Variation In Relative Abundance Research Articles

Variation in Relative Abundance of Small Mammal Species Caught in Two Different Ecosystems and Implicated in the Spread of Emerging Pathogens in Mali

Background: Small rodents and insectivores are potential reservoirs of many pathogens transmissible to humans, such as bacteria, parasites and viruses responsible for epidemics in sub-Saharan Africa, particularly in West Africa. Few studies on small mammal species in West Africa are available. Our previous findings from a study investigating emerging pathogens in two localities in Mali has determined the prevalence of pathogens in small mammals (rodents and insectivores). We used the data collected from this small mammal population with different eco-climatic characteristics to test hypothesis that small mammal distribution in different eco-climatic settings could explain the diversity and frequency of pathogens they carry. Methods: Sessions of trapping were carried out in December 2016 in Faladjè and Bougouni with “Besançon tous services” (BTS) wire mesh traps baited with peanut butter and/or onion. All animals captured were identified morphologically. Results: Out of 123 small rodents and insectivores captured over 674 trap-nights, 75 (60.97%) were from Faladjè and 48 (39.02%) from Bougouni. Of these, six species of small rodents belonged to the family Muridae (Mastomys erythroleucus, Mastomys natalensis, Rattus rattus, Praomys daltoni, Gerbilliscus gambianus, Taterillus gracilis) and two species of insectivores associated with the genus Crocidura spp. belonged to the family Soricidae and Erinaceidae (Crocidura cf olivieri and Atelerix cf albiventris), respectively. There is low species diversity within these two areas, but the variation in relative abundance is significant (binomial test, p ˂ 0.05) between Faladjè and Bougouni. Mastomys erythroleucus was the most dominant species (57.33%, 43/75) in Faladjè, while R. rattus dominated (37.5%,18/48) in Bougouni. Conclusions: These two species of small mammals potentially involved in the transmission of bacteria, parasites and pathogenic viruses to humans are differently present in two distinct eco-climatic areas in Mali.

Variability of the Microbiota in Chronic Rhinosinusitis: A Scoping Review.

Chronic rhinosinusitis (CRS) is characterized by a persistent inflammation of the nasal and paranasal sinus mucosa that could be potentially linked to a dysregulation between the microbiota and the immune system. We aim to explore general, methodological, and microbiological aspects of microbiota research in CRS compared to disease-free individuals. Embase, Ovid MEDLINE, PubMed, Scopus, and Web of Science. All studies comparing the composition of the resident microbiota of the sinonasal cavities in 2 groups: CRS and normal participants. We conducted systematic study selection, data extraction, and analysis first using the title and abstract, and then the full texts based on predefined inclusion and exclusion criteria. Compiled and presented findings include sampling site and technique, and microbiological results such as the relative abundance and the variability of the composition of the microbiota in both groups. Twenty-seven studies, using genomic identification with 16s RNA were analyzed. Case definitions primarily followed EPOS or AAO-HNS guidelines, with endoscopic swabs (82%), and middle meatus sampling (74%) being prevalent techniques. Despite relative abundance variability, patterns emerged across studies, indicating an increase in Haemophilus (19%) and Pseudomonas (11%), and decrease in Propionibacterium (15%) and Anaerococcus (11%). Another pattern was observed, showing a decreased alpha diversity (6/19; 22%) in CRS compared to normal individuals. While variations exist among studies, analysis of CRS microbiota suggests an association with dysbiosis, potentially contributing to chronic inflammation. Future research must prioritize standardized criteria for diagnostics and patient selection, fostering a more comprehensive understanding of CRS microbiota.

Butterflies, bumblebees and hoverflies are equally effective pollinators of Knautia arvensis (Caprifoliaceae), a generalist plant species with compound inflorescences

AbstractPlant‐pollinator interactions exist along a continuum from complete specialisation to highly generalised, that may vary in time and space. A long‐held assumption is that large bees are usually the most effective pollinators of generalist plants. We tested this by studying the relative importance of different groups of pollinators of Knautia arvensis (L.) Coult. (Caprifoliaceae: Dipsacoideae). This plant is suitable for such a study because it attracts a diversity of flower visitors, belonging to different functional groups. We asked whether all functional groups of pollinators are equally effective, or if one group is most effective, which has been documented in other species with apparently generalised pollination systems. We studied two subpopulations of K. arvensis, one at low and one at high density in Northampton, UK. To assess pollinator importance we exposed unvisited inflorescences to single visits by different groups of pollinators (butterflies, bumblebees, hoverflies and others) and assessed the proportion of pollinated stigmas. We then multiplied the effectiveness of each pollinator group with their proportional visitation frequency in five different years. For each group we also compared time spent on flowers and flight distance between visits. The relative importance of each pollinator group varied between years, as did their flight distances between flower visits. Butterflies were the best pollinators on a per visit basis (in terms of the proportion of stigmas pollinated) and flew further after visiting an inflorescence. Different measures and proxies of pollinator effectiveness varied between taxa, subpopulations, and years, and no one group of pollinators was consistently more effective than the others. Our results demonstrate the adaptive value of generalised pollination strategies when variation in relative abundance of different types of pollinators is considered. Such strategies may have buffered the ability of plants to reproduce during past periods of environmental change and may do so in the future.

Lessons learned during a 12-year monitoring project with the endangered Magdalena River turtle (Podocnemis lewyana): hunting pressure, habitat degradation, and methodological considerations

Turtle species in the Family Podocnemididae, including the Colombian endemic and critically endangered Magdalena River Turtle Podocnemis lewyana, characteristically present low recapture rates that preclude estimation of population parameters using maximum likelihood modeling. In our 12-year monitoring project with this species, we evaluated changes in relative abundances, proportions of sex/size classes, and individual body sizes and body conditions in a population in four channels in the middle Magdalena River drainage. We also inspected for associations between trends in changes in these variables and differences in hunting pressure and habitat degradation. To inspect for temporal and spatial demographic dynamics, we estimated variation in relative abundances using the Catch Per Unit Effort index, the total number of turtles captured over an entire 5-day sampling period using ten baited funnel traps. Relative abundances and the proportions of sex/size classes were different between sites and years. We found a significant decline in the proportion of females and juveniles over time, along with evidence that the females still present were smaller in body size. Our results support the hypothesis that hunting eliminates adult females from these sites, perhaps also translating into a reduction in recruitment. The lack of evidence of generalized declines in body condition of all size classes suggests that habitat degradation might contribute less to the population declines in this region. Our results also illustrate that even when recapture rates are low, monitoring turtles via standardized trapping may yield insights into the population’s conservation status that other relative abundance indices cannot.

Comparison of Juvenile Pacific Salmon abundance, distribution, and body condition between Western and Eastern Bering Sea using spatiotemporal models

Recent changes in climate have had generally negative impacts on salmon stocks in the eastern and positive effects in the western Bering Sea (WBS). Eastern Bering Sea (EBS) salmon stocks have periodically experienced reduced productivity, size, and survival, whereas salmon stocks in the western Bering Sea (WBS) have tended to be more stable, with some stocks increasing in abundance. This difference could be partially attributed to the different habitats that juvenile salmon occupy during their first marine year, which often determines recruitment. Here, we used salmon surveys in the EBS and WBS to compare the status of juveniles in these two large marine ecosystems. We applied spatio-temporal vector autoregressive spatio-temporal (VAST) models to adjust for differences in timing, vessels and trawl gear used, and to compare the relative abundance and body condition indices (length, weight, and Fulton's condition factor) of three juvenile salmon species pink, chum and sockeye salmon (Oncorhynchus gorbuscha, O. keta, and O.nerka respectively) between the WBS and EBS from 2002 to 2022. Juvenile salmon in WBS exhibited a consistent trend of larger size and higher Fulton's condition factor, with greater abundance compared to EBS in even years. A clear even-odd year pattern, which is believed to be driven by pink salmon, occurred in all species’ relative abundance and body condition in the WBS, with a limited impact of interannual temperature changes. Conversely, temperature had a significant impact on EBS salmon, with much of the variation in relative abundance and body condition occurring between warm and cold periods, and even/odd patterns were found only in pink salmon relative abundance and body condition. We detected different WBS-EBS migration patterns, with EBS juveniles dispersing from nearshore habitats earlier than WBS juveniles but migrating offshore later that is connected to bathymetry and the broad shelf in the EBS.

A New Rare Halogenated Depside from Lichen and Study of its Anti-Proliferative Activity.

Lichens are a symbiotic association of algae and fungus, belonging to the family Parmeliaceae. Some lichen species are edible and used as an active ingredient for preparation of exotic spices as well as folklore medicine to cure different kinds of ailments. A specimen of lichen was collected from Munner in the Kerala State of South India for chemical profiling. Chemical analyses of the diethyl ether extract of the defatted lichen led to the isolation of six phenols 1-6 with variation of relative abundance. Amongst them, the relative abundance of compound 3 was the greatest (1 % of crude extract) and it was identified as atranorin. The structures of known compounds were confirmed by comparison of their 1H-NMR, 13C NMR, and mass data with published values available in the literature. In vitro bioassay for anti-proliferative activity of these compounds has been conducted against various human cancer cell lines in comparison with paclitaxel as control using SRB assay. Interestingly, a new compound 5 was found along with previously reported compounds from this lichen. This new compound was designated as fluoroatranorin 5 which was reported for the first time herein. The structural characterization of a new depside was determined by spectral methods such as 1H-NMR, 13C NMR, 19F NMR, IR, LC-HRESI-MS, and LC-MS/MS study. Its structure was confirmed by single crystal X-ray diffraction study. This new compound was designated as fluoroatranorin 5 which was reported first time herein. Anti-proliferative activity of all these compounds was evaluated against six different cancer cell lines. The inhibitory activity, IC50 value of compounds 1-3 and 5 exhibited at 99.64, 102.04, 109.20, 53.0 and 2.4 μM on cancer cell lines HT-29 (colon), Hela (cervical), HT-29, HPAC (pancreas) and A2780 (ovarian cancer cell line) respectively in comparison with paclitaxel as control. The new compound 5 exhibited significant activity with IC50 value 2.4 μM on A2780 ovarian cancer cell line.

Imprints of ecological processes in the taxonomic core community: an analysis of naturally replicated microbial communities enclosed in oil.

It is widely assumed that a taxonomic core community emerges among microbial communities from similar habitats because similar environments select for the same taxa bearing the same traits. Yet, a core community itself is no indicator of selection because it may also arise from dispersal and neutral drift, i.e. by chance. Here, we hypothesize that a core community produced by either selection or chance processes should be distinguishable. While dispersal and drift should produce core communities with similar relative taxon abundances, especially when the proportional core community, i.e. the sum of the relative abundances of the core taxa, is large, selection may produce variable relative abundances. We analyzed the core community of 16S rRNA gene sequences of 193 microbial communities occurring in tiny water droplets enclosed in heavy oil from the Pitch Lake, Trinidad and Tobago. These communities revealed highly variable relative abundances along with a large proportional core community (68.0 ± 19.9%). A dispersal-drift null model predicted a negative relationship of proportional core community and compositional variability along a range of dispersal probabilities and was largely inconsistent with the observed data, suggesting a major role of selection for shaping the water droplet communities in the Pitch Lake.

Seasonal changes of ammonia-oxidizing bacterial communities during tropical forest restoration

In this study, we used a high-throughput sequencing technology to survey the dry-wet seasonal change characteristics of soil ammonia-oxidizing bacteria (AOB) communities in the three restoration stages [i.e., Mallotus paniculatus community (early stage), Millettia leptobotrya community (middle stage), and Syzygium oblatum community (later stage)] of Xishuangbanna tropical forest ecosystems. We analyzed the effects of soil physicochemical characteristics on AOB community composition and diversity during tropical forest restoration. The results showed that tropical forest restoration significantly affected the relative abundance of dominant AOB phyla and their dry-wet seasonal variation. The maximum relative abundance of Proteobacteria (71.3%) was found in the early recovery stage, while that of Actinobacteria was found in the late recovery stage (1.0%). The abundances of Proteobacteria and Actinobacteria had the maximum ranges of dry-wet seasonal variation in the early and late stages, respectively. The abundance of dominant AOB genera and its dry-wet seasonal variation varied across tropical forest restoration stages. The maximum average relative abundance of Nitrosospira and Nitrosomonas in the late recovery stage was 66.2% and 1.5%, respectively. In contrast, the abundance of Nitrosovibrio reached its maximum (25.6%) in the early recovery stage. The maximum dry-wet seasonal variation in relative abundance of Nitrosospira and Nitrosomonas occurred in the early recovery stage, while that of Nitrosovibrio occurred in the middle recovery stage. The Chao1, Shannon, and Simpson diversity indices of AOB communities increased along the restoration stages, which were significantly higher in the wet season than in the dry season. The results of canonical correspondence analysis showed that soil easily oxidized carbon was the main factor controlling AOB community diversity and Actinobacteria abundance. Soil bulk density and temperature were the main factors affecting Proteobacteria abundance. Soil pH, microbial biomass carbon, water content, ammonium nitrogen, bulk density, and temperature were the main factors controlling the abundances of Nitrosospira, Nitrosomonas, and Nitrosovibrio. Therefore, tropical forest restoration can regulate the change of relative abundance of dominant AOB taxa via mediating the changes of soil temperature, bulk density, and readily oxidized carbon, leading to an increase in soil AOB community diversity.

Mechanisms Involved in the Antihypertensive Effects of Arbequina Table Olives

The Mediterranean Diet is associated with antihypertensive properties and prevention of cardiovascular disease. This dietary pattern includes the intake of Olea europaea L. derivatives such as extra virgin olive oil and table olives, characterized by a high content of bioactive compounds. Recently, it has been demonstrated that the supplementation of Arbequina table olives (AO) reduces blood pressure (BP) in spontaneously hypertensive rats (SHR). The aim of the present study was to elucidate the possible mechanisms involved in the antihypertensive effects of AO. Consequently, we have studied different plasmatic biomarkers (angiotensin II, Ang II; malondialdehyde, MDA; interleukin 6, IL6; tumor necrosis factor α, TNFα) and the fecal microbiota composition. Experiments were performed using male SHR from 14 to 21 weeks of age. SHR strain was divided into a control (SHR-c) and a treated group (SHR-o) that received water or AO (3.85 g/kg) by gavage, respectively. At the end of the experiment, BP was measured using a non-invasive automatic analyzer; Ang II, IL6, and TNFα were determined by Elisa, and MDA by spectrophotometric analysis. Fecal microbiota was analyzed by sequencing 16S rRNA gene using the Illumina MiSeq platform. Data were analyzed by t-Student or the Mann–Whitney U test, and statistical significance was considered when p<0.05. AO supplementation decreased systolic and diastolic BP by approximately 19 mmHg in SHR-o with respect to SHR-c. The decrement in BP was accompanied by a decrease in MDA (39%) and Ang II (32%) in SHR-o without changes in the concentrations of the proinflammatory cytokines IL6 and TNFα. Moreover, regular AO intake induced changes in the microbiota associated with the normalization of BP. Our results showed variations in relative abundance in genera such as Akkermansia, Sutterella, and Peptoniphilus, that were well correlated with the decrease in BP, MDA, and Ang II. In conclusion, OA supplementation reduced oxidative stress and Ang II associated with changes in the fecal microbiota that may explain the antihypertensive effect elicited by consumption of the fruit of Olea europaea L. Supported by grants AGL2013-41188 & 2021SGR300. INSA Maria de Maeztu Unit of Excellence grant CEX2021-001234-M. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Ecological impact of mechanical cleaning method to curb black stain alterations on Paleolithic cave walls

Anthropization of Paleolithic karstic caves can cause an imbalance of cave microbiota and may trigger formation of wall alterations including black stains. In Lascaux Cave, a previous attempt to mechanically remove black stains was followed by reformation of the stain in months, suggesting that microbial recolonization had taken place. On this basis, we hypothesized that mechanical cleaning (a routine cleaning method for conservation of heritage sites) leaves a residual microbial community that can also serve as pioneer community, i.e. a community of early microbial residents that triggers subsequent microbial successions involved in the reformation of black stains. We monitored post-cleaning microbial recolonization over 19 months in the Apse of Lascaux Cave (France), after using two methods of mechanical cleaning (scalpel alone, or scalpel + sponge). Illumina MiSeq metabarcoding evidenced various taxa i.e. the bacteria Pseudomonas, Pedomicrobium and black-melanized fungi Ochroconis (=Scolecobasidium) during early recolonization of cleaned surfaces, and at later stages the establishment of several other taxa including the bacteria Luteimonas, Chitinophaga and the black fungus Exophiala. Surfaces at 19 months after cleaning were visually and microbiologically different from stained surfaces immediately after cleaned and from unstained surfaces, but also from non-cleaned stained surfaces, probably because of a particular microbial succession, distinct from the original succession during stain formation. Variations in relative abundance of Bacteroidota and Eurotiomycetes classes and Exophiala genus were higher when the sponge was used in addition to the scalpel. The bacteria Filomicrobium and the fungi Isaria and Cephalotrichum were identified on sponge-cleaned surfaces and on the sponge itself, pointing to a contaminant status due to the cleaning method. Overall, it suggests that post-cleaning pioneer communities may play an important role in orienting stain reformation in caves. Sponges routinely used by restorers to curb microbial stains may bring microbial contaminants, which questions current cleaning practices in show caves.

Effect of storage on microbioa and enzyme proteomic profile of low-temperature Daqu

Daqu provides microbiota, flavor substances and enzymes for liquor fermentation. Storage after fermentation is an essential stage for the mature of Daqu. However, it is still unclear about the effect of storage on the microbiota structure and enzyme profile. Here, this work revealed the variation of microbiota structure and enzyme profile after storage of low-temperature Daqu using amplicon sequencing and proteomic profile analysis. Results showed that the content of acidity significantly increased by 13.79% (P ＜0.05). The saccharification power, liquefaction power and fermentation power significantly increased by 2.90%, 17.32% and 16.04%, respectively (P ＜0.05). The contents of 3-methyl-1-butanol and 1-octen-3-ol increased by 147.19% and 29.12%, respectively (P ＜0.05). Lichtheimia, Saccharomyces, Rhizopus, Aspergillus, Pantoea, Lactiplantibacillus, Pichia, Lacticaseibacillus, Pseudomonas, Linnemannia, Levilactobacillus, Pediococcus, Paenibacillus and Lactobacillus were the major enzyme-producing microbiota (average protein abundance >1%) using proteomic profile analysis. After storage, the relative abundances of Lactobacillus and Aspergillus increased from 2.59% to 17.63%, and 7.53%–33.67% using amplicon sequencing, respectively. The protein abundance of α-amylase produced by Aspergillus increased from 0.05% to 0.11%, and was consistent with variations of the relative abundance of Aspergillus, and the liquefaction power. The protein abundance of lactic acid dehydrogenase produced by Lactobacillus increased from 0.07% to 0.11%, and was consistent with the variation of relative abundance of Lactobacillus. This work revealed the effect of storage on microbioa and enzyme proteomic profile of low-temperature Daqu. It would be beneficial for controlling the storage stage of Daqu, and help improving the quality of Daqu.

Phenotypic plasticity, and temporal and spatial variation in the relative abundance of lentic brook trout, Salvelinus fontinalis, across Ontario.

Brook trout (Salvelinus fontinalis) are a highly prized species found in lakes and streams throughout Ontario. A broadscale monitoring program (BsM) has been conducted in lakes throughout the province, in 5-year cycles, which targets Salvelinus fontinalis populations. The objective of this study was to use the data gained from the BsM and establish a contemporary baseline on the variation of relative abundance and demographics of natural lake populations of S. fontinalis in Ontario. Additionally, given the variability in environmental conditions across the landscape, an objective was to assess the factors, abiotic and biotic, that influence relative abundance among waterbodies. Over the three BsM cycles (2008-2022), 273 S. fontinalis waterbodies were assessed, some multiple times, and 124 were unique populations. S. fontinalis were sampled in 112 of these unique lakes. In total, 7487 S. fontinalis were caught and 5372 were fully sampled (length, weight, and age assessed). The mean catch-per-unit-effort (CPUE) in all waterbodies was 1.4 (0.12 standard error) S. fontinalis per net gang. There was not a significant trend in CPUE over the three BsM cycles nor did CPUE vary significantly among BsM cycles at the provincial scale, but CPUE varied significantly among fisheries management zones (FMZs). Multiple variables were examined to explain the variation in CPUE across the province; a negative association with species diversity was the only variable considered significant. Furthermore, S. fontinalis were more associated with the relative abundance of small cyprinids (i.e., chubs and shiners) and negatively associated with centrarchids, smelt, and other game species. Mean growth potential was greater for males than females but not significantly, whereas longevity favored females. Growth potential and parameters were similar between sexes within FMZs but varied among FMZs. Mean survival among these populations was 25.7%, ranging from 15.2% to 45.6%, with a mean instantaneous mortality of 1.41. This study provided a contemporary assessment of the current range and variability in relative abundance population dynamics of S. fontinalis in lakes within Ontario. This provides a benchmark to assess changes with the pending stressors of climate change and human expansion across the landscape.

Exploring the bladder tissue microbiome in patients with muscle-invasive bladder cancer using 2bRAD-M sequencing

Abstract Objectives The 2bRAD sequencing for Microbiome (2bRAD-M) represents an innovative and streamlined approach for the reconstruction of microbial profiles at the species level. In our investigation, we conducted 2bRAD-M analysis to characterize the microbiome of bladder tissue in patients with muscle-invasive bladder cancer (MIBC). Methods 15 tumor tissues and 15 paired para-carcinoma tissues were obtained from the bladder excised during surgery. 2bRAD-M sequencing was used to assess the abundance of microorganisms in samples. Results The microbial community structure and biodiversity, as assessed at varying taxonomic ranks, exhibited a high degree of similarity between the tumor and paired non-tumor tissues. At the genus level, we observed a notably elevated abundance of Brachybacterium and Haloparvum, coupled with a diminished abundance of Anoxybacillus, Anoxybacillu_A, Deinococcus, NCEH01, and Pseudoxanthomonas_A in the tumor tissues. Meanwhile, at the species level, the non-tumor tissues exhibited an enrichment of Anoxybacillus_A rupiensis, Anoxybacillus flavithermus_G, Klebsiella quasipneumoniae, NCEH01 sp002304505, and Pseudoxanthomonas_A sp004284195. Linear discriminant analysis effect size (LEfSe) identified 29 discriminative features, characterized by significant variations (p<0.5, LDA≥2.0) in relative abundance between the two groups. Furthermore, an analysis of functional predictions utilizing Phylogenetic Investigation of Communities by Reconstruction of Unobserved States 2 (PICRUSt2) also uncovered disparities in the microbial functional composition. Conclusions This study identified several microorganisms that exhibit differences between MIBC tumor tissue and adjacent non-tumor tissue using 2bRAD-M sequencing, providing some insights into the potential association between the bladder microbiome and cancer.

Spread and persistence of antimicrobial resistance genes in wastewater from human and animal sources in São Paulo, Brazil.

The spread of antimicrobial resistance (AMR) through multiple reservoirs is a global concern. Wastewater is a critical AMR dissemination source, so this study aimed to assess the persistence of resistance genetic markers in wastewater using a culture-independent approach. Raw and treated wastewater samples (n = 121) from a wastewater treatment plant (WWTP), a human hospital, a veterinary hospital, and a pig farm were monthly collected and concentrated by filtration. DNA was extracted directly from filter membranes, and PCR was used in the qualitative search of 32 antimicrobial resistance genes (ARGs). Selected genes (blaCTX-M, blaKPC, qnrB, and mcr-1) were enumerated by quantitative real-time PCR (qPCR). Twenty-six ARGs were detected in the qualitative ARGs search, while quantitative data showed a low variation of the ARG's relative abundance (RA) throughout the months, especially at the human hospital and the WWTP. At the WWTP, despite significantly reducing the absolute number of gene copies/L after each treatment stage (p < 0.05), slight increases (p > 0.05) in the RAs of genes blaCTX-M, qnrB, and mcr-1 were observed in reused water (tertiary treatment) when compared with secondary effluent. Although the increase is not statistically significant, it is worth noting that there was some level of ARGs concentration after the disinfection process. No significant absolute or relative after-treatment quantification reductions were observed for any ARGs at the veterinary hospital or the pig farm. The spread of ARGs through sewage needs to be continuously addressed, because their release into natural environments may pose potential risks of exposure to resistant bacteria and impact local ecosystems.

Relation between the relative abundance and collapse of Aphanizomenon flos-aquae and microbial antagonism in Upper Klamath Lake, Oregon.

Aphanizomenon flos-aquae (AFA) is the dominant filamentous cyanobacterium that develops into blooms in Upper Klamath Lake, Oregon, each year. During AFA bloom and collapse, ecosystem conditions for endangered Lost River and shortnose suckers deteriorate, thus motivating the need to identify processes that limit AFA abundance and decline. Here, we investigate the relations between AFA and other members of the microbial community (photosynthetic and nonphotosynthetic bacteria and archaea), how those relations impact abundance and collapse of AFA, and the types of microbial conditions that suppress AFA. We found significant spatial variation in AFA relative abundance during the 2016 bloom period using 16S rRNA sequencing. The Pelican Marina site had the lowest AFA relative abundance, and this was coincident with increased relative abundance of Candidatus Sericytochromatia, Flavobacterium, and Rheinheimera, some of which are known AFA antagonists. The AFA collapse coincided with phosphorus limitation relative to nitrogen and the increased relative abundance of Cyanobium and Candidatus Sericytochromatia, which outcompete AFA when dissolved inorganic nitrogen is available. The data collected in this study indicate the importance of dissolved inorganic nitrogen combined with microbial community structure in suppressing AFA abundance.

The Relationship between the Edge Density of the Forest Fragments and the Tree Species Richness in the Detached Fragments of Kakamega Forest.

Purpose: The theoretical approach guiding this study was based on the Island Biogeography Theory. The purpose of this study was to assess the influence of the edge density of the forest fragments on tree species richness.&#x0D; Methodology: The study adopted a cross-sectional correlational research design. Proportionate random sampling was used. A sample of 30 plots each measuring 2m by 2m was established randomly in the fragments (0-200m from the edge towards the interior);Malava: Kisere: Ikuywa in that order for field sampling and measurements. Data was collected using tools such as measuring tapes,metre rule,GPS 64s Garmain and suunto inclinometer. A total of 39 species of trees were recorded from the three fragments with Funtumia africana being recorded as the most abundant species.&#x0D; Findings: The findings show 83%, 85%, and 92% variation of tree species richness in. Malava (r2 = 0.83), Kisere (r2 = 0.85) and Ikuywa (r2 = 0.92) in that order can be explained by the edge density of the fragments. The edge density also explained 87%, 94% and 94% variation of tree species relative abundance in Malava (r2 = 0.87), Kisere (r2 = 0.94) and Ikuywa (r2 = 0.94) in that order.&#x0D; Unique Contributor to Theory, Policy and Practice: It was concluded that tree species richness and tree species abundance in the detached portions of Kakamega forest were dominantly influenced by forest fragment total edge length and fragment edge density. For us to conserve more tree species we recommend maintenance of the total edge length of the fragments above 15km with edge density (3.413.79m\m2) in order to maintain high tree species richness and tree species relative abundance.

Microbial community diversity of an integrated constructed wetland used for treatment of sewage.

The microbial community diversity in Constructed Wetland System (CWS) plays a key role in the removal of pollutants from waste water. An integrated functional CWS developed at Neela Hauz Biodiversity Park, Delhi was selected to assess the diversity in composition and structure of microbial community diversity of sludge and sediment of CWS, based on metagenomic approach using 16S rRNA genes. The sediment showed higher diversity than sludge and both formed distinct clusters. The taxonomic structure of the microbial community of CWS is represented by 6,731 OTUs distributed among 2 kingdoms, 103 phyla, 227 classes, 337 orders, 320 families, 295 identified genera, and 84 identified species. The relative abundance of top 5 dominant phyla of sludge and sediment varied from 3.77% (Acidobacteria) to 35.33% (Proteobacteria) and 4.07% (Firmicutes) to 28.20% (Proteobacteria), respectively. The range of variation in relative abundance of top 5 dominant genera of sludge and sediment was 2.58% (Hyphomicrobium) to 6.61% (Planctomyces) and 2.47% (Clostridium) to 4.22% (Syntrophobacter), respectively. The rich microbial diversity of CWS makes it perform better in pollutants removal (59.91-95.76%) than other CWs. Based on the abundance values of taxa, the taxa are grouped under four frequency distribution classes-abundant (>20), common (10-19), rare (5-9), and very rare (1-4). The unique structure of microbial communities of integrated CWS is that the number of abundant taxa decreases in descending order of taxonomic hierarchy, while the number of rare and very rare taxa increases. For example, the number of abundant phyla was 14 and 21 in sludge and sediment, respectively and both communities have only 3 abundant genera each. This is in contrast to 4 and 17 very rare phyla in sludge and sediment, respectively and both the communities have 114 and 91 very rare genera, respectively. The outcomes of the study is that the integrated CWS has much higher microbial community diversity than the diversity reported for other CWs, and the rich diversity can be used for optimizing the performance efficiency of CWS in the removal of pollutants from waste water. Such structural diversity might be an adaptation to heterogeneous environment of CWS.

Microbiome changes through the ontogeny of the marine sponge Crambe crambe

BackgroundPoriferans (sponges) are highly adaptable organisms that can thrive in diverse marine and freshwater environments due, in part, to their close associations with internal microbial communities. This sponge microbiome can be acquired from the surrounding environment (horizontal acquisition) or obtained from the parents during the reproductive process through a variety of mechanisms (vertical transfer), typically resulting in the presence of symbiotic microbes throughout all stages of sponge development. How and to what extent the different components of the microbiome are transferred to the developmental stages remain poorly understood. Here, we investigated the microbiome composition of a common, low-microbial-abundance, Atlantic-Mediterranean sponge, Crambe crambe, throughout its ontogeny, including adult individuals, brooded larvae, lecithotrophic free-swimming larvae, newly settled juveniles still lacking osculum, and juveniles with a functional osculum for filter feeding.ResultsUsing 16S rRNA gene analysis, we detected distinct microbiome compositions in each ontogenetic stage, with variations in composition, relative abundance, and diversity of microbial species. However, a particular dominant symbiont, Candidatus Beroebacter blanensis, previously described as the main symbiont of C. crambe, consistently occurred throughout all stages, an omnipresence that suggests vertical transmission from parents to offspring. This symbiont fluctuated in relative abundance across developmental stages, with pronounced prevalence in lecithotrophic stages. A major shift in microbial composition occurred as new settlers completed osculum formation and acquired filter-feeding capacity. Candidatus Beroebacter blanensis decreased significatively at this point. Microbial diversity peaked in filter-feeding stages, contrasting with the lower diversity of lecithotrophic stages. Furthermore, individual specific transmission patterns were detected, with greater microbial similarity between larvae and their respective parents compared to non-parental conspecifics.ConclusionsThese findings suggest a putative vertical transmission of the dominant symbiont, which could provide some metabolic advantage to non-filtering developmental stages of C. crambe. The increase in microbiome diversity with the onset of filter-feeding stages likely reflects enhanced interaction with environmental microbes, facilitating horizontal transmission. Conversely, lower microbiome diversity in lecithotrophic stages, prior to filter feeding, suggests incomplete symbiont transfer or potential symbiont digestion. This research provides novel information on the dynamics of the microbiome through sponge ontogeny, on the strategies for symbiont acquisition at each ontogenetic stage, and on the potential importance of symbionts during larval development.

Comparative Analysis of Hindgut Microbiota Variation in Protaetia brevitarsis Larvae across Diverse Farms.

Protaetia brevitarsis larvae are farm-raised for food, are used in traditional East Asian medicine, and convert organic waste into biofertilizers. Here, the comparative analysis of the gut microbiota of third-instar larvae obtained from five different farms was investigated using 16S rRNA microbial profiling. Species richness, evenness, and diversity results using α-diversity analysis (observed species, Chao1, Shannon, Simpson) were similar between farms, except for those between the TO and KO farms. β-diversity was significantly different in distribution and relative abundance between farms (PERMANOVA, pseudo-F = 13.20, p = 0.001). At the phylum level, Bacillota, Bacteroidota, Actinomycetota, and Pseudomonadota were the most dominant, accounting for 73-88% of the hindgut microbial community. At the genus level, Tuberibacillus, Proteiniphilum, Desulfovibrio, Luoshenia, and Thermoactinomyces were the most abundant. Although oak sawdust was the main feed component, there were large variations in distribution and relative abundance across farms at the phylum and genus levels. Venn diagram and linear discriminant analysis effect size analyses revealed large variations in the hindgut microbial communities of P. brevitarsis larvae between farms. These results suggest environmental factors were more important than feed ingredients or genetic predisposition for the establishment of the intestinal microbiota of P. brevitarsis larvae. These findings serve as reference data to understand the intestinal microbiota of P. brevitarsis larvae.

Relative abundance and biometry of Bolivina ordinaria on the northern continental slope of the Pelotas basin during the late Quaternary

This study examines the variations in relative abundance, test size, and biomass of the species Bolivina ordinaria (Foraminifera) over the last 112 ka BP on the northern slope of the Pelotas Basin, Southern Brazil. The analyses were based on 651 individuals from 42 samples distributed along the cores SIS-249 (Marine Isotope Stage 5 to 3) and SIS-188 (Marine Isotope Stage 3 to 1). Bolivina ordinaria was the most abundant species of the Bolivinitidae family in these cores, particularly during warmer periods (MIS 1 and 5). Nine other species of this family were identified: B. compacta, B. doniezi, B. lowmani, Bolivina sp., B.striatula, Brizalina sp., Brizalina spinescens, Brizalina subaenariensis, and Brizalina subspinescens. Larger test lengths were observed during MIS 3 in the both cores. The summed biomass was higher during MIS 5 in the SIS-249 core and lower during MIS 3 in the SIS-188 core. The fluctuations observed in the relative abundance and summed biomass of B. ordinaria are consistent with the oscillations in total organic carbon flow, and the variations in primary productivity between the interglacial and glacial periods. The results suggest that this infaunal species is favored by the regular supply of refractory organic matter during warmer periods but faces increased competition from shallow infaunal and epifaunal species during glacial periods, when the flow of labile organic matter increases.