Bacterial Community Structure Research Articles

Atmospheric microplastic input into wetlands: Spatiotemporal patterns, drivers, and unique ecological impacts

Wetlands are major microplastic sinks with a large atmospheric input. However, many details of such deposited atmospheric microplastics entering into wetlands remain unclear, including temporal patterns of input and ecological effects. We monitored the aerial microplastics during four seasons in eleven economically developed cities along the lower reaches of the Yangtze River Basin, China. The average microplastic deposition rate was 512.31 items m−2 d−1, equivalent to an annual contribution of 17.46 metric tons of plastic to the surveyed wetlands with a total area of 1652 km2. These microplastics were predominantly composed of polyamide and polyethylene terephthalate with 61.85 ± 92.29 µm sized pellets, and we obtained similar results for microplastics intercepted on moss in wetlands. Microplastic input varied between wet and dry periods, primarily influenced by wind, rainfall and ozone concentration. Civilian vehicle density and textile industry were the primary socioeconomic factors driving microplastic deposition. Further indoor microcosm experiments revealed that moss phyllosphere bacterial community structure and function were influenced by microplastic abundance and size, exemplifying the unique ecological risks of aerially deposited microplastics to wetlands. These results indicate that mosses and their phyllosphere microbiota could serve as bio-indicators of aerial microplastic characteristics and impacts.

Integrating rhizosphere bacterial structure and metabolites with soil Cd availability in different parent paddy soils

Soil bacterial community structure and rhizosphere metabolites are important pathways for rice to respond to external Cd stress. The specific correlations between these microorganisms, metabolites and inherent soil properties, as well as the mechanisms they utilize to regulate Cd availability across different parent soils remain underexplored, emphasizing the need for deeper understanding to inform effective soil management strategies. In this study, five typical parent soils with large differences in properties (quaternary red clay soil (hereby defined as Q), granite soil (G), river sandy mud (R), yellow mud soil (Y), stucco field (S)) in Chinese paddy soils were collected, and extra Cd were added (CK: 0 mg·kg−1, Cd: 2.4 mg·kg−1).The result indicated that the toxicity impact of Cd in rice grains in G was the weakest, and the highest Cd bioavailability in S. The abundance of Proteobacteria, Bacteroidota and Firmicutes showed an increasing trend in G, while they decreased significantly in S. The contents of Cis-9-palmitoleic acid and phosphoethanolamine increased by 170.02 % and 154.03 % in G, decreased by 218.62 % and 181.58 % in S. MBNT15 and Desulfobacterota showed a significant negative correlation with humic acid molecular weight (MW) extracted from parent soils and Clay (montmorillonite, illite, kaolinite) contents, while they exhibited a positive correlation with soil organic matter (OM) content (P < 0.01). The MW played a crucial role in shaping rhizosphere metabolites with R2 value of 0.8498. These results elucidate how soil bacterial communities, rhizosphere metabolites, and inherent soil properties interact to regulate Cd availability across different parent soils.

Genetic resistance to Fusarium wilt shapes rhizospheric beneficial microbiota in four banana cultivars

This study explores the dynamics of bacterial communities in the bulk soil, rhizosphere, and endosphere of banana plants, focusing on variations among cultivars with differing levels of genetic resistance to Fusarium wilt. We examined four banana cultivars: one resistant (P), one moderately susceptible (PT), and two susceptible (W and M). Using 16S rDNA sequencing, we analyzed the bacterial community structures in these habitats. The results showed significant differences in bacterial communities across the three habitats and among the cultivars, with the endosphere communities being the most distinct. The rhizosphere and bulk soil communities were more similar, likely due to the soil microbiome's influence on the rhizosphere. Resistant cultivars (PT and P) displayed unique bacterial communities, with notable taxa such as Burkholderia, Leifsonia, and Marmoricola in the rhizosphere, known for their antagonistic properties against Fusarium oxysporum. In contrast, susceptible cultivars (W and M) harbored different dominant genera, such as Reyranella and Mucilaginibacter, which did not play significant defensive roles against Fusarium wilt. Additionally, the endosphere of resistant cultivars featured beneficial genera like Amycolatopsis and Achromobacter, known for promoting plant growth and enhancing disease resistance. The findings underscore the importance of plant genotype in shaping the rhizosphere microbiome, with specific microbial taxa linked to resistance against Fusarium. These insights point to the potential for developing targeted microbial-based strategies to enhance disease resistance and overall plant health. The study identifies key microbial players that could be harnessed for biological control and improved management of Fusarium wilt in banana cultivation. This research advances our understanding of plant-microbe interactions and their implications for sustainable agriculture, particularly in combating soilborne pathogens.

Diversity and community distribution of soil bacterial in the Yellow River irrigation area of Ningxia, China.

The bacterial community performs an essential ecological role in maintaining agriculture systems. The roles of bacteria in the forest, marine, and agricultural systems have been studied extensively and intensively. However, similar studies in the areas irrigated by the Yellow River remain limited. In this study, we used Illumina sequencing analysis with the 16S rRNA method to analyze the bacterial diversity, community structure, and influencing factors in soil samples from eight regions of the Yellow River irrigation area in northwestern China. The bacterial community structure and diversity varied among samples from the eight regions. The samples differed significantly in terms of the bacterial community composition. Proteobacteria (approximately 12.4%-55.7%) accounted for the largest proportion and was the dominant bacteria, followed by Actinobacteria (approximately 9.2%-39.7%), Bacteroidetes (approximately 1.8%-21.5%), and Chloroflexi (approximately 2.7%-12.6%). Among the physicochemical variables, the soil pH in the eight regions was mildly alkaline, and the total nitrogen, total phosphorus, and total potassium contents in the soils differed significantly. However, the trend in the variations of the above variables was essentially similar. Soil bacteria in Yongning county had greater Chao1, Shannon-Wiener, and Simpson indices than those in the other regions. Notably, soil moisture, organic matter, and total nitrogen were recognized as the primary factors influencing the bacterial community in the Yellow River irrigation area. Our results revealed the laws of variation in soil bacterial diversity and community composition in the Yellow River irrigation area. Our findings could be beneficial for maintaining sustainable ecological practices in the Yellow River irrigation area.

Differential microbiome features in lake-river systems of Taihu basin in response to water flow disturbance.

In riverine ecosystems, dynamic interplay between hydrological conditions, such as flow rate, water level, and rainfall, significantly shape the structure and function of bacterial and microeukaryotic communities, with consequences for biogeochemical cycles and ecological stability. Lake Taihu, one of China's largest freshwater lakes, frequently experiences cyanobacterial blooms primarily driven by nutrient over-enrichment and hydrological changes, posing severe threats to water quality, aquatic life, and surrounding human populations. This study explored how varying water flow disturbances influence microbial diversity and community assembly within the interconnected river-lake systems of the East and South of Lake Taihu (ET&ST). The Taipu River in the ET region accounts for nearly one-third of Lake Taihu's outflow, while the ST region includes the Changdougang and Xiaomeigang rivers, which act as inflow rivers. These two rivers not only channel water into Lake Taihu but can also cause the backflow of lake water into the rivers, creating distinct river-lake systems subjected to different intensities of water flow disturbances. Utilizing high-throughput sequencing, we selected 22 sampling sites in the ET and ST interconnected river-lake systems and conducted seasonally assessments of bacterial and microeukaryotic community dynamics. We then compared differences in microbial diversity, community assembly, and co-occurrence networks between the two regions under varying hydrological regimes. This study demonstrated that water flow intensity and temperature disturbances significantly influenced diversity, community structure, community assembly, ecological niches, and coexistence networks of bacterial and eukaryotic microbes. In the ET region, where water flow disturbances were stronger, microbial richness significantly increased, and phylogenetic relationships were closer, yet variations in community structure were greater than in the ST region, which experienced milder water flow disturbances. Additionally, migration and dispersal rates of microbes in the ET region, along with the impact of dispersal limitations, were significantly higher than in the ST region. High flow disturbances notably reduced microbial niche width and overlap, decreasing the complexity and stability of microbial coexistence networks. Moreover, path analysis indicated that microeukaryotic communities exhibited a stronger response to water flow disturbances than bacterial communities. Our findings underscore the critical need to consider the effects of hydrological disturbance on microbial diversity, community assembly, and coexistence networks when developing strategies to manage and protect river-lake ecosystems, particularly in efforts to control cyanobacterial blooms in Lake Taihu.

Sample collecting methods for bacterial community structure analysis of scalp hair: non-invasive swabbing versus intrusive hair shaft cutting

Human skin samples for microbiome analysis are traditionally collected using a non-invasive swabbing method. Here, we compared the differences in bacterial community structures on scalp hair and scalps with samples collected using non-invasive swabbing and cutting/removal of scalp hair in 12 individuals. Hair-related samples, such as hair shafts and hair swabs, had significantly higher alpha diversity than scalp swab samples, whereas there were no significant differences between hair shafts and hair swabs. The relative abundances of the three major phyla and five major operational taxonomic units were not significantly different between the hair shaft and hair swab samples. The principal coordinate analysis plots based on weighted UniFrac distances were grouped into two clusters: samples from hair-related areas and scalp swabs, and there were significant differences only between samples from hair-related areas and scalp swabs. In addition, a weighted UniFrac analysis revealed that the sampling site-based category was a statistical category but not a hair sampling method-based category. These results suggest that scalp hair bacteria collected using non-invasive swab sampling were comparable to those collected cutting/removal of scalp hair.

Permafrost-dissolved organic carbon and cladoceran grazing regulate bacterial abundance and community structure

The thawing of frozen soils has resulted in the release of tremendous amounts of organic carbon. Permafrost-derived dissolved organic carbon (DOC) has been demonstrated to be biolabile to microbes in aquatic ecosystems. Cladoceran grazing is another regulatory force that may affect the properties and/or characteristics of the bacterial community. However, the effects of permafrost DOC and cladoceran grazing on bacterial abundance, community composition, and diversity in aquatic ecosystems have rarely been explored. In this study, DOC was extracted from frozen soils adjacent to the shoreline of a pristine alpine lake and used to culture bacteria. The bacterial abundance decreased over time during the bioincubation experiment, whereas Daphnia feeding had no significant effect on the bacterial abundance. The genera Pedobacter, Novosphingobium, Flavobacterium and Limnohabitans had relatively high abundances after a 27-d bioincubation period. The overall decrease in bacterial diversity in the Daphnia grazing experiment was higher than that in the bacterial incubation experiment. The co-occurrence network demonstrated that terrestrial and microbial humic-like components C1 and C2 had strong interactions with Pseudolabrys, and tyrosine-like component C3 presented ­correlations with Hyphomicrobium and Vampirovibrio. Bacterial communities in the two experiments were significantly different. Sphingomonadales, Sphingobacteriales, Burkholderiales, and Actinomycetales were the primary contributors to these differences. Our study contributes significantly to a broader understanding of carbon cycling and microbial food web in lakes, particularly in high-altitude and polar lakes.

Impacts of an intensive traditional mariculture model on offshore environments as evidenced by dissolved organic matter and bacterial communities

Mariculture is a key protein source and economic driver but traditional methods pollute coastal waters, hindering sustainable development. Current research on the ecological impacts of mariculture mainly focuses on specific pollutants and lacks an assessment of the biogeochemical impacts of mariculture discharge. This study examined Xiangshan Bay, a representative intensive mariculture area in China, to explore the impact of mariculture tailwater discharge on water quality, focusing on dissolved organic matter (DOM) and bacterial communities. Based on the fluorescence excitation-emission matrix combined with parallel factor analysis, a characteristic fluorescence component C4 was identified in mariculture tailwater (intensity of 40 ± 4 %, n = 8), while higher C4 components (47 ± 3 %, n = 15) were found throughout the bay. Humic-like components from riverine input (C1 + C2: 32 ± 3 %, n = 15) and protein-like components from domestic sewage (C5: 2 ± 1 %, n = 15) were significantly lower in the seawater samples, indicating the strong influence of mariculture tailwater on the entire DOM structure of the bay. The bacterial community structure showed a response consistent with DOM, as revealed by nonmetric multidimensional scaling analysis. This showed that bacterial communities in mariculture tailwater and bay water samples clustered together, independent of riverine input. The SourceTracker model indicated that mariculture tailwater (91 ± 5 %) predominantly contributed to the bacterial community, with minimal contributions from riverine input (< 5 %). Co-occurrence network analysis further showed that under long-term high-intensity mariculture discharge, the C4 component became the core DOM and was closely associated with the bacterial community. The results here demonstrate the profound impact of traditional mariculture on coastal water quality and show that riverine input is not the primary pollution source in this region, providing clear directions for coastal environmental restoration efforts.

Influence of Varied Phosphorus Fertilizer Ratios on the Rhizosphere Soil Microbial Community in Idesia polycarpa Seedlings

Phosphorus (P) is crucial for tree growth and development, and it significantly influences the rhizosphere microbial community. However, the effects of phosphorus addition on the microbial communities in the rhizosphere soil of Idesia polycarpa remain understudied. In this study, two-year-old “Yuji” Idesia polycarpa seedlings were used to investigate the effects of phosphorus fertilization at four different levels of 0 g (control, CK), 0.92 g (low phosphorus, LP), 1.83 g (medium phosphorus, MP), and 2.75 g (high phosphorus, HP) per plant. The fertilizers were applied every 40 days over 120 days. MiSeq high-throughput sequencing of the 16S rRNA and ITS1 genes was employed to analyze the microbial community composition and diversity of bacteria and fungi in the rhizosphere soil under different phosphorus levels. The results showed that compared with CK treatment, the application of phosphorus fertilizer changed the physicochemical properties of the soil. The LP treatment significantly increased the soil pH, while the HP treatment group exhibited the highest soil-available phosphorus (AP) content. LP treatment significantly increased the number of microbial OTUs in the early and rapid growth stages and the richness and diversity of microbial communities. In addition, the bacterial community structure was significantly correlated with soil pH and AP, while the fungal community had no significant effect. The primary metabolic pathway function of bacteria in the rhizosphere soil of Idesia polycarpa seedlings is mainly metabolism, while fungi are mainly biosynthesis. Compared with CK treatment, 20 differential metabolic pathways were screened out in the bacterial community. Only two differential metabolic pathways were screened out in the fungal community by LP treatment at 120 days. In summary, applying low-level phosphate fertilizer is conducive to promoting the diversity of rhizosphere soil microorganisms. Therefore, potted planting of Idesia polycarpa seedlings is more suitable for applying low phosphorus levels.

Unveiling the Gut Microbiota of Pig-Tailed Macaque (Macaca nemestrina) in Selected Habitats in Malaysia.

The gut microbiota plays an important role in primates, which may be associated with their habitat. In Malaysia, pig-tailed macaques (Macaca nemestrina) live in different habitat environments and have traditionally been used for coconut plucking for more than a century. There is currently no information regarding the gut microbiota of this macaque in Malaysia. To address this oversight, this study employed a fecal metabarcoding approach to determine the gut microbiota composition of pig-tailed macaques and establish how these microbial communities correspond with the macaque external environments of residential area, forest edge, and fragmented forest. To determine this connection, 300 paired-end sequences of 16S rRNA were amplified and sequenced using the MiSeq platform. In the pig-tailed macaque fecal samples, we identified 17 phyla, 40 orders, 52 families, 101 genera, and 139 species of bacteria. The most prevalent bacterial families in the gut of pig-tailed macaques were Firmicutes (6.31%) and Proteobacteria (0.69%). Our analysis did not identify a significant difference between the type of environmental habitat and the gut microbiota composition of these macaques. There was great variation in the population richness and bacterial community structure. The abundance of Firmicutes and Proteobacteria helps this macaque digest food more easily while maintaining a healthy gut microbiota diversity. Exploring the gut microbiota provides an initial effort to support pig-tailed macaque conservation in the future.

The response of microbiome assembly within different niches across four stages to the cultivation of glyphosate-tolerant and conventional soybean varieties.

Plants are inherently connected with the microbiome, which plays a crucial role in regulating various host plant biological processes, including immunity, nutrient acquisition, and resistance against abiotic and biotic stresses. Many factors affect the interaction between plants and microbiome. In this study, microbiome samples were collected from five niches (bulk soil, rhizoplane, root endosphere, phylloplane, and leaf endosphere) across four developmental stages (seedling, flowering, podding, and maturity) of various soybean varieties. Composition and structure of bacterial and fungal communities were analyzed using 16S rRNA gene and ITS (Internally Transcribed Spacer) region amplicon sequencing. It was observed that both niches and developmental stages significantly impact on the assembly and composition of soybean microbiome. However, variety, presence of a transgene, and glyphosate application had minimal effects on microbial communities. The dominant microbiome varied across the five niches, with most containing beneficial microbial communities capable of promoting plant growth or increasing disease resistance. Types and abundance of the dominant microbes affected network stability, potentially resulting in functional changes in different ecological niches. This study provides theoretical evidence for microbial protection of plants against diseases and demonstrates that systematic analysis of the composition and diversity of soybean microbiomes can contribute to the development of biological control technologies.

Exploring the impacts of steroid estrogens load and aeration intensity on the performance, membrane fouling characteristics, and bacterial community structure of the anoxic-oxic membrane bioreactor

Steroid estrogens (SEs) are typical endocrine-disrupting compounds, and they are inadequately eliminated in most wastewater treatment plants (WWTPs), contributing significantly to their environmental prevalence. In an effort to optimize the performance of membrane bioreactor (MBR) in mitigating SEs alike micropollutants, this study investigated the influences of influent loads of three typical SEs (estrone (E1), 17β-estradiol (E2), and 17α-ethynyestradiol (EE2)) and the aeration intensity on the pollutants removal performance, membrane fouling characteristics, and bacterial community structure in a lab-scale anoxic/oxic-MBR (A/O-MBR) process. The presence of SEs shed minimal impacts on the performance of A/O-MBR process as indicated by conventional water quality parameters due to gradual microbial acclimation. However, the presence and the rising input of SEs accelerated membrane fouling as a result of the enhanced EPS excretion and PN/PS ratio and the reduced floc size. The moderate aeration intensity was preferred from the perspectives of conventional pollutants removal, SEs biodegradation, biomass accumulation, and membrane fouling mitigation. Evolution of bacterial community structure and predominant genera were identified at different SEs loads and aeration intensities, with Candidatus Competibacter and Ferruginibacter detected as the predominant genera at different SEs input loads and Thiothrix, Azospira, and Saprospiraceae_norank at different aeration intensities with identical SEs input. The results demonstrated the potential of A/O-MBR as a promising barrier against SEs alike micropollutants through the regulation and control of aeration intensity.

Quorum sensing orchestrates parallel cell death pathways in Vibrio cholerae via Type 6 secretion dependent and independent mechanisms.

Cell death is a fundamental biological process. In mammals, cell death sculpts tissues during development, enables injury recovery, and regulates immunity. In bacteria, cell death mechanisms remain little explored. Recently, colonies formed by the pathogen Vibrio cholerae were demonstrated to undergo a spatio-temporal program of cell death. The program is controlled by quorum sensing (QS) and driven by the Type VI secretion system. Here, we discover QS-controlled genes, called vca0646-0649 , that cause cell death in V. cholerae colonies independently of the Type VI secretion system. These findings indicate that a second cell death pathway exists in V. cholerae . The results expand our understanding of bacterial cell death mechanisms and provide insight into how cell death shapes bacterial community structure.

Oat/Soybean Intercropping Reshape the Soil Bacterial Community for Enhanced Nutrient Cycling

ABSTRACTIntercropping, particularly within legume‐based systems, has been shown to enhance yields and optimize resource use efficiency. Yet, the potential contribution of intercropping on soil microbial communities and functions to soil nutrients cycling are not fully understood. We conducted the same field experiments at Youyu (Site1) and Zhangbei (Site2) in Northern China to evaluate the impact of oat/soybean intercropping on the rhizosphere soil bacterial community structure, composition, and co‐occurrence networks. Our results indicated that intercropping significantly modified the bacterial community structure for both oat and soybean at Site1, with changes observed only in the oat community at Site2. Specifically, intercropping led to a substantial increase in the relative abundance of Bacteroidetes and Patescibacteria in the oat rhizosphere by 48.3% and 65.4% (Site1), respectively. Conversely, in the soybean rhizosphere at Site1, there was a notable decrease in the abundance of Patescibacteria and Nitrospirae by 32.4% and 40.0%, respectively. The soil bacterial functional groups demonstrated robust positive correlations with key soil parameters such as available nitrogen (Nmin), available phosphorus (Avail‐P), and the activities of nitrogen‐ and phosphorus‐acquiring enzymes in the rhizosphere. In conclusion, intercropping is an effective agricultural practice for enhancing nitrogen and phosphorus cycling by reshaping the soil bacterial community, offering a distinct advantage over monoculture practices. This insight underscores the potential of intercropping to foster sustainable soil nutrient management, highlighting the importance of integrating such practices into modern agricultural strategies to ensure long‐term productivity and environmental sustainability.

Combined Effects of Nitrogen Addition and Warming on Shrub Growth and Nutrient Uptake through Microbially Mediated Soil Fertility

Plant restoration strategies are ubiquitously employed for the purposes of soil and water conservation and ecological improvement in forest ecosystems. Despite N and temperature being acknowledged as pivotal factors affecting plant restoration outcomes, their effects on soil fertility, microbial communities, and shrub biomass remain underexplored, particularly in the loess hilly regions of China. Here, we examined the growth patterns and nutrient acquisition abilities of three shrub species, Periploca sepium, Amorpha fruticosa, and Vitex negundo, along with the attendant alterations in soil properties and microbial community composition under controlled greenhouse conditions. Specifically, we imposed three levels of N fertilization (200, 400, and 600 kg ha−1; designated as N1, N2, and N3, respectively) and temperature regimes (18–23, 25–30, and 32–37 °C; labeled T1, T2, and T3, respectively). The results indicated a significant interplay between the combination of N fertilization and temperature significantly affecting shrub growth. Optimal growth conditions, as evidenced by the highest dry biomass accumulation, were identified as N3T1 for A. fruticosa, N1T1 for P. sepium, and N2T2 for V. negundo, with these conditions differentially influencing roots, stems, and leaves. Furthermore, soil microorganisms also responded significantly to the N fertilization and temperature. However, this was largely dependent on shrub species and soil nutrients. For A. fruticosa under N3T1 conditions, Actinobacteria and Basidiomycota abundances correlated strongly with soil C, N, and P contents, while leaf N uptake significantly correlated with the structure of both bacterial and fungal communities. For P. sepium at N1T1, Acidobacteriota was dominant in response to soil N and C, while leaf C uptake and leaf and stem N uptake positively correlated with bacterial and fungal communities, respectively. For V. negundo at N2T2, Chloroflexi had the greatest abundance, responding to the greatest variation in soil N and C, while its stem N uptake was significantly related to the structure of the fungal communities. Thus, our findings underscored the intricate interplay between abiotic factors, shrub growth, soil fertility, and microbial community dynamics, providing insights into the optimization of plant restoration efforts in ecologically sensitive regions.

Microbial Community Structure and Metabolic Function in the Venom Glands of the Predatory Stink Bug, Picromerus lewisi (Hemiptera: Pentatomidae).

The predatory stink bug, Picromerus lewisi (Hemiptera: Pentatomidae), is an important and valuable natural enemy of insect pests in their ecosystems. While insects are known to harbor symbiotic microorganisms, and these microbial symbionts play a crucial role in various aspects of the host's biology, there is a paucity of knowledge regarding the microbiota present in the venom glands of P. lewisi. This study investigated the venom glands of adult bugs using both traditional in vitro isolation and cultural methods, as well as Illumina high-throughput sequencing technology. Additionally, the carbon metabolism of the venom gland's microorganisms was analyzed using Biolog ECO metabolic phenotyping technology. The results showed 10 different culturable bacteria where the dominant ones were Enterococcus spp. and Lactococcus lactis. With high-throughput sequencing, the main bacterial phyla in the microbial community of the venom glands of P. lewisi were Proteobacteria (78.1%) and Firmicutes (20.3%), with the dominant bacterial genera being Wolbachia, Enterococcus, Serratia, and Lactococcus. At the fungal community level, Ascomycota accounted for the largest proportion (64.1%), followed by Basidiomycota (27.6%), with Vishniacozyma, Cladosporium, Papiliotrema, Penicillium, Fusarium, and Aspergillus as the most highly represented fungal genera. The bacterial and fungal community structure of the venom glands of P. lewisi exhibited high species richness and diversity, along with a strong metabolism of 22 carbon sources. Functional prediction indicated that the primary dominant function of P. lewisi venom-gland bacteria was metabolism. The dominant eco-functional groups of the fungal community included undefined saprotroph, fungal parasite-undefined saprotroph, unassigned, endophyte-plant pathogen, plant pathogen-soil saprotroph-wood saprotroph, animal pathogen-endophyte-plant pathogen-wood saprotroph, plant pathogen, and animal pathogen-endophyte-epiphyte-plant pathogen-undefined saprotroph. These results provide a comprehensive characterization of the venom-gland microbiota of P. lewisi and demonstrate the stability (over one week) of the microbial community within the venom glands. This study represents the first report on the characterization of microbial composition from the venom glands of captive-reared P. lewisi individuals. The insights gained from this study are invaluable for future investigations into P. lewisi's development and the possible interactions between P. lewisi's microbiota and some Lepidopteran pests.

Ecology of Airborne Microorganisms: Understanding the Impact of Haze and Sandstorms on Bacterial Community Structure and Pathogenicity

Ecology of Airborne Microorganisms: Understanding the Impact of Haze and Sandstorms on Bacterial Community Structure and Pathogenicity

Fecal microbiome and functional prediction profiles of horses with and without crib-biting behavior: A comparative study

Crib-biting is a stereotyped oral behavior with poorly understood etiology and pathophysiology. The relationship between the gut microbiome and brain function has been described in behavioral disorders such as schizophrenia, depression and anxiety in humans. In horses, studies of behavioral problems and the microbiome are very limited. This study aimed to characterize the fecal microbiome and the predicted functional profile of horses with and without aerophagia. Fecal samples were collected from 12 Colombian Creole Horses of both sexes, divided into two groups: group 1, composed of six horses with crib-biting (3 females and 3 males), average body weight of 330 ± 10 kg, age of 7.0 ± 1.2 years and body condition score (BCS) of 5/9 ± 1 and group 2, consisting of six horses without crib-biting (3 females and 3 males), average body weight of 335 ± 5 kg, age 6.5 ± 1 years and BCS of 6/9 ± 1. From each horse in both groups fecal total DNA was obtained and 16S ribosomal RNA gene amplicons were sequenced to characterize the bacterial community structure. Community structure and differential abundance analyses revealed significant differences between the two conditions (p < 0.05). Specifically, the fecal microbiota at the family level in crib-biting horses, showing a decrease in Bacteroidales and an increase in Bacillota and Clostridia, differed from that of healthy horses without crib-biting, consistent with findings from previous studies. Furthermore, metagenome prediction suggests metabolic profile changes in bacterial communities between both conditions in horses. Further studies are required to validate the role of the microbiota-gut-brain axis in the etiology of crib-biting and other abnormal and stereotyped behaviors.

Conversion to Greenhouse Cultivation from Continuous Corn Production Decreases Soil Bacterial Diversity and Alters Community Structure

Changes in crop types and long-term monoculture substantially impact soil microbial communities. Exploring these changes and their influencing factors is of great significance for addressing the challenges posed by continuous cropping. Soil surface layer samples from greenhouse tomatoes fields cultivated for 5 (Y5), 9 (Y9), 13 years (Y13), and a surrounding corn field (CK) as a control were analyzed. The Y13 sample showed a significant increase in the relative abundance of Pseudomonadota (43.1%) and a decrease in Actinobacteria (50.3%) compared to the CK sample. Soil bacterial alpha diversity generally declined from the CK to Y13 (0.1–22.2%) sample, with a small peak in Y9 for Chao1 and Observed_species. Significant differences in Chao1 and Observed_ species were observed between the CK and Y13 samples. Beta diversity analysis revealed a pronounced variation in soil bacterial community structure across planting years, with the divergence from the CK sample intensifying over time. In comparison to the Y5 vs. CK samples, Y9 and Y13 exhibited marked differences from the CK across the same and broader metabolic pathways, suggesting a potential convergence of microbial activities over time. The Y9 and Y13 samples showed significantly higher biosynthesis abundance (7.50% and 6.36%, respectively) than the CK. In terms of soil physicochemical indices, the carbon–nitrogen ratio was the primary factor influencing soil bacterial composition. In conclusion, we found that crop alteration and continued planting changed the soil’s bacterial composition and increasing planting years suppressed the soil’s bacterial diversity, leading to a stable bacterial ecology after nine years. Implementing appropriate measures during this critical period is vital for optimal soil utilization.

Temporal changes in the mouse gut bacteriota influenced by host sex, diet, and exercise.

The gut microbiota plays an important role in host physiology. However, the effects of host sex, lifestyle, and temporal influences on the bacterial community within the gut remain ill-defined. To address this gap, we evaluated 56 male and female mice over a 10-wk study to assess the effects of sex, diet, and exercise on gut community dynamics. Mice were randomly assigned to high-fat or control diet feeding and had free access to running wheels or remained sedentary throughout the study period. The fecal bacterial community was characterized by rRNA operon profiling via nanopore sequencing. Differential abundance testing indicated that ∼200 bacterial taxa were significantly influenced by sex, diet, or exercise (4.2% of total community), which also changed over time (82 taxa, 1.7% of total community). Phylogenetic analysis of taxa closely related to Dysosmobacter welbionis, and several members of the family Muribaculaceae were examined more closely and demonstrated distinct species/strain level subclustering by host sex, diet, and exercise. Collectively, these data suggest that sex and lifestyle can alter the gut bacteriota at the species/strain level that may play a role in host health. These results also highlight the need for improved characterization methods to survey microbial communities at finer taxonomic resolution.NEW & NOTEWORTHY This study demonstrates that host sex, diet, and exercise can each modulate gut bacterial community structure, which may have consequences to host physiology. Our analysis shows selection of novel strains and genera for some members of the Oscillospiraceae and Muribaculaceae by host sex, diet, and activity status. Overall, these findings provide a framework for detecting the next generation of beneficial bacteria targeting obesity and associated metabolic diseases in a sex-specific manner.