Shannon Index Research Articles

Enhancing the Growth of Chili Plants and Soil Health: Synergistic Effects of Coconut Shell Biochar and Bacillus Sp. Strain Ya-1 on Rhizosphere Microecology and Plant Metabolism

To mitigate soil degradation and decrease dependency on chemical inputs in agriculture, this study examined the joint effects of coconut shell biochar and Bacillus strain Ya-1 on soil fertility, rhizosphere bacterial communities, and the growth of chili (Capsicum annuum L.). A controlled pot experiment with four treatments was conducted: control (CK), biochar only (C), Bacillus strain Ya-1 only (B), and a combination of both (BC). The BC treatment significantly enhanced the soil carbon and available phosphorus contents by approximately 20% and the soil nitrogen content and pH by 18% and 0.3 units, respectively, compared to the control. It also increased microbial biomass carbon and nitrogen by 25% and 30%, respectively, indicating improved soil microbial diversity as shown by the highest Pielou evenness index and Shannon index values. The combined application of biochar and the Ya-1 strain resulted in a 15% increase in chili plant height and a 40% improvement in root dehydrogenase activity, suggesting enhanced nutrient uptake and metabolism. Metabolic profiling showed shifts in stress response and nutrient assimilation under different treatments. Collectively, these results indicate the potential of biochar and microbial inoculants to significantly promote soil and plant health, providing a sustainable strategy to improve agricultural productivity and reduce reliance on chemical inputs.

Thiophanate-methyl and its major metabolite carbendazim weaken rhizobacteria-mediated defense responses in cucumbers against Fusarium wilt

AbstractThe effect of fungicides on the plant-rhizosphere microbiome is a subject of ongoing debate, but whether any alteration in the rhizosphere microbiome could affect plant health is an issue that has not been thoroughly investigated. To address this deficiency, we analyzed the rhizosphere microbiome of wilt disease—resistant and disease-susceptible cucumber cultivars to determine whether (and which) plant-associated microorganisms have a role in disease resistance. We further assessed whether the fungicides thiophanate-methyl and carbendazim affect the rhizosphere microbiome, which may contribute to the plant’s immune response. Based on results acquired with both radicle-inoculation and soil-inoculation methods, cultivars Longyuanxiuchun (LYXC) and Shuyan2 (SY2) were identified as being disease resistant, whereas Zhongnong6 (ZN6) and Zhongnong38 (ZN38) were susceptible. The microbiome structure differed substantially between the resistant and susceptible plants, with LYXC and SY2 each having a significantly greater Shannon index than Zhongnong38. These results revealed that the disease-resistant cucumber cultivars recruited more beneficial bacteria, i.e., Bacillus, in their rhizosphere soil; as such, Bacillus was identified as a keystone genus in the microbial co-occurrence network. Thus, the presence of Bacillus may help cucumbers defend against fungal pathogens within the rhizosphere. Bacillus subtilis strain LD15, which was isolated from LYXC rhizosphere soil, could suppress pathogen growth, in vitro, and reduce disease severity in pot assays. Moreover, evidence also confirmed the accumulation of LD1 in the rhizosphere soil of resistant cucumber cultivars. For LYXC, application of thiophanate-methyl or carbendazim altered the microbiome structure, decreased bacterial diversity, and reduced the abundance of Bacillus species. Finally, pot assays verified that fungicide application decreased the proportion of LD15 in rhizosphere soil. From a microbial perspective, thiophanate-methyl and carbendazim may weaken the rhizobacteria-mediated defense response of cucumbers against cucumber Fusarium wilt disease. Our findings reveal a role for the rhizosphere microbiome in protecting plants from pathogens and constitute a reference for assessing the ecotoxicological risk of pesticides to non-target soil microorganisms.

Impact of green space patterns on PM2.5 levels: A local climate zone perspective

Green spaces have been demonstrated to significantly decrease PM2.5 levels. However, the impact of green spaces on PM2.5 levels in different spatial forms of urban blocks is not yet fully understood. This research utilized ensemble machine learning algorithms to investigate the impact of green space spatial patterns, assessed through landscape pattern analysis, to PM2.5 concentrations during summer and winter based on local climate zones (LCZ). The results revealed significant differences in PM2.5 concentration across the seven types of primary LCZs, primarily influenced by meteorological factors. In winter, eight green space indicators exhibited a more substantial contribution to PM2.5 levels in comparison to the summer season. Significant discrepancies were noted in the contributions of these indicators across different LCZs. Patch density (PD) and landscape shape index (LSI) made a more substantial contribution, while relative patch richness (RPR) and Shannon's evenness index (SHEI) showed a less significant contribution. The spatial pattern of green spaces was significantly related to their contributions. Among the seven predominant LCZs, the five key indicators included PD, LSI, Shannon's diversity index (SHDI), area-weighted mean patch area (AREA_AM), and connectance index (CONNECT). Spatial heterogeneity was further observed in the positive and negative contributions of each green space indicator. This study enhances understanding of the impact of green spaces on PM2.5 across LCZs and provides valuable insights for urban management and planning.

Women’s Presence on Boards and Financial Performance: Evidence from Southeast Asia

The purpose of this article is to assess the impact of female board representation on financial performance in Southeast Asia. To compare the presence of women, three proxies are used: the percentage of women, the Blau Index, and the Shannon Index. The samples for five-year intervals (2017-2021) include 249 Southeast Asian enterprises and 1,245 observations. The Fixed Effect Model results show that, based on all three proxies, women's board participation leads to lower financial performance, which contradicts the Agency and Resource Dependence Theories. This document serves as a resource for regulators and stakeholders in developing effective and proper corporate governance, particularly in board compositions that need a proportion of women in Southeast Asia. The conclusions of this study may be impacted.

Using UAV RGB Images for Assessing Tree Species Diversity in Elevation Gradient of Zao Mountains

Vegetation biodiversity in mountainous regions is controlled by altitudinal gradients and their corresponding microclimate. Higher temperatures, shorter snow cover periods, and high variability in the precipitation regime might lead to changes in vegetation distribution in mountains all over the world. In this study, we evaluate vegetation distribution along an altitudinal gradient (1334–1667 m.a.s.l.) in the Zao Mountains, northeastern Japan, by means of alpha diversity indices, including species richness, the Shannon index, and the Simpson index. In order to assess vegetation species and their characteristics along the mountain slope selected, fourteen 50 m × 50 m plots were selected at different altitudes and scanned with RGB cameras attached to Unmanned Aerial Vehicles (UAVs). Image analysis revealed the presence of 12 dominant tree and shrub species of which the number of individuals and heights were validated with fieldwork ground truth data. The results showed a significant variability in species richness along the altitudinal gradient. Species richness ranged from 7 to 11 out of a total of 12 species. Notably, species such as Fagus crenata, despite their low individual numbers, dominated the canopy area. In contrast, shrub species like Quercus crispula and Acer tschonoskii had high individual numbers but covered smaller canopy areas. Tree height correlated well with canopy areas, both representing tree size, which has a strong relationship with species diversity indices. Species such as F. crenata, Q. crispula, Cornus controversa, and others have an established range of altitudinal distribution. At high altitudes (1524–1653 m), the average shrubs’ height is less than 4 m, and the presence of Abies mariesii is negligible because of high mortality rates caused by a severe bark beetle attack. These results highlight the complex interactions between species abundance, canopy area, and altitude, providing valuable insights into vegetation distribution in mountainous regions. However, species diversity indices vary slightly and show some unusually low values without a clear pattern. Overall, these indices are higher at lower altitudes, peak at mid-elevations, and decrease at higher elevations in the study area. Vegetation diversity indices did not show a clear downward trend with altitude but depicted a vegetation composition at different altitudes as controlled by their surrounding environment. Finally, UAVs showed their significant potential for conducting large-scale vegetation surveys reliably and in a short time, with low costs and low manpower.

Effect of xylo-oligosaccharides on intestinal bacterial diversity in mice with spleen deficiency constipation.

To explore the effect of xylo-oligosaccharides on intestinal bacterial diversity in mice with spleen deficiency constipation. The 16S rDNA sequencing was used to identify microbiota composition in four groups, including the normal group (NG), the model group with spleen-deficiency constipation (SDC), XOS treated groups that include XOS1 groups treated XOS 0.05 g/mL•d, and XOS2 group treated XOS 0.1 g/mL•d. Chao1 and Shannon were used to conduct gut microbes diversity analysis. Linear discriminant analysis coupled with effect size measurements (LEfSe) was used to identify signature gut microbiota, and phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) was used to predict the function of altered gut microbiota. Veen map indicated 245 common OTUs were identified from four groups. Especially, 9, 3, 0, and 19 unique OTUs were identified in NG, SDC, XOS1, and XOS2 groups, respectively. The Shannon index was evidently higher in NG group than in the other three groups (p < 0.05). We identified the occurrence of dominant bacterial groups including Bacteroidetes (25.5 ~ 49.9%), Firmicutes (25.4 ~ 39.3%), Proteobacteria (12.5 ~ 24.9%), Deferribacteres (1.6 ~ 19.2%), Cyanobacteria (0.3 ~ 1.8%), Verrucomicrobia (0.02 ~ 1.6%), Actinobacteria (0.01 ~ 0.5%), and Tenericutes (0.03 ~ 0.09%) at the four groups. The XOS2 group was characterized by a higher abundance of Peptostreptococcaceae, Intestinibacter, Aerococcaceae, and Facklamia. XOS1 group enriched in Deferribacteres, Mucispirillum, Deferribacterales, Deferribacteres, Lachnoclostridium, Rhodospirillaceae, and Rhodospirillales. Meanwhile, the SDC mice showed dramatic enrichment in Rikenellaceae, Lachnospiraceae, Rikenellaceae, Roseburia, and Alistipes, which were highly abundant in the NG group. XOS fed-mice evidently increase Deferribcteres abundance compared with NG and SDC groups. However, the abundance of Rikenellaceae was significantly reduced in XOS1 and XOS2 groups compared with NG and SDC groups. We identified that altered gut microbiotas by XOS treatment were associated with various metabolic pathways, including organismal systems, metabolism, human diseases, genetic information processing, and cellular processes. Our research indicated that XOS has the potential to recover intestinal bacteria and contribute to the treatment of spleen deficiency constipation.

A gut-focused perinatal dietary intervention is associated with lower alpha diversity of the infant gut microbiota: results from a randomised controlled trial

ABSTRACT Objectives: In experimental models, the prenatal diet influences gut microbiota composition in mothers and offspring; however, it is unclear whether this occurs in humans. We investigated the effects of a gut-focused perinatal dietary intervention on maternal and infant gut microbiota composition four weeks after birth. Methods: This randomised controlled trial randomised pregnant women to receive dietary advice as part of standard care, or additionally receive a dietary intervention focused on the Australian Dietary Guidelines and increasing prebiotic and probiotic/fermented food intakes (ACTRN12616000936426). Study assessments occurred from gestation week 26 (baseline) to four weeks postpartum (follow-up). Faecal samples, collected at baseline for mothers, and follow-up for mothers and infants, underwent 16SrRNA sequencing. The primary outcome was a between-group mean difference in infant faecal Shannon index. Secondary outcomes included between-group differences in other microbiota measures, including maternal change from baseline CLR-transformed Prevotella abundance. Results: Forty-four women and 45 infants completed the study. The mean Shannon index of infants in the intervention group was −0.35 (95% CI: −0.64, −0.06, SD: 0.52) units lower than control group infants, corresponding to a medium effect size (Cohen’s D: −0.74, 95% CI: −1.34, −0.13). The findings were similar using other metrics of α-diversity. There were no between-group differences in β-diversity, nor any differentially abundant taxa in infants. The intervention increased abundances of the genus Prevotella in mothers compared to controls. Discussion: This gut-focused perinatal dietary intervention was associated with differences in the maternal and infant gut microbiota composition. Larger studies are required to replicate and extend these findings.

The Effects of Spatial Structure and Development Intensity of the Urban Landscape on Bird Biodiversity in Anhui Province

Exploring the factors that drive changes in biodiversity is a hot and critically important topic in landscape ecology and biogeography. In this study, semi-structured citizen science data and bird distribution maps were employed to gather data from 2015 to 2020 for the calculation of bird species richness, the Shannon index, and the Pielou index in Anhui Province. These metrics were utilized to assess avian biodiversity and to elucidate the spatial patterns of biodiversity distribution across the region. In this research, a structural equation model (SEM) was utilized to investigate the relationships between the three dimensions of landscape spatial structure, urban development intensity, and environmental factors on bird biodiversity, and a conceptual framework was established to identify the key driving factors. The validity, reliability, and fit of the hypothesized model were substantiated through rigorous testing, demonstrating its reasonableness. The results indicate the following: (1) In landscape spatial structure, landscape composition and configuration play crucial roles in influencing bird diversity. An increased proportion of cultivated land negatively impacts bird diversity, whereas the expansion of forested areas promotes it. At the configuration level, the Largest Patch Index (LPI) significantly enhances bird diversity, serving as the primary driving force. Landscape spatial structure affects bird diversity both directly, through its composition, and indirectly, through its configuration. (2) The dimension of urban development intensity generally shows significant negative impacts; among these, GDP has the greatest comprehensive impact and shows a significant negative impact. (3) Topography has the greatest overall impact on bird diversity among the environmental factors, with a predominantly direct positive effect. (4) Overall, urban landscape spatial structure and urban development intensity are the main driving forces of bird diversity in Anhui Province, the greatest of which is the direct effect of the urban development intensity. These results provide an important scientific basis for landscape planning and ecological protection and provide inspiration for assessing the driving factors of animal and plant diversity in other regions.

Assessing Carbon Stocks and Ecosystem Functioning in Char (Buchanania lanzan) Forests of Central India

The present study assessment of plant community structure, carbon stock and CO2 sequestration of char (Buchanania lanzan) dominant forest sites in Central India during 2020-22. The forest vegetation was analysed using 20 quadrats (each 10 x 10 m in size for tree layers, 5 x 5 m in size for sapling layers and 1 x 1 m size for seedling layers) within the representative one-hectare plot on each site. The biomass, carbon stock, and carbon dioxide sequestration from three district (Mahasamund, Gariaband, and Kabirdham) char dominated forest sites of dry deciduous forests in Central India were estimated using the non-destructive allometric equation approach. The results revealed that the density of tree, sapling and seedling were ranged from 430-605 stems ha-1, 120-600 stems ha-1 and 28000-34500 stems ha-1, respectively. The basal area of tree and sapling layers were varied from 18.15-29.68 m2 ha-1 and 0.33-1.04 m2 ha-1, respectively. The diversity indices of tree layer viz; Shannon index, Simpson index, Evenness, species richness and beta diversity were ranged from 2.40-2.72, 0.17-0.22, 1.08-1.18, 2.26-3.11 and 5.0-6.0, respectively on different forest site in Central India. The total biomass, carbon stock and CO2 sequestration potential of tree layers were varied from 105.72-216.96 Mg ha-1, 50.22-103.06 Mg ha-1 and 184.29-378.22 Mg ha-1, respectively on char dominant various forest sites in Central India. The correlation coefficients were statistically significant performed between basal area and biomass, carbon stock and CO2 sequestration potential with R2 values of 0.988 at p&lt;0.01 levels. After doing this study, it can be concluded that estimating the biomass and carbon stock in Central India will be useful for managing forests sustainably.

Distinct bacterial and eukaryotic communities reflect the specificity of different coral reefs in the South China Sea

The microbial composition of surrounding waters is crucial for the health of coral reefs and holds significant value for understanding the complexity and environmental adaptability of coral reef ecosystems. This study reveals the spatial heterogeneity and diversity characteristics of bacterial and eukaryotic communities in different coral reef regions of the South China Sea. Chao and Shannon indices showed significant differences (p < 0.05) in diversity of bacterial and eukaryotic communities across different coral reefs. PCoA (principal coordinate analysis) indicates significant differences in community composition among regions, highlighting the crucial role of coral reef environmental heterogeneity on microbial community. NST (normalized stochasticity ratio) analysis indicates that community assembly in coral reef areas is more influenced by ecological stochastic processes. Major bacterial groups include Proteobacteria, Cyanobacteria, and Bacteroidota, while dominant eukaryotic groups include Dinophyceae, Apicomplexa, Bacillariophyta, Florideophyceae, Mamiellophyceae, Syndiniales, Prasino-Clade-VII, and Ascomycota, each showing significant abundance differences across coral reef regions (p < 0.05). High abundance of Rhodobacterales and Flavobacteriales are detected in all coral reef waters. Correlation analysis indicates that temperature, pH, and salinity are important factors affecting the bacterial and eukaryotic communities. This study reveals the spatial heterogeneity of microbial communities in coral reef regions of South China Sea and underscores the significant impact of marine environmental heterogeneity on community structure.

The Addition of Hot Water Extract of Juncao-Substrate Ganoderma lucidum Residue to Diets Enhances Growth Performance, Immune Function, and Intestinal Health in Broilers.

The purpose of this experiment was to investigate the effects of Hot Water Extract of Juncao-substrate Ganoderma lucidum Residue (HWE-JGLR) on the immune function and intestinal health of yellow-feather broilers. In an animal feeding experiment, 288 male yellow-feather broilers (1 day old) were randomly allocated to four treatment groups with six replicates of 12 birds each. The control (CON) group was fed a basal diet. HJ-1, HJ-2, and HJ-3 were fed a basal diet supplemented with 0.25%, 0.50%, and 1.00% HWE-JGLR, respectively. The feeding trial lasted for 63 d. The results showed increased ADFI (p = 0.033) and ADG (p = 0.045) of broilers in HJ-3, compared with the CON group. Moreover, higher contents of serum IL-4 and IL-10 and gene expression of IL-4 and IL-10 in jejunum mucosa and lower contents of serum IL-1β and gene expression of IL-1β in jejunum mucosa in HJ-3 were observed (p < 0.05). Additionally, the jejunal mucosal gene expression of Claudin-1 and ZO-1 in HJ-2 and HJ-3 was higher than that in the CON group (p < 0.05). As for the microbial community, compared with the CON group, the ACE index, Shannon index, and Shannoneven index of cecal microorganisms in HJ-2 and HJ-3 were elevated (p < 0.05). PCoA analysis showed that the cecal microbial structure of broilers in HJ-2 and HJ-3 was different from the CON group (p < 0.05). In contrast with the CON group, the broilers in HJ-2 and HJ-3 possessed more abundant Desulfobacterota at the phylum level and unclassified Lachnospiraceae, norank Clostridia vadinBB60 group and Blautia spp. at the genus level, while Turicibacter spp. and Romboutsia spp. were less (p < 0.05). In conclusion, dietary supplementation with HWE-JGLR can improve growth performance, enhance body immunity and intestinal development, and maintain the cecum microflora balance of yellow-feather broilers.

Microbial diversity in primary endodontic infections: demographics and radiographic characteristics.

To analyze if the microbiome community composition in primary endodontic infections is associated with clinical or radiographic factors. Seventy-one patients with primary endodontic infections were evaluated for percussion tenderness, presence of a sinus tract, presence of caries, sex, probing depth > 4mm, and age. Samples from the root canals were obtained and the microbiome was subsequently characterized by 16S rRNA amplicon sequencing. For the radiographic analysis, a subset of 12 samples with a periapical index (PAI) ≤ 2 were compared with 19 samples with PAI of 5. The Shannon and Chao1 indices were used to measure alpha diversity. Differences in abundances of genera were evaluated using the Kruskal-Wallis test with Bonferroni's correction. Differences in community composition were evaluated using analysis of similarity (ANOSIM) with Bray-Curtis dissimilarity matrices. No significant differences in microbiome composition relative to clinical factors were found using ANOSIM. Teeth within the two categories of periapical index showed a similar number of species richness, and alpha diversity values P > 0.05. Community composition was significantly affected by the periapical index (ANOSIM P = 0.039, R = 0.10). Larger radiographic lesions demonstrated significant increase in Prevotellaceae, Olsenella, and the motile bacteria Oribacterium, Selenomonadaceae spp., and Treponema. Clinical factors associated with apical periodontitis have a limited impact on the root canal microbiome composition. Community composition appears to be affected in teeth with large apical lesions.

Spiders (Araneae) from square samples and pitfall traps in coastal heathland, western Norway. Habitat preference, phenology and distribution

Square samples were taken at intervals of 3 - 4 weeks (early spring 1972 - late summer 1973) in a heterogenous plant association dominated by Calluna vulgaris and several moss species (Loc.I), and in a homogenous, humid Sphagnum mat (Loc.II) with very sparse Calluna. Probably due to an unusually dry spring/early summer in 1972 the density of spiders decreased drastically towards mid-summer at Loc.I, especially the linyphiids and in particular their juveniles (less so at Loc.II). During late autumn/early winter a maximum of approximately 300 and 200 specimens per square meter was reached at Loc I and II, respectively. A total of 43 species were found; at Loc.I 42 species and at Loc. II 29 species. The Shannon indices of general diversity were 2.28 and 1.26, respectively. The sharing of 28 species gave a fairly high Soerensen index of similarity (0.79) but a rather low Renkonen index (0.30). At Loc.I the four most dominant species (range 12 - 21% ), Minyriolus pusillus, Erigonella hiemalis, Gongylidiellum latebricola and G. vivum, represented 59% of the total. At Loc.II the two most dominant species Robertus arundineti (45%) and Minyriolus pusillus (10%) represented 55% of the total. Pitfall traps emptied every 3 - 4 weeks added another 25 species to the list, including some abundant lycosids, and occasional sampling elsewhere in the area added 6 species. Phenological data are presented, and for some abundant species briefly discussed with notes on their habitat preferences and distribution.

Epigaeic spiders (Araneae) from three habitats at Stryn, Nordfjord, Western Norway

One year of pitfall sampling in (A) a narrow strip of vegetation (junipers, Rosa sp., small pines) close to a river bank, (B) a cultivated medium humid meadow and (C) a humid deciduous forest (Alnus) with some grass on the ground collected a total of 25, 48 and 32 species, respectively (in total 67 species). Shannon indices of general diversity (ln e) were 1.8, 2.1 and 3.1, respectively. The three sites shared only 9 species, 57% of all species were found in only one locality. Similarity indices were low, especially between loc. A and C. Linyphiidae and Lycosidae were dominant. The latter were scarce in loc. B and C but common at loc. A (Pardosa palustris and P. amentata together comprising 43.5% of total) and net building species more scarce. The local distribution, co-existence, ecological and habitat preferences, seasonal activity and body size of some common species are briefly discussed. For some species, aspects of geographical distribution are discussed.

The Mycobiota of Library Books in Russia.

Abstract-Numerous studies of microorganisms isolated from the surface of cultural heritage objects, including library documents, are regularly carried out in different countries. Although the micromycete composition in each case varies, some species are constantly isolated. The structure of micromycete communities that inhabit library documents was studied in 57 cities of Russia located in seven federal districts (Northwestern, Central, Southern, Volga, Ural, Siberian, and Far Eastern). Micromycetes of 95 species from 32 genera were isolated and identified. The mycobiota of the library documents represented by Ascomycota has more than 90% of the species richness; Mucoromycota make up 3-9% and Basidiomycota, 3-4%. The Aspergillaceae family was the leading family: it accounted for 48.5-67.3% of the total species richness. In all regions, species diversity is moderate: the Shannon index ranged from 2.7 to 3.3. The Mcintosh species richness index is high everywhere (48-126), except in the Ural district (15.3). The McIntosh (0.76-0.84) and Pielow (0.80-0.91) dominance indices indicate a high level of species evenness in the mycobiota. The obtained values demonstrate the stability the document mycobiota in libraries from different regions. Significant species similarity between the districts was revealed by calculation of binary coefficients: the Jaccard coefficient was from 0.44 to 0.60; the Sørensen's qualitative measure of similarity was from 0.63 to 0.75; the quantitative similarity measure of Sørensen was from 0.44 to 0.71, and Morisita-Horn was from 0.66 to 1.0. The groups of dominant species in different regions are quite similar. The study of the ecological diversity of mycobiota on library books demonstrated the moderate diversity and the stability of the community. A high degree of similarity of taxonomic structures was established regardless of the climate conditions of the regions. Cosmopolitans characterized by high frequency of occurrence formed the major core of the library book mycobiota: Alternaria alternata, Aspergillus niger, Cladosporium cladosporioides, Mucor plumbeus, and Penicillium aurantiogriseum.

Rhizosphere microbial community assembly as influenced by reductive soil disinfestation to resist successive cropping obstacle.

Reductive soil disinfestation (RSD), which involves creating anaerobic conditions and incorporating large amounts of organic materials into the soil, has been identified as a reliable strategy for reducing soilborne diseases in successive cropping systems. However, limited research exists on the connections between soil microorganism composition and plant diseases under various types of organic material applications. This study aimed to evaluate the effects of distinct RSD strategies (control without soil amendment; RSD with 1500 kg ha-1 molasses powder; RSD with 3000 kg ha-1 molasses powder; RSD with 3000 kg ha-1 molasses powder and 37.5-41.3 kg ha-1 microbial agent) on the plant disease index, bacterial community composition and network structure in rhizosphere soil. RSD treatments significantly reduced the occurrence of black shank disease in tobacco and increased soil bacterial diversity. High amounts of molasses powder in RSD treatments further enhanced disease inhibition and reduced fungal abundance and Shannon index. RSD also increased the relative abundance of bacterial phylum Firmicutes and fungal phylum Ascomycota, while decreasing the relative abundance of bacterial phyla Chloroflexi and Acidobacteriota and fungal phylum Basidiomycota in rhizosphere soil. A multiple regression model identified bacterial positive cohesion as the primary factor influencing the plant disease index, with a greater impact than bacterial negative cohesion and community stability. The competition among beneficial bacteria for creating a healthy rhizosphere environment is likely a key factor in the success of RSD in reducing plant disease risk. RSD, especially with higher rates of molasses powder, is a viable strategy for controlling black shank disease in tobacco and promoting soil health by fostering beneficial microbial communities. This study provides guidelines for soil management and plant disease prevention. © 2024 Society of Chemical Industry.

Dynamic perspectives on biodiversity quantification: beyond conventional metrics.

Our research addresses the pressing need to assess biodiversity in the face of increasing habitat destruction and species extinctions. Several researchers have modelled conventional measures to assess biodiversity. Every measure evaluates biodiversity by considering different properties. Among them Simpson and Shannon indices are widely used, they primarily focus on species richness and abundance, overlooking the importance of rare or unique species. This limitation makes it challenging to identify which species drive changes in biodiversity and hampers conservation efforts. Moreover, these measures are sensitive to sample size and biased towards dominant species, leading to inaccurate estimations. To overcome these challenges, we propose a novel mathematical model that provides a comprehensive assessment of biodiversity. Our model accounts for species dominance, addresses sample size sensitivity, and highlights the significance of rare species within a community. By applying our measure to real-time scenarios and comparing it with traditional methods using the same dataset, proposed measure demonstrated its efficacy in capturing biodiversity dynamics over time.

Phage communities in household-related biofilms correlate with bacterial hosts

The average American spends 93% of their time in built environments, almost 70% of that is in their place of residence. Human health and well-being are intrinsically tied to the quality of our personal environments and the microbiomes that populate them. Conversely, the built environment microbiome is seeded, formed, and re-shaped by occupant behavior, cleaning, personal hygiene and food choices, as well as geographic location and variability in infrastructure. Here, we focus on the presence of viruses in household biofilms, specifically in showerheads and on toothbrushes. Bacteriophage, viruses that infect bacteria with high host specificity, have been shown to drive microbial community structure and function through host infection and horizontal gene transfer in environmental systems. Due to the dynamic environment, with extreme temperature changes, periods of wetting/drying and exposure to hygiene/cleaning products, in addition to low biomass and transient nature of indoor microbiomes, we hypothesize that phage host infection in these unique built environments are different from environmental biofilm interactions. We approach the hypothesis using metagenomics, querying 34 toothbrush and 92 showerhead metagenomes. Representative of biofilms in the built environment, these interfaces demonstrate distinct levels of occupant interaction. We identified 22 complete, 232 high quality, and 362 medium quality viral OTUs. Viral community richness correlated with bacterial richness but not Shannon or Simpson indices. Of quality viral OTUs with sufficient coverage (614), 532 were connected with 32 bacterial families, of which only Sphingomonadaceae, Burkholderiaceae, and Caulobacteraceae are found in both toothbrushes and showerheads. Low average nucleotide identity to reference sequences and a high proportion of open reading frames annotated as hypothetical or unknown indicate that these environments harbor many novel and uncharacterized phage. The results of this study reveal the paucity of information available on bacteriophage in indoor environments and indicate a need for more virus-focused methods for DNA extraction and specific sequencing aimed at understanding viral impact on the microbiome in the built environment.

Altered Gut Microbiome Composition in Dogs with Hyperadrenocorticism: Key Bacterial Genera Analysis

Hyperadrenocorticism (HAC) is a common endocrine disorder in dogs, which is associated with diverse metabolic abnormalities. We hypothesized that elevated cortisol levels in dogs with HAC disrupt the gut microbiome (GM), and this disruption persists even after trilostane treatment. This study explored GM composition in dogs with HAC. We included 24 dogs, 15 with HAC and 9 healthy controls, and followed up with 5 dogs with HAC who received trilostane treatment. The GM analysis revealed significant compositional changes in dogs with HAC, including reduced microbiome diversity compared to healthy controls, particularly in rare taxa, as indicated by the Shannon index (p = 0.0148). Beta diversity analysis further showed a distinct clustering of microbiomes in dogs with HAC, separating them from healthy dogs (p &lt; 0.003). Specifically, an overrepresentation of Proteobacteria (Pseudomonadota), Actinobacteria, Bacteroides, Enterococcus, Corynebacterium, Escherichia, and Proteus populations occurred alongside a decreased Firmicutes (Bacillota) population. Despite trilostane treatment, gut dysbiosis persisted in dogs with HAC at a median of 41 d post treatment, suggesting its potential role in ongoing metabolic issues. We identified GM dysbiosis in dogs with HAC by examining key bacterial genera, offering insights into potential interventions like probiotics or fecal microbiota transplants for better HAC management.

Sex-Dependent Rhizosphere Microbial Dynamics and Function in Idesia polycarpa through Floral and Fruit Development

Male Idesia polycarpa, which display distinct morphological and physiological traits, exhibit greater adaptability to stressful environments than females. However, the connection between this adaptability and rhizosphere processes remains unclear. Here, we investigate the differences in root bacterial community structures between male and female plants at different developmental stages, identifying bacterial strains associated with plant sex through functional predictions. This study aims to inform the optimal allocation of male and female plants during cultivation and provide a theoretical basis for sex identification and breeding. Samples from seven-year-old male and female plants were collected during the flowering (May) and fruit ripening (October) stages. Rhizosphere nutrient content and bacterial diversity were analyzed using Illumina high-throughput sequencing technology. The results demonstrate that total nitrogen (TN), total carbon (TC), and available potassium (AK) varied between sexes at different times. No significant differences between male and female plants were observed in the Shannon, Simpson, and Chao1 indexes during the flowering period. However, the Chao1 and Shannon indexes were significantly higher at fruit maturity in male rather than female plants. The predominant phyla of rhizosphere bacteria were Pseudomonadota, Acidobacteriota, and Actinomycetes. Interestingly, from flowering to fruit ripening, the dominant phyla in both male and female plants shifted from Actinomycetes to Pseudomonadota. A significant correlation was observed between pH and AK and rhizosphere bacteria (p &lt; 0.05), with metabolism being the main functional difference. This study provides preliminary insights into the functional predictions and analyses of bacteria associated with Idesia polycarpa. The above findings lay the groundwork for further investigation into the sex-specific differences in microbial flora across different developmental stages, elucidating the mechanisms underlying flora changes and offering theoretical support for the high-quality management of Idesia polycarpa.