete dykes, both installed one year prior to this study. Results showed that artificial habitats installed six years ago harboured communities with functional and taxonomic diversity characteristic of mature communities but were still different from those of natural habitat. Conversely, the two dyke habitats installed one year prior to this study presented a poorly diversified community dominated by opportunistic taxa. Furthermore, while the concrete used for the two dyke habitats presented different rugosity properties, both habitats supported similar communities, suggesting that such eco-engineering measures did not affect the settlement of early colonisers. Overall, this study highlights the need for long-term monitoring to comprehensively evaluate epibenthic colonisation of artificial structures.

Identification of potential biological corridors for the bobcat (Lynx rufus) in a multipurpose area of northeastern Mexico

The objectives of the research were i) to determine patches and points of origin forthe establishment and connectivity of biological corridors, ii) to estimate the costarea for the establishment of biological corridors, iii) to define biological corridorswith viability for the dispersal of the bobcat (Lynx rufus) in a multipurpose area inReynosa, Tamaulipas. To monitor behavioral patterns, capture and recapturerecords were generated using the photographic sampling method. To calculatedensity, the results were entered into the statistical program CAPTURE. To modelthe potential habitat, the maximum entropy method (MaxEnt) was used. The costsurfaces were obtained with the maps in MaxEnt. The results showed that: i) thereare six patches and points of origin for the establishment and connectivity ofbiological corridors, which presented a mature community of Tamaulipanthornscrub, ii) most of the study area presents values ranging from medium to highon the cost scale, which is correlated with intense landscape modification, and iii)11 potential biological corridors were defined for the dispersal of the bobcat (Lynxrufus) in a multipurpose area in Reynosa, Tamaulipas.

Beyond biomass: Resource effects on primary production and consumer nutrient assimilation in streams

Abstract Primary production in aquatic ecosystems is strongly controlled by resource availability (bottom‐up). At the same time, grazers exert top‐down pressure on algae. The effects of both resources and grazers on algal communities have been investigated extensively for both benthic and planktonic systems. However, most studies focus exclusively on net effects on algal standing stock, while the underlying ecological functions and processes often remain unknown. Here, we tested the effects of the two resources, light (L) and the limiting nutrient phosphorus (P), on both primary production (net oxygen production) by benthic algae (periphyton) and matter assimilation by the next trophic guild (particularly nitrogen assimilation by grazers). For this, we grew natural periphyton communities in stream mesocosm flumes together with two native grazer taxa and 15N as a tracer. Both resources resulted in an initial increase in net primary production, but this effect equalised after 36 days in the more mature communities. While both resources still showed strong positive effects on algal biovolume, the biovolume‐specific net primary production decreased with resource level and was lowest in the double elevated (+L, +P) treatment. The response of nitrogen assimilation by grazers was more closely related to the response of periphyton quality (stoichiometric and taxonomic composition) than to its biomass. In addition, light affected the nitrogen assimilation of both grazers negatively. These findings demonstrate that the responses of ecological functions, here primary production and assimilation by grazers, are not necessarily proportional to algal biomass and are thus not easily predictable from the common use of biomass as a proxy for functions.

192 Effects of inclusion of a probiotic and/or a postbiotic in diets containing a phytogenic feed additive on growth performance and fecal microbiome composition and function of nursery pigs

Abstract This study investigated the effects of inclusion of a Bacillus-based probiotic and a postbiotic from Lactobacillus acidophilus fermentation (Dia-V Nursery, Diamond V, IA) in diets containing a phytogenic feed additive (Fresta Protect, Delacon, Austria) on growth performance and fecal microbiome of pigs. Weaned pigs [n = 1,840; 19 d old; initial body weight (BW) = 6.1 ± 0.2 kg] were allotted to 16 replicate pens/ treatment (23 pigs/pen) in 2 barns. Pens were blocked by location within barn and randomly allotted to 5 treatments: 1) Basal diet (NC), 2) NC without specialty fats (soy oil blend and medium chain fatty acid blend) + 0.1% phytogenic (PC), 3) PC + 0.05% probiotic (1.1 x 106 CFU/kg of complete feed; PC+Prob), 4) PC + 0.2% postbiotic (PC+Post), and 5) PC + 0.05% probiotic + 0.2% postbiotic (PC+Prob+Post). Pigs were fed experimental diets during phase 1 (d 0-10) and 2 (d 10-23). Pig and feed weights were recorded at the beginning and end of each phase. Fecal samples were collected from 2 pigs/pen (n = 32/treatment) on d 7 and 25 post-wean and subjected to DNA extraction and shotgun metagenomics to evaluate gut microbiome. Performance data were analyzed using the lme4 package of R with treatment as fixed effect and barn and pen location within barn as random effects. Microbiome data were center-log-ratio transformed and analyzed for alpha- and beta-diversity, differentially abundant taxa and genes, microbial network, and carbohydrate active enzymes (CAZy). No differences on performance, mortality or removals were observed during phase 1, phase 2, or overall among treatments (Table 1). Microbiome features were similar between NC and PC. The PC+Prob did not affect alpha- and beta-diversities of microbiome. The PC+Post reduced (P < 0.05) alpha-diversity on d 7 compared with PC and affected (P < 0.05) beta-diversity on both timepoints. The PC+Post had the greatest number of differentially abundant taxa (P < 0.05) compared with PC both on d 7 (27 taxa) and 25 (14 taxa). The PC+Post had greater (P < 0.05) presence of CAZy including glycoside hydrolases, glycosyltransferases and carbohydrate-binding modules on both timepoints. Inclusion of probiotic and postbiotic separately or in combination reduced (P < 0.05) the number of positive connections within the microbial network suggesting these additives promoted a more competitive microbial ecosystem against opportunistic microorganisms compared with PC. Inclusion of postbiotic speeded up the progression of microbiome toward a more mature community. This resulted in reduction of diversity but increased carbohydrate enzyme capability making microbial community leaner and more effective. In conclusion, replacement of specialty fats with a phytogenic did not affect piglet performance or microbiome under non-challenge conditions and no differences in performance were observed between PC pigs and those supplemented with a probiotic or postbiotic despite the effects observed in microbiome.

Fecal microbiota colonization dynamics in dairy heifers associated with early-life rumen microbiota modulation and gut health.

Early-life modulation of rumen microbiota holds promise for enhancing calf growth, health, and long-term production in ruminants. However, limited attention has been given to the impact of rumen microbiota modulation on the establishment of hindgut microbiota. In this study, fecal microbiota development was examined in identical twin calves for 12 months. The treatment group (T-group) received adult cow fresh rumen liquid inoculum during the pre-weaning period, while the control group did not (C-group). The effects of inoculum were assessed on calf gut health and as microbial seeding route into the hindgut. The early rumen modulation had no effect on age-related fecal microbiota development. The fecal bacterial community evolved gradually following dietary changes and categorized into pre-weaning and post-weaning communities. Bacterial richness increased with age and stabilized at month 9, while between-sample variation reduced in post-weaning samples. Archaeal load in fecal samples increased after month 4, while archaeal richness increased and stabilized in both groups by month 9. Between-sample similarity was higher during the pre-weaning period, with increased dissimilarity from month 4 onward. Anaerobic fungi were detected in feces at month 4, with richness peaking at month 7. Before month 6, fungal community composition distinctly differed from mature communities. When colostrum, calf rumen, and donor inoculum were evaluated as seeding sources for hindgut colonization, the calf's own rumen was identified as the primary seeding source for fecal bacteria and fungi. Colostrum was a source for several bacteria detected in feces, but these were of temporary importance until weaning. The donor inoculum had limited impact on gut health as diarrhea rates were similar between the T-group and C-group. In conclusion, early-life microbiota modulation shows potential in ruminant development. However, a more targeted approach with bacteria adapted to the hindgut environment may be necessary to modulate hindgut effectively. This research contributes to our understanding of the complex relationship between gut microbiota and calf health and growth.

Annual recurrence of prokaryotic climax communities in shallow waters of the North Mediterranean.

In temperate coastal environments, wide fluctuations of biotic and abiotic factors drive microbiome dynamics. To link recurrent ecological patterns with planktonic microbial communities, we analysed a monthly-sampled 3-year time series of 16S rRNA amplicon sequencing data, alongside environmental variables, collected at two stations in the northern Adriatic Sea. Time series multivariate analyses allowed us to identify three stable, mature communities (climaxes), whose recurrence was mainly driven by changes in photoperiod and temperature. Mixotrophs (e.g., Ca. Nitrosopumilus, SUP05 clade, and Marine Group II) thrived under oligotrophic, low-light conditions, whereas copiotrophs (e.g., NS4 and NS5 clades) bloomed at higher temperatures and substrate availability. The early spring climax was characterised by a more diverse set of amplicon sequence variants, including copiotrophs associated with phytoplankton-derived organic matter degradation, and photo-auto/heterotrophic organisms (e.g., Synechococcus sp., Roseobacter clade), whose rhythmicity was linked to photoperiod lengthening. Through the identification of recurrent climax assemblages, we begin to delineate a typology of ecosystem based on microbiome composition and functionality, allowing for the intercomparison of microbial assemblages among different biomes, a still underachieved goal in the omics era.

CONCEPTUALIZATION OF SUSTAINABILITY OF TERRITORIAL COMMUNITIES (USING THE DECOMPOSITION MODEL)

The purpose of the article is to develop a conceptual approach and justify the key principles of sustainability of territorial communities through the prism of the decomposition model. The achievement of the set goal was facilitated by the use of methods: system analysis - to build contextual and decomposition diagrams of the functional model of a sustainable territorial community; abstract-logical – for describing the sequence of processes in the functional model of the IDEF0 diagram and formulating conclusions regarding the key principles of community sustainability. The article highlights the problems of territorial communities, which have the most significant influence in achieving the Sustainable Development Goals (SDGs). The presence of methodological contradictions regarding the implementation of the concept of sustainable development in the conditions of territorial communities is argued. The necessity of conceptualizing the key principles of sustainability of territorial communities has been determined. The contextual decomposition diagram of the sustainable territorial community model was built and functionally deepened. It has been proven that a mature community is a community that is constantly in search of balance between different spheres of life to meet the needs of the population and achieve harmonious development between economic, social and ecological components, which contributes to the implementation of the Central Development Goals and allows achieving the expected results.

The mature phyllosphere microbiome of grapevine is associated with resistance against Plasmopara viticola.

Phyllosphere microbiota represents a substantial but hardly explored reservoir for disease resistance mechanisms. The goal of our study was to understand the link between grapevine cultivars susceptibility to Plasmopara viticola, one of the most devastating leaf pathogens in viticulture, and the phyllosphere microbiota. Therefore, we analyzed a 16S rRNA gene library for the dominant phyllosphere bacterial phyla Alphaproteobacteria of seven Vitis genotypes at different developmental stages, i.e., flowering and harvesting, via amplicon sequencing. Young leaves had significantly higher Alphaproteobacterial richness and diversity without significant host-specificity. In contrast, the microbial communities of mature leaves were structurally distinct in accordance with P. viticola resistance levels. This statistically significant link between mature bacterial phyllosphere communities and resistant phenotypes was corroborated by beta diversity metrics and network analysis. Beyond direct host-driven effects via the provision of microhabitats, we found evidence that plants recruit for specific bacterial taxa that were likely playing a fundamental role in mediating microbe-microbe interactions and structuring clusters within mature communities. Our results on grape-microbiota interaction provide insights for targeted biocontrol and breeding strategies.

The Succession of the Cellulolytic Microbial Community from the Soil during Oat Straw Decomposition.

The process of straw decomposition is dynamic and is accompanied by the succession of the microbial decomposing community, which is driven by poorly understood interactions between microorganisms. Soil is a complex ecological niche, and the soil microbiome can serve as a source of potentially active cellulolytic microorganisms. Here, we performed an experiment on the de novo colonization of oat straw by the soil microbial community by placing nylon bags with sterilized oat straw in the pots filled with chernozem soil and incubating them for 6 months. The aim was to investigate the changes in decomposer microbiota during this process using conventional sequencing techniques. The bacterial succession during straw decomposition occurred in three phases: the early phase (first month) was characterized by high microbial activity and low diversity, the middle phase (second to third month) was characterized by low activity and low diversity, and the late phase (fourth to sixth months) was characterized by low activity and high diversity. Analysis of amplicon sequencing data revealed three groups of co-changing phylotypes corresponding to these phases. The early active phase was abundant in the cellulolytic members from Pseudomonadota, Bacteroidota, Bacillota, and Actinobacteriota for bacteria and Ascomycota for fungi, and most of the primary phylotypes were gone by the end of the phase. The second intermediate phase was marked by the set of phylotypes from the same phyla persisting in the community. In the mature community of the late phase, apart from the core phylotypes, non-cellulolytic members from Bdellovibrionota, Myxococcota, Chloroflexota, and Thermoproteota appeared. Full metagenome sequencing of the microbial community from the end of the middle phase confirmed that major bacterial and fungal members of this consortium had genes of glycoside hydrolases (GH) connected to cellulose and chitin degradation. The real-time analysis of the selection of these genes showed that their representation varied between phases, and this occurred under the influence of the host, and not the GH family factor. Our findings demonstrate that soil microbial community may act as an efficient source of cellulolytic microorganisms and that colonization of the cellulolytic substrate occurs in several phases, each characterized by its own taxonomic and functional profile.

Using standardized fish‐specific autonomous reef monitoring structures (FARMS) to quantify cryptobenthic fish communities

Abstract Biodiversity inventories and monitoring techniques for marine fishes often overlook small (<5 cm), bottom‐associated (‘cryptobenthic’) fishes, and few standardized, comparative assessments of cryptobenthic fish communities exist. We sought to develop a standardized, quantitative survey method for cryptobenthic fishes that permits their sampling across a variety of habitats and conditions. Fish‐specific autonomous reef monitoring structures (FARMS) are designed to sample cryptobenthic fishes using a suite of accessible and affordable materials. To generate a variety of microhabitats, FARMS consist of three layers of stacked PVC pipes in three different sizes, as well as a bottom and top level of loose PVC‐pipe fragments in a mesh basket. We deployed FARMS across a variety of habitats, including coral reefs, seagrass beds, oyster reefs, mangroves, and soft‐bottom habitats across six locations (Hawai'i, Texas, Panama, Saudi Arabia, Brazil, and Curaçao). From shallow estuaries to coral reefs beyond 100 m depth, FARMS attracted distinct communities of native cryptobenthic fishes with strong site or habitat specificity. Comparing the FARMS to communities sampled with alternative methods (enclosed clove‐oil stations on coral reefs in Panama and oyster sampling units on oyster reefs in Texas) suggests that FARMS yield a subset of cryptobenthic fish species that are representative of those present on local coral and oyster reefs. While FARMS yield fewer individuals per sample, they are efficient sampling devices relative to the sampled area. We demonstrate that FARMS represent a useful tool for standardized collections of cryptobenthic fishes. While natural substrata are bound to yield more mature communities with a larger number of individuals and wider range of specialist species, the potential to deploy and retrieve FARMS in turbid environments, beyond regular SCUBA depth, and where fish collections using anaesthetics or ichthyocides are forbidden suggests that they are a valuable complementary technique to survey fishes in aquatic ecosystems. Deploying FARMS in locations and habitats where cryptobenthic fish communities have not been studied in detail may yield many valuable specimens of unknown or poorly known species.

Composition and variability of core phyllosphere fungal mycobiota on field-grown broccoli

BackgroundFresh vegetables harbor an assemblage of different microorganisms on their surfaces. The phyllosphere microbiota is important for maintaining plant health and managing crop quality before and after harvest. However, the diversity and ecology of fungal communities are largely unexplored in fresh vegetables. This study investigated the phyllosphere mycobiota of field-grown broccoli florets (n = 66) collected from 22 farms across four regions in Korea, using culturing, amplicon sequencing of the internal transcribed spacer region, and microbial network analysis.ResultsMicrobial network analysis identified core genera (Purpureocillium, Filobasidium, Cystofilobasidium, Papiliotrema, Aureobasidium, and unclassified genera of Capnodiales) specific to the broccoli phyllosphere. The composition and network complexity of core and unique populations varied among farming regions, and was associated with local agro-meteorological conditions. The complexity of microbial associations was higher in mature communities than in immature communities, but complexity was lost upon development of plant pathogenic disease. Broccoli mycobiota were classified according to the dominance of Purpurecillium. While Purpurecillium-type microbiota were prevalent in normal samples, Filobasidium-type microbiota were frequently observed in immature, damaged, or postharvest samples.ConclusionsTogether, fungal communities were important components of phyllosphere microbiota on fresh vegetables, and have substantial potential for exploitation to enhance and stabilize plant health and growth.

Water bioproductivity estimate of the equatorial Atlantic under the influence hydrological, hydrochemical and hydrooptical factors in winter 2022

Based on contact observation data obtained in the 60th cruise of the RV “Akademik Ioffe”, water bioproductivity was estimated based on the distribution of chlorophyll a (CCl) and microplankton adenosine triphosphate (CATP) concentrations under changing environmental conditions. These parameters were studied in the western equatorial Atlantic (Vema Fracture Zone, 11°N; Guiana Basin–Guiana section, 4°N–7°N) in the winter of 2022. For the first time, the stages of production–destruction succession were estimated based on the heterotrophic–photoautotrophic index (HPI), and water trophicity was investigated according to ATP content in the study area. According to the data obtained on CCl, CATP, and HPI, in the Vema Fracture Zone, waters were mesotrophic, with prevalence of communities of mixed nutrition — heterotrophs and autotrophs (an equilibrium community; HPI 15–25). In the Guiana section area, waters were oligotrophic, with prevalence of heterotrophic nutrition (developed and mature communities; HPI: 25–112 and 112–163). At the first bioproductivity depth maximum (10 m), significant relationships were obtained between spatial distribution of concentrations of chlorophyll a and phosphates (r > 0.5) and oxygen (r > 0.68), as well as between microplankton ATP and phosphates and pH (r > 0.5); negative relationships were recorded microplankton CATP, CCl with temperature (r = -0.42, -0.85) and salinity (r = -0.68, -0.41). At the second bioproductivity depth maximum (50 m), significant relationships were established between HPI and temperature (r=0.64); a negative relationship was found with pH (r = -0.44). The continuity of ATP and chlorophyll a concentrations distribution with depth was shown in the 30-m layer; the heterogeneity of HPI distribution with depth was revealed as well.Finally, the research based on our own instrumental measurements shows a low productivity in the western part of the Equatorial Atlantic in winter 2022. This is caused by the features of water circulation and chemical parameters distribution.

Abstract IA013: Delivering an effective community-driven model to reduce cancer risk at a population level: results from MD Anderson’s Be Well Communities

Abstract Be Well Communities™ is The University of Texas MD Anderson Cancer Center’s place-based strategy for cancer prevention and control, working with communities to promote wellness and reduce modifiable risk factors for cancer. This initiative builds cross-sector partnerships and drives systems change for health by uniting individuals, schools, workplaces, government agencies, health care providers and policymakers to plan and carry out sustainable, community-led solutions that will make positive, long-lasting changes in people’s lives. Be Well Communities is built on 100 years of healthy community initiative best practices, literature, and experience and is aligned with the institution’s strategy and community outreach and engagement efforts. Since 2016, MD Anderson’s Cancer Prevention & Control Platform built a model that creates strong community linkages, advances professional and policy changes, and establishes active health coalitions. Community-driven coalitions ensure that interventions are executed in alignment with the priorities and needs of the community. Key components of effective community-based efforts include creating a shared vision and building trust with the community, creating a diverse network of partners through relationship building and mutual accountability, establishing a governing process with a grassroots component, and leveraging resources, training, and commissioning technical expertise where necessary. Additional components of the model include community assessment, planning, and a multi-year implementation phase – with a vision towards sustainability and evaluation throughout. Foundational to the work is partnership with community-based organizations and clinics who are supported to enhance their capacity to deliver and evaluate evidence-based interventions that are tailored directly to the needs of the community. Together with community partners, this work is positively impacting communities across the Greater Houston Area. More than 50 local, regional and state organizations are actively engaged on Be Well Communities coalitions, guiding the implementation of action plans in partnership with community residents. Since 2017, key milestones include: 7+ million pounds of healthy food distributed 27 sunshades installed at city parks, schools and college campuses 79,000+ students participated in school-based health and physical activity programs 10,000+ college students, staff and faculty have access to tobacco-free education and resources 24 free vaccination clinics hosted 1,900 cancer screenings provided in 12 months Further, for the most mature community in the portfolio, 90% of all interventions were completed or sustained. This collaborative approach, led by the wants and needs of the community, has established an infrastructure that is addressing its short-term goals and promises to improve long-term, cancer-related outcomes in communities. Aligning across sectors with a shared vision, fundamentally changing the way groups work together, is the building block for creating systems change for health. Citation Format: Ruth Rechis. Delivering an effective community-driven model to reduce cancer risk at a population level: results from MD Anderson’s Be Well Communities. [abstract]. In: Proceedings of the AACR Special Conference: Precision Prevention, Early Detection, and Interception of Cancer; 2022 Nov 17-19; Austin, TX. Philadelphia (PA): AACR; Can Prev Res 2023;16(1 Suppl): Abstract nr IA013.

Heterogeneous question answering community detection based on graph neural network

Topic-based communities have gradually become a considerable medium for netizens to disseminate and acquire knowledge. These communities consist of entities (actual objects, e.g., a real answer or an actual question) with different types (users, questions and answers) and are usually hidden and overlapping. Nowadays, prevalent community question answering (CQA) platforms have formed mature communities by manually marked topics and extensive accumulated user behavior. However, the ever-growing various entities and complex overlapping topic communities make it inefficient to manually label entity tags (e.g., Question labels supplement domain features; Potential user tags indicate the user's specialty.). Therefore, there is an urgent need for a mechanism that automatically finds hidden semantic communities from user social behavior and lays a foundation for community construction and intelligent recommendation of QA platforms. In this paper, we propose a Heterogeneous Community Detection Approach Based on Graph Neural Network, called HCDBG, to detect heterogeneous communities in CQA. Firstly, we define entity relationships based on user interaction behavior and employ a heterogeneous information network to uniformly represent all connections. Afterward, we exploit the heterogeneous graph neural network to fuse content and topological features of nodes for graph embedding. Finally, we convert the community detection issue in CQA into an entity clustering task in the heterogeneous information network and improve the k-means method to achieve heterogeneous community detection. Based on our knowledge of the existing literature, it is an innovative research direction that utilizes the heterogeneous graph neural network to facilitate QA community detection. Extensive experiments on authentic question-answering datasets illustrate that HCDBG outperforms baseline methods in heterogeneous community detection.

Extracellular Vesicles Contribute to Mixed-Fungal Species Competition during Biofilm Initiation.

Extracellular vesicles commonly modulate interactions among cellular communities. Recent studies demonstrate that biofilm maturation features, including matrix production, drug resistance, and dispersion, require the delivery of a core protein and carbohydrate vesicle cargo in Candida species. The function of the vesicle cargo for these advanced-phase biofilm characteristics appears to be conserved across Candida species. Mixed-species interactions in mature biofilms indicate that vesicle cargo serves a cooperative role in preserving the community. Here, we define the function of biofilm-associated vesicles for biofilm initiation both within and among five species across the Candida genus. We found similar vesicle cargo functions for several conserved proteins across species, based on the behavior of mutants. Repletion of the adhesion environment with wild-type vesicles returned the community phenotype toward reference levels in intraspecies experiments. However, cross-species vesicle complementation did not restore the wild-type biology and in fact drove the phenotype in the opposite direction for most cross-species interactions. Further study of mixed-species biofilm adhesion and exogenous wild-type vesicle administration similarly demonstrated competitive interactions. Our studies indicate that similar vesicle cargoes contribute to biofilm initiation. However, vesicles from disparate species serve an interference competitive role in mixed-Candida species scenarios. IMPORTANCE Candida species commonly form mixed-species biofilms with other Candida species and bacteria. In the established biofilm state, vesicle cargo delivers public goods to support the mature community. At biofilm initiation, however, vesicles play a negative role in cross-species interactions, presumably to allow species to gain a survival advantage. These observations and recent reports reveal that vesicle cargo has both cooperative and competitive roles among Candida species, depending on the needs of the community biofilm formation.

Bacterial community of sediments under the Eastern Boundary Current System shows high microdiversity and a latitudinal spatial pattern

The sediments under the Oxygen Minimum Zone of the Eastern Boundary Current System (EBCS) along Central-South Peru and North-Central Chile, known as Humboldt Sulfuretum (HS), is an organic-matter-rich benthic habitat, where bacteria process a variety of sulfur compounds under low dissolved-oxygen concentrations, and high sulfide and nitrate levels. This study addressed the structure, diversity and spatial distribution patterns of the HS bacterial community along Northern and South-Central Chile using 16S rRNA gene amplicon sequencing. The results show that during the field study period, the community was dominated by sulfur-associated bacteria. Indeed, the most abundant phylum was Desulfobacterota, while Sva0081 sedimentary group, of the family Desulfosarcinaceae (the most abundant family), which includes sulfate-reducer and H2 scavenger bacteria, was the most abundant genus. Furthermore, a spatial pattern was unveiled along the study area to which the family Desulfobulbaceae contributed the most to the spatial variance, which encompasses 42 uncharacterized amplicon sequence variants (ASVs), three assigned to Ca. Electrothrix and two to Desulfobulbus. Moreover, a very high microdiversity was found, since only 3.7% of the ASVs were shared among localities, reflecting a highly diverse and mature community.

Convergence of biofilm successional trajectories initiated during contrasting seasons.

Biofilm communities play a major role in explaining the temporal variation of biogeochemical conditions in freshwater ecosystems, and yet we know little about how these complex microbial communities change over time (aka succession), and from different initial conditions, in comparison to other stream communities. This has resulted in limited knowledge on how biofilm community structure and microbial colonization vary over relevant time scales to become mature biofilms capable of significant alteration of the freshwater environment in which they live. Here, we monitored successional trajectories of biofilm communities from summer and winter in a headwater stream and evaluated their structural state over time by DNA high-throughput sequencing. Significant differences in biofilm composition were observed when microbial colonization started in the summer vs. winter seasons, with higher percentage of algae (Bacillariophyta) and Bacteroidetes in winter-initiated samples but higher abundance of Proteobacteria (e.g., Rhizobiales, Rhodobacterales, Sphingomonadales, and Burkholderiales), Actinobacteria, and Chloroflexi in summer-initiated samples. Interestingly, results showed that despite seasonal effects on early biofilm succession, biofilm community structures converged after 70 days, suggesting the existence of a stable, mature community in the stream that is independent of the environmental conditions during biofilm colonization. Overall, our results show that algae are important in the early development of biofilm communities during winter, while heterotrophic bacteria play a more critical role during summer colonization and development of biofilms.

Footprint of the plastisphere on freshwater zooplankton

Changes in the functional groups of zooplankton were studied in autumn in a temperate floodplain lake (Lake Sakadaš, Kopački Rit Nature Park, Croatia) and in the Drava River (in the Croatian part of the river). Various abiotic parameters as well as available food sources (phytoplankton and microphytes (algae and cyanobacteria) developing on epixylon, epilithon and artificially introduced microplastics called “plastisphere”) were also studied. The lake was hydrologically isolated from the main river during the study, while the water level of the Drava River fluctuated, resulting in larger variations in limnological parameters. Due to stable conditions in the lake, zooplankton abundance, biomass, and species richness were higher than in the Drava River. In both environments, zooplankton species feeding on bacteria, detrital suspensions, and small algae were most abundant, with predators and microfilter-feeders being more abundant in the lake. Microphytes were diverse and mostly small and medium-sized in phytoplankton and all substrate types. Stable lake conditions promoted higher abundance of the zooplankton group, which effectively uses larger algae as a food source. The lower abundance of zooplankton feeding on larger algae and predatory species in the river suggests that the epilithon and plastisphere community was a less mature community compared to the lake, and the heterotrophic component with ciliates and/or other small heterotrophs was not well developed. The importance of plastispheres was particularly evident under the turbid hydrologic conditions that prevailed in the river at the end of the study, when phytoplankton biomass decreased and zooplankton abundance steadily increased, suggesting that microphytes colonised on microplastics were an additional food source for higher trophic levels.

Microbiological Analysis and Metagenomic Profiling of the Bacterial Community of an Anthropogenic Soil Modified from Typic Haploxererts

This work aimed to characterize the microbial communities of an anthropogenic soil originating from application of pedotechniques to Vertisols in a Mediterranean environment. Bare soil profiles were sampled at three depths (0–10 cm, 10–30 cm, and 30–50 cm) and compared with the original soil not transformed at the same depths. The anthropogenic soils were characterized by a higher CaCO3 concentration (360–640 g/kg) than control soil (190–200 g/kg), while an opposite trend was registered for clay, where control soil showed a higher concentration (465 g/kg on average) than anthropogenic soil (355 g/kg on average). Organic carbon content was much higher in the untransformed soil. All samples were microbiologically investigated using a combined culture-dependent and -independent approach. Each pedon displayed a generally decreasing level with soil depth for the several microbial groups investigated; in particular, filamentous fungi were below the detection limit at 30–50 cm. To isolate bacteria actively involved in soil particle aggregation, colonies with mucoid appearance were differentiated at the strain level and genetically identified: the major groups were represented by Bacillus and Pseudomonas. MiSeq Illumina analysis identified Actinobacteria and Firmicutes as the main groups. A high microbial variability was found in all the three anthropogenic pedons and the microorganisms constitute a mature community.

Construction of a Physical and Medical Care Integrated Model for the Elderly in the Community Based on Artificial Intelligence and Machine Learning.

With the increasingly serious population aging, economic system transformation, and social transformation, the elderly have an increasingly strong demand for the elderly care service industry, but the development of China's elderly care service industry started late, and there are still many problems. For how to build a better elderly care service model, under the current situation of shortage of elderly care resources, community elderly care may become a solution. By analyzing the status quo, existing problems and development trends of home-based care services in Hangzhou's community, and learning from foreign experience, it explores the establishment of a “integrated physical, medical, and nursing care” community health management model for the elderly and provides a perfect solution for the development of Hangzhou's community elderly care services countermeasures and suggestions for mode operation. Based on the evaluation, problem analysis, and empirical research on the current situation of home care services in Hangzhou communities, this paper draws on relatively mature community care practices, proposes to build a community elderly health management model that combines medical care and care, and improves and innovates the overall design and medical care of the elderly service model measures for the health management of the elderly in the integrated community. The experimental results of this study show that, according to the demand for elderly care services, elderly people in need of care account for 86.6%, 79.5%, and 68.4% of the elderly population, especially in the areas of medical care, life care, and housekeeping services.