Simpson Index Research Articles

Influence of combined application of tetracycline and streptomycin on microbial diversity and function in rice soil.

A microcosm experiment was performed to quantify the residues of antibiotics [tetracycline (TC), streptomycin (STR), and streptocycline (STC; a mixture of TC and STR)] in rice soil and to assess their impact on microbial community structure and function using Illumina-MiSeq metagenomic analysis. Antibiotics were applied at half the recommended dose (0.5RD), recommended dose (RD), and double the recommended dose (2RD). At RD, TC was degraded in soil within 9days of its application, whereas it took 21days for STR and STC to degrade below limit of quantification (LOQ) level. The residue data were fitted in decay models, and half-lives (DT50) were 46.5-53.3h and 177.6-198h for TC and STR, respectively. Soil enzyme activities (dehydrogenase, β-glucosidase, fluorescein diacetate hydrolase, acid phosphatase, alkaline phosphatase) were negatively affected in the antibiotic-treated soil. Targeted metagenomic analysis showed that the major bacterial phyla such as Chloroflexi, Actinobacteria, Planctomycetes, Crenarchaeota, and Gemmatimonadetes were suppressed by antibiotic treatments as compared to control. Shannon, Simpson, ACE, and Chao1 diversity indices showed that bacterial diversity decreased with the application of antibiotics, and decrease in bacterial diversity was more prominent in case of STC as compared to TC and STR. Overall, the combination of antibiotics negatively affected the soil microbial community structure and function in comparison to their individual application.

Hydrogen-rich water 400ppb as a potential strategy for improving ruminant nutrition and mitigating methane emissions.

The objective of this study was to evaluate the effects of different concentrations of hydrogen-rich water (HRW) on in vitro rumen fermentation characteristics and the dynamics of bacterial communities. The experiment included four treatment groups: a control (CON) and hydrogen-rich water (HRW) at 200, 400, and 800 ppb. Each group was analyzed at 12-hour (h) and 48-hour (h) time points with five replicates, totaling 40 samples. The experimental results highlighted the HRW800ppb group as the top production in terms of gas production and CH4 content. In contrast, the HRW200ppb group exhibited significantly lower methane levels at both 12h and 48h (P < 0.05). Regarding rumen fermentation, the HRW400ppb group significantly increased the levels of ammonia nitrogen (NH3-N) and microbial crude protein (MCP) at 12h fermentation, but reduced the dry matter degradation rate (P < 0.05). After 48h, the HRW400ppb group had highest MCP content (P < 0.05), but no significant differences in NH3-N and dry matter degradation rate compared with the CON group (P > 0.05). Although HRW did not significantly benefit the synthesis of total volatile fatty acids (TVFA) and individual VFA, the HRW800ppb group significantly increased the ratio of acetate to propionate (P < 0.05). Based on CH4 emissions and MCP synthesis, we selected the HRW400ppb group for subsequent bacterial community analysis. Bacterial community analysis showed that at 12h, compared with the CON group, the Bacterial community analysis revealed that the HRW400ppb group had significant increases in the Simpson index, Firmicutes, Streptococcus, Schwartzia, Prevotellaceae_YAB2003_group, and Oribacterium, and decreases in Prevotella, Ruminobacter, Succinivibrio, unclassified_Succinivibrionaceae, and Prevotellaceae_UCG-003 (P < 0.05). At 48h, the Prevotellaceae_YAB2003_group and Oribacterium abundances continued to rise significantly, while Rikenellaceae_RC9_gut_group and Succiniclasticum abundances fell in the HRW400ppb group (P < 0.05). Correlation analysis indicated a negative link between CH4 and Streptococcus, and a positive correlation between the abundance of Rikenellaceae_RC9_gut_group and CH4. Collectively, these results indicate that HRW can modulate rumen fermentation and microbial community structure to reduce methane emissions without significantly affecting VFA synthesis, highlighting its potential as drinking water for enhancing ruminant nutrition and mitigating the environmental impact of livestock farming.

Effect of host genetics on gut microbiota composition in an italian honeybee breeding population

Honeybees host a specialised gut microbiota composed of five ever-present bacteria, which undergo seasonal variation in their proportions. The objective of this study was to investigate how host genetics can affect the microbial composition of the honeybee gut over a 5-month sampling period. Seventy-seven colonies from eight maternal genetic lines were sampled from a breeding population located in Lombardy, Italy. The colonies have been selected since 2015 for three different traits, using isolated mating stations for reproduction. Worker bees were sampled three times: June, July and October 2021. From each colony, gut from ten worker bees were pooled, and the V3-V4 region of the 16S rRNA gene was amplified and sequenced. Statistical analyses were conducted in the R environment to assess the impact of genetic lines, timepoints, and their interaction on α-diversity and β-diversity. Results for α-diversity showed a significant effect of genetic line on the Simpson index, as well as a consistent effect of the timepoint. Specifically, genetic line H showed a lower Simpson index, and this line also produced less honey in the same years, suggesting a genetic influence on both microbiota richness and honey yield. For β-diversity, results revealed that the month of sampling had the strongest effect, while no significant differences were identified for the genetic line or their interaction.

Kawí Tamiruyé: a permanent research forest plot in the Sierra Tarahumara

This study characterizes the dasometric and structural parameters of a permanent research plot in northern Mexico. From a total census, 2165 trees (n) were recorded in an area of 1.4 ha-1 and, through the application of various sampling schemes, dasometric variables, and diversity indices were estimated for comparison with the census of a reference plot. We calculated the following dasometric measurements, Quadratic Mean Diameter (QMD)= 12.16 cm, Crown Area (CA)= 61.6%, Reineke's Stand Density Index (SDI)= 668 individuals, Basal Area (BA)= 25.16 m2, Total Volume (Vol)= 158.83 m3 ha-1, aboveground biomass (AGB= 142.78 Mg ha-1) and Carbon (C= 71.39 Mg ha-1). Ecologically, the species with the highest importance value index (IVI) were P. engelmannii and J. deppeana (50.8% and 35%, respectively). The Simpson's dominance index (δ)= 0.39 and diversity (λ)= 0.61 were low, as was the Shannon-Weaver index of diversity (H'= 1.3), which is in agreement with the Margalef index (DMg= 1.04). The value of Pielou's evenness (J'= 0.53) confirmed low abundance. Equidistant systematic sampling at 40 m was closer to the reference census, presenting lower values in the mean and variance estimators compared to the other sampling methods. The results can be included in management portfolios to improve decision-making. Although further studies on site size, inclusion of additive indices, and operational costs are required.

Eco-Habitat Assessment of One of the Most Expensive Edible Mushrooms (Tricholoma matsutake) in Genekha, Thimphu, Bhutan

Tricholoma matsutake (S. Ito &amp; Imai) Singer is most expensive edible mushroom, naturally grown dispersed in temperate oak pine forested areas in Bhutan. It is ectomycorrhizal fungi with high ecological and economic value requiring an important ecological niche and symbiotic tree associates. The present study is an attempt to give an account on floristic composition and vegetation structure of Tricholoma matsutake habitat in Genekha, Thimphu. A total of 10 plots were enumerated with plot size of 20m X 20m, 5m X 5m and 2m X 2m for trees, shrubs and herbs respectively. PAST (Paleontological Statistics) 4.10 software was used for diversity analysis. A total of 58 species under 44 genera belonging to 26 families were recorded in the natural habitat of matsutake. The study revealed that T. matsutake is associated with Quercus semecarpifolia Sm., Pinus wallichiana A.B. Jack., Rhododendron spp., and Pieris formosa (Wall.) D. Don. J-shaped distribution curve of DBH and height class with fair regeneration status is obtained for associated species in the habitat. The Menhinick’s species richness of (2.26, 2) for both North facing habitat (NFH) and South facing habitats (SFH) indicated high species richness. Moderate and low diversity is indicated with Simpsons index 0.94 (NFH) and 0.76 (SFH), Shannon index 3.06 (NFH) and 2.49 (SFH) with moderately even distribution 0.74(NFH) and 0.73 (SFH) of species in the habitats. Sorensens similarity index of 0.9 indicated highly similar species composition between two habitats. This research provides current floristic and vegetation structure of Tricholoma matsutake habitat, that will have high significance in habitat management and conservation.

Investigating Microbial Diversity in the Endosphere and Rhizoplane of Three Aromatic Rice Landraces: Implications for Biological Nitrogen Fixation.

Biological nitrogen fixation (BNF) occurring in the rhizosphere is a sustainable source of nitrogen for plants. BNF in cereal crops can be promoted by inoculation of a single or consortium of associative and endophytic diazotrophs. Creating a successful nitrogen-fixing biofertilizer necessitates the study of the core microbiome of the plant rhizosphere and the functional relationship of the members. This study compares the endosphere and rhizoplane microbial diversity of three aromatic landraces and one high-yielding variety of rice using culture-independent methods. The V3-V4 variable regions of 16S rRNA were used for amplicon sequencing of soil DNA. Patescibacteria, Planctomycetota, and Proteobacteria were the predominant phyla in all four genotypes. Richness (Chao-1 and ACE) and microbial diversity indices (Shannon and Simpson indices) showed that microbial diversity among the genotypes varies subtly at the phylum level. Beta diversity analysis with the phylum identified and comparisons of the microbiome at the genus level revealed a more prominent effect of plant genotype on microbial diversity. Canonical component analysis drew a correlation between microbial diversity in each genotype with the sugar and N content of these landraces. Paraburkholderia was identified as one of the major OTUs among the known nitrogen fixing followed by Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium group, Azospirillum, Hebarspirillum, and Azotobacter.

Responses of Legume‐Associated Rhizobacterial Communities to Plant Diversity and Soil Traits in Alpine Grassland

ABSTRACTLegume species are essential components of plant diversity and affect soil biodiversity across various ecosystems. Their effect on the diversity and traits of soil bacteria, particularly in degraded grasslands, remains unknown. This study analysed the relationships among plant diversity, soil traits and legume‐associated rhizobacterial communities in Xiahe (XH) and Maqu (MQ) in Gansu Province, Haibei (HB) in Qinghai Province and Hongyuan (HY) in Sichuan Province in the eastern Qinghai‐Tibetan Plateau (QTP). The diversity index values (coverage, richness, Shannon index and evenness) of legume species were positively correlated with plant diversity. Several soil nutrients (ammonia‐nitrogen, nitrate‐nitrogen, total nitrogen, available potassium, available phosphorus and soil organic matter) and enzymes (urease, sucrase, peroxidase and dehydrogenase) were lower in HB and HY than in XH and MQ. The Shannon index for rhizobacterial diversity was higher in HB and HY than in XH and MQ. In contrast, the diversity index values were higher for geographical locations than for sympatric plant species. Additionally, HB and HY showed 50% fewer positive and negative associations with rhizobacteria than XH and MQ. Functional Annotation of Prokaryotic Taxa analysis indicated a higher relative abundance of nitrate reduction occurred in HB and HY than in XH and MQ, whereas nitrogen fixation occurred at a lower level in HB and HY than in XH and MQ. The Simpson index value for bacterial diversity was positively correlated with plant diversity, legume species diversity and soil multifunctionality. However, the Shannon index value was negatively correlated with these parameters. Changes in the composition of legume‐associated rhizobacteria across different geographical locations are strongly influenced by plant diversity and soil nutrients, reflecting the distribution characteristics of legumes in alpine grasslands.

The relationship between body size and diet breadth in non‐web building spiders

Abstract The handling hypothesis assumes that large animals have broader diets than small animals because small animals are restricted to small prey while large animals can handle both small and large prey. On the other hand, the optimal foraging hypothesis assumes no relationship between predator body size and diet breadth because large predators should shift from small prey to large prey to maximize the net energy intake. Using the diets and body sizes of 89 non‐web building spider species obtained from public databases (World Spider Trait database, Spiders of Europe and World Spider Catalogue), we investigated the relationship between body size and diet breadth in this group of terrestrial arthropod predators. We found that the taxonomic niche diet breadth measured by Hill numbers (i.e., prey richness, Shannon index of diversity and Simpson index of equitability) had no significant relationship with spider body size. The minimum prey size did not show any relationship with spider body size. On the other hand, mean, maximum, range and variability in prey size increased with spider body size. The results provide support for both hypotheses. The pattern in prey taxonomic dimension supports the optimal foraging hypothesis, while the pattern in prey size dimension supports the handling hypothesis. Overall, the observed distinct patterns between the taxonomic and prey size niche axes can be caused by the fact that the non‐web building spiders utilize similar prey types that are however highly size‐structured.

Supplementation with inulin reverses cognitive flexibility alterations and modulates the gut microbiota in high-fat-fed mice

IntroductionAlterations in cognitive performance are associated with inadequate nutritional states and diet composition. Prebiotics, such as inulin, are substances that can modulate the gut microbiome and, consequently, brain function by producing metabolites such as short-chain fatty acids (SCFAs). This study aimed to evaluate the effect of supplementation with inulin on cognitive flexibility, body composition, and gut microbiota in a murine model exposed to a high-fat (HF) diet.MethodsCD1 mice were divided into five groups: control fed a standard diet (C), high-fat diet (HF), inulin (I), high-fat diet with inulin (HFI), and manipulation control (M). Dietary supplementation was administered for 6 weeks. Cognitive flexibility was assessed using the Attentional Set-Shifting Test (AST). In addition, body composition was measured via electrical bioimpedance and adipose tissue compartments of each mouse were removed and weighed. Finally, gut microbiota metataxonomic was analyzed through metataxonomic bacterial 16S rRNA sequencing.ResultsWe observed that HF group required more AST trials than the C, HFI, and I groups in the compound discrimination (CD) and extra-dimensional (ED) stages. Notably, the HFI group required fewer trials than the HF group in the ED stage (p = 0.0187). No significant differences in overall body composition were observed between the groups. However, the percentage of gonadal and peritoneal adipose tissue was significantly higher in the HF and I groups compared to the C group. Statistically significant differences in alpha diversity for gut microbiota were observed using the Shannon, Simpson, and Chao1 indices. The I group showed a decrease in bacterial diversity compared to the HF group. While no differences were observed between groups in the phyla Bacillota and Bacteroidotes, Clostridium bacteria represented a lower proportion of sequences in the I group compared to the C group. Additionally, Lactobacillus represented a lower proportion of sequences in the HF group compared to the C and I groups.DiscussionThese findings suggest that supplementation with inulin could be a useful approach to mitigate the negative effects of an HF diet on cognitive flexibility and modulate gut microbiota composition.

Spatiotemporal diversity of bacterial endophyte microbiome of mandarin (Citrus reticulata) in the northern Persian Gulf and its HCN production and N2 fixation.

Endophytes are symbionts that live in healthy plants and potentially improve the health of plant holobionts. Here, we investigated the bacterial endophyte community of Citrus reticulata grown in the northern Persian Gulf. Bacteria were isolated seasonally from healthy trees (root, stem, bark, trunk, leaf, and crown tissues) in four regions of Hormozgan province (i.e., Ahmadi, Siyahoo, Sikhoran, Roudan), a subtropical hot region in Iran. A total of 742 strains from 17 taxa, 3 phyla, and 5 orders were found, most of which belonged to Actinobacteria (Actinobacteriales) as the dominant group, followed by Firmicutes (Bacillales), Proteobacteria (Sphingomonadales, Rhizobiales), and Cyanobacteria (Synechoccales). The genera included Altererythrobacter, Arthrobacter, Bacillus, Cellulosimicrobium, Curtobacterium, Kocuria, Kytococcus, Methylopila, Mycobacterium, Nocardioides, Okiabacterium, Paracraurococcus, and Psychrobacillus. The most frequently occurring species included Psychrobacillus psychrodurans, Kytococcus schroetri, and Bacillus cereus. In addition, the overall colonization frequency and variability of endophytes were higher on the trunks. The leaves showed the lowest species variability in all sampling periods. The frequency of endophyte colonization was also higher in summer. The Shannon-Wiener (H') and Simpson indices varied with all factors, i.e., region, season, and tissue type, with the maximum in Roudan. Furthermore, 52.9% of the strains were capable of nitrogen fixation, and 70% produced antagonistic hydrogen cyanide (HCN). Thus, C. reticulata harbors a variety of bioactive bacterial endophytes that could be beneficial for host fitness in such harsh environments.

Insights into the culturable fungal endophytes of Dioscorea bulbifera L. in terms of their diversity, antidiabetic and antioxidant activity

The research on endophytes is focused on understanding the complex microbiome compositions, their interactions with host plants and their bioactive potential. Our study provided an overview of the diversity, distribution and bioactivities of culturable endophytic fungi associated with fungal endophytes of Dioscorea bulbifera L. The phylogenetic analysis depicted the evolutionary relationship among taxa of endophytic fungal isolates. The isolated fungal endophytes belonged to twenty-five genera and thirty-eight species. Further, diversity indices demonstrated significant diversity of fungal endophytes in the different tissues: stem, leaf, tuber and bulbil. A higher consistency of endophytic fungal isolates in the bulbils was found using Shannon index. Furthermore, Simpson's index revealed that the leaf tissue harboured highly diverse fungal endophytes. Likewise, Margalef's index depicted high taxonomic richness in bulbils. The isolates such as Acrocalymma medicaginis, Curvularia lycoperscii, Talaromyces macrospora, Fusarium laceratum, Paecilomyces formosus and Microascus cirrosus isolated in this study have been reported as endophytes for the first time from any plant. In-vitro antioxidant and antidiabetic activities of the ethyl acetate extracts revealed that Nigrospora oryzae (Z2) effectively inhibited α-glucosidase activity with IC50 value of 0.6 µg/ml whereas IC50 value of the acarbose, the positive control was reported to be 0.040 µg/ml. The results of antioxidant activity demonstrated that H15A (Acrocalymma medicaginis) and BD5 (Phomopsis longicolla) could be used as potential sources of antioxidant agents. Moreover, H15A (Acrocalymma medicaginis) was reported to produce 687.1 ± 0.17 µg GAE/mg of TPC and 78.55 ± 0.29 µg QE/mg of TFC quantitatively. These findings suggest that the potential endophytes could be explored using systematic bio-guided investigations to further discover novel natural products. Our study provides an important resource for a deeper understanding of endophyte-plant interactions at molecular and genetic levels.

Effects of Cassava Pellets and Enzymes Addition on Growth Performance, Meat Quality, Serum Biochemical Indices and Cecum Microbiota of Broilers

The composition of feed significantly influences the growth performance and gut microbiota of broiler chicks, impacting their overall health and productivity. This study aimed to investigate the effects of cassava pellets and enzymes supplementation on the growth performance, meat quality, serum biochemical indices, and cecal microbial community of broiler chicks. A total of 144 healthy 1-day-old AA broilers were randomly assigned to six dietary groups: basal diet (K1), basal diet + 5% cassava pellets (K2), basal diet + 10% cassava pellets (K3), basal diet + 20% cassava pellets (K4), basal diet + 20% cassava pellets + 0.3% tannase (K5), and basal diet + 20% cassava pellets + 0.3% tannase + 2500 U/kg α-amylase (K6). At 21 days, growth performance, meat quality, serum biochemical indices, and cecal microbial composition were analyzed. Compared to K1, the end weight was significantly higher in the K3 and K5 groups (P < 0.05); average daily weight gain was significantly higher in the K3 and K6 groups (P < 0.05); and the feed-to-weight ratio was lower in the K3 group (P < 0.05). Cecal microbiota analysis revealed that the Bacteroidetes, Firmicutes, and Proteobacteria were the dominant phyla. Alpha diversity showed a significant increase in the Chao index in the K3 group and in the Shannon and Simpson indices in the K6 group compared to the K1 group (P < 0.05). Beta diversity indicated similar microbial compositions across groups. LEfSe analysis showed increased numbers of specific bacteria in treated groups. Serum analysis revealed significantly higher ALT levels in the K4 group and higher IBIL levels in the K5 group (P < 0.05), with Bacteroides plebeius and Megamonas positively correlated with ALT (P < 0.05). The addition of 10% cassava pellets to the diet improved the growth performance and meat quality of broilers from 1 to 21 days of age and enhanced the microbial composition, providing valuable insights for optimizing broiler diets and improving economic returns.

The Microbial Perspective: A Systematic Literature Review on Hypertension and Gut Microbiota.

Understanding the causes of hypertension is important in order to prevent the disease. Gut microbiota (GM) seems to play an important role, but the detailed physiology remains elusive, with alpha diversity being the most studied indicator. This review aimed to systematically synthesize data on gut microbiota (alpha diversity) and hypertension. Databases, including MEDLINE/PubMed, Scopus, and EMBASE, and citations were systematically queried. We retrieved articles reporting the association between gut microbiota and hypertension. A valid critical appraisal tool was also used to investigate the quality of the included studies. Eighteen eligible studies met our inclusion criteria. In this report, we focused on the following indices of alpha diversity: Shannon, Chao1, Simpson, and Abundance-based Coverage Estimator (ACE) indices. Several studies observed a significantly lower Shannon index in hypertensive patients compared to the healthy control group. Nevertheless, no statistically significant difference was found for the Chao1, Simpson, and ACE indices between hypertensive patients and controls. A higher Firmicutes-to-Bacteroidetes ratio (F/B ratio) was consistently observed in hypertensive patients compared to healthy controls, indicating potential dysbiosis in the gut microbiota. Our systematic review indicates that hypertensive patients may exhibit an imbalance in gut microbiota, evidenced by decreased alpha diversity and an elevated F/B ratio. However, the absence of statistically significant differences in secondary diversity indices (Chao1, Simpson, and ACE) highlights the need for further research. Well-designed, large-scale studies are necessary to clarify these associations and explore the role of gut microbiota in hypertension development.

Macrophyte Diversity and Ecosystem Services in Wetlands of Eastern Ranchi: A Multi-site Analysis of Abundance, Frequency, and Importance Value Index Patterns

Macrophytes, visible aquatic and semi-aquatic plants, are integral components of wetland ecosystems, playing crucial roles in maintaining biodiversity, providing ecosystem services, and ensuring ecological stability. This research examines the distribution, abundance, frequency, diversity, and ecosystem services of macrophytes in several wetlands (W1-W7) located in the eastern part of Ranchi district, Jharkhand, India. The study sites include Bundu Lake, Hindalco Pond, Choga Bada Talab, Raja Bandh, Kita Uparbandh, Tamar Bada Talab, and Rukka Dam. A quantitative assessment using quadrat sampling and phytosociological methods was conducted from September 2022 to March 2023 to ensure accurate data collection and analysis. The study documented 78 macrophyte species belonging to 33 families and 58 genera. Emergent macrophytes were found to be the dominant life form, constituting 69% of the recorded species. Several species demonstrated high frequency and abundance across multiple study sites, including Pontederia crassipes Mart., Alternanthera philoxeroides (Mart) Griseb., Hydrilla verticillata (L.f.) Royle, Ipomoea aquaticaForssk., and Nymphoides hydrophyllum (Lour.) kuntze. To assess the diversity and ecological characteristics of the macrophyte communities, various diversity indices were calculated. These included the Shannon-Wiener index, Simpson's index, Margalef index, and Pielou's Evenness index. The results of these analyses revealed high levels of macrophyte diversity and evenness within the studied wetlands. Twenty-one macrophytes were identified as key species and nine species as rare species based on their IVI (Importance Value Index) scores. The key species were found to provide essential ecosystem services, including erosion control, water quality improvement, nutrient cycling, carbon sequestration, and habitat provision for other organisms. This research contributes significantly to our understanding of macrophyte diversity patterns and traits-based ecosystem services in wetland ecosystems. The findings of this study have important implications for the development and implementation of effective conservation strategies for these vital wetland ecosystems in the eastern Ranchi (W1- W7).

Influence of host-specific and locally isolated multi-strain probiotics on piglet performance, mortality, inflammatory response, and gut microbiome.

This study aimed to assess the impact of host-specific and locally isolated multi-strain probiotics on piglet performance, mortality, inflammatory responses, and gut microbiome. A total of 52 piglet litters-34 from Landrace sows and 18 from Large White sows-were allocated to two groups: a control group and a multi-strain probiotic group. The probiotic group comprised seven strains of lactic acid bacteria (MLAB): Lactobacillus brevis, Lactobacillus reuteri, Lactobacillus paraplantarum, Lactococcus lactis, Lactobacillus pentosus, Weissella cibaria, and Pediococcus pentosaceus. Each strain was included in equal concentrations, resulting in a final liquid mixture containing 109 CFU/mL. The MLAB group received the probiotics orally starting from 7 days of age until weaning at four weeks. Following weaning, supplementation continued via feed spraying for an additional four weeks. MLAB supplementation did not significantly affect piglet performance but showed a trend towards reducing the mortality rate (p = 0.06). It influenced the inflammatory response by upregulating the expression of anti-inflammatory cytokines interleukin (IL)-4 and IL-10 (p<0.05). Microbial community analysis indicated that MLAB supplementation increased both microbial diversity (Simpson index: p = 0.06) and species richness (Chao1 index: p = 0.02). Piglets receiving MLAB had a significantly higher abundance of the phylum Firmicutes (p<0.01) compared to the control group, while the abundance of the phylum Bacteroidota was markedly reduced (p<0.01). In addition, the relative abundance of the bacterial genera Prevotellaceae_NK3B31 (p<0.01) and Chlamydia (p = 0.03) was lower in the MLAB group. Overall, these results suggest that while MLAB supplementation does not directly improve piglet growth performance, it has the potential to improve immune function and promote a healthier gut microbiota in weaning piglets, which could ultimately reduce mortality rates.

Short-term effects of co-applied biochar and paper mill biosolids on soil microbial communities under field conditions

Biochar and paper mill biosolids (PB) are reported to improve soil fertility, crop growth and indirectly conditions for soil microbial communities. However, it is unclear how the co-application of these materials impacts soil microbial communities under field conditions. A study was initiated in 2018 in Québec, QC, Canada and fine roots and rhizosphere soil were sampled to determine the effects of co-application of wood biochar (0, 10, and 20 Mg dry wt. ha−1) and PB (0 and 30 Mg wet wt. ha−1) on the percentage of corn (Zea mays L.) and soybean (Glycine max L. Merr.) root colonization by arbuscular mycorrhizal fungi (AMF), soil microbial biomass phosphorus (MBP) and microbial (Bacteria, Fungi and AMF) diversity and community structure in a temperate loamy soil. Co-applying PB and biochar increased soil MBP compared with the control and biochar-only application. Applying PB alone or with biochar increased the level of root colonization by AMF compared with the control and biochar-only application in soybean but not in corn. Overall, biochar and PB application had no significant effect on bacterial and AMF diversity and community structure compared with the control. However, applying PB alone or with biochar decreased the fungal alpha diversity (Shannon and Simpson indices), affected several fungal taxa abundances and shifted the fungal community structure as indicated by the principal coordination analysis (PCoA). Our results provided an understanding on the short-term effects of co-applied wood biochar and PB on microbial communities of a temperate loamy soil under field conditions, as well as scientific bases for further investigation.

Effects of urban green space habitats and tree species on ectomycorrhizal fungal diversity

Ectomycorrhizal fungi (EMF) are key symbiotic microbial components for the growth and health of trees in urban greenspace habitats (UGSHs). However, the current understanding of EMF diversity in UGSHs remains poor. Therefore, in this study, using morphological classification and molecular identification, we aimed to investigate EMF diversity in three EMF host plants: Cedrus deodara in the roadside green belt, and C. deodara, Pinus massoniana, and Salix babylonica in the park roadside green belt, in Guiyang, China. A total of 62 EMF Operational Taxonomic Units (OTUs) were identified, including 13 EMF OTUs in the C. deodara roadside green belt, and 23, 31, and 9 EMF OTUs in the park green belts. C. deodara, P. massoniana, and S. babylonica were respectively identified in park green belts. Ascomycota and Basidiomycota were the dominant phylum in the EMF communities in roadside and park green habitat, respectively. The Shannon and Simpson indexes of the C. deodara EMF community in the park green belt were higher than those in the roadside green belt. EMF diversity of the tree species in the park green belt was P. massoniana > C. deodara > S. babylonica. Differences in EMF community diversity was observed among the different greening tree species in the UGSHs. UGSHs with different disturbance gradients had a significant impact on the EMF diversity of the same greening tree species. These results can be used as a scientific reference for optimizing the design and scientific management of UGSHs.

Dietary β-mannanase reduced post-weaning diarrhea of pigs by positively modulating gut microbiota and attenuating systemic immune responses

BackgroundAfter weaning, nursery pigs have difficulty digesting non-starch polysaccharides in their diets, which can result in growth and health problems. Among non-starch polysaccharides, β-mannan is easily found in various cereal grains that form the basis of livestock diets and interferes the digestion and utilization of nutrients. Supplementation of dietary β-mannanase in nursery diet can alleviate the negative effects on nutrient utilization efficiency caused by β-mannan and improve growth and health of pigs. This study was conducted to evaluate effects of dietary β-mannanase supplementation on growth performance, nutrient digestibility, intestinal morphology, fecal microbiota, and systemic immune responses of weaned pigs.ResultsDietary β-mannanase (MAN) improved average daily gain (P = 0.053), average daily feed intake (P < 0.05), and gain to feed ratio (P = 0.077) of pigs for 3 weeks after weaning and apparent total tract digestibility of crude protein (P = 0.060) and reduced post-weaning diarrhea (P < 0.05). The MAN did not affect the ileal morphology. Pigs fed with MAN had more diverse fecal microbiota based on the results of alpha diversity [the number of operational taxonomic units (OTUs; P = 0.061), Shannon (P = 0.071), and Simpson indices (P = 0.078)] and relative abundance of phylum Bacteroidetes (P = 0.064) and genus Prevotella (P < 0.05) than pigs fed control diet (CON). As a result of beta diversity, fecal microbiota was clustered (P < 0.05) into two distinct groups between dietary treatments. The MAN decreased (P < 0.05) packed cell volume (PCV), the number of white blood cells (WBC), C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1), and cortisol of the pigs for 2 weeks after weaning compared with CON.ConclusionDietary β-mannanase reduced post-weaning diarrhea of pigs by positively modulating gut microbiota and attenuating systemic immune responses.

Effects of the Radicle Sheath on the Rhizosphere Microbial Community Structure of Seedlings in Early Spring Desert Species Leontice incerta

Most research on plant–microbe interactions emphasize the effects of micronutrients on the rhizosphere microbial community structure. However, the influence of seed structures, particularly the radicle sheath, on microbial diversity at the seedling root tips under varying temperatures and humidity has been less explored. This study conducted controlled indoor experiments in the northern desert of Xinjiang to assess the radicle sheath’s impact on microbial community composition, diversity, and function. The results indicated no significant changes in the Chao1 index for bacteria and fungi, but notable differences were observed in the Shannon and Simpson indices (p &lt; 0.05). Under drought conditions, the radicle sheath significantly reduced bacterial infections without affecting fungi. Genus-level analysis showed an increased abundance of specific dominant bacterial groups when the radicle sheath was retained. NMDS analysis confirmed its significant effect on both bacterial and fungal community structures. LEfSe analysis identified 34 bacterial and 15 fungal biomarkers, highlighting the treatment’s impacts on microbial taxonomic composition. Functional predictions using PICRUSt 2 revealed that the radicle sheath facilitated the conversion of CH4 to CH3OH and various nitrogen cycle processes under drought. Overall, the radicle sheath plays a crucial role in maintaining rhizosphere microbial community stability and enhancing the functions of both bacteria and fungi under drought conditions.

Immunomodulatory Effects of a Prebiotic Formula with 2'-Fucosyllactose and Galacto- and Fructo-Oligosaccharides on Cyclophosphamide (CTX)-Induced Immunosuppressed BALB/c Mice via the Gut-Immune Axis.

Obejectives: This study explored the immunomodulatory effects of a prebiotic formula consisting of 2'-fucosyllactose (2'-FL), galacto-oligosaccharides (GOSs), and fructo-oligosaccharides (FOSs) (hereinafter referred to as 2FGF) in cyclophosphamide (CTX)-induced immunosuppressed BALB/c mice and its underlying mechanisms. Methods: Sixty healthy female BALB/c mice were randomly divided into the following groups: normal control (NC) group; CTX treatment (CTX) group; 2FGF low-dose (2FGF-L) group; 2FGF medium-dose (2FGF-M) group; and 2FGF high-dose (2FGF-H) group. An immunosuppressed model was established in the 2FGF-H group by intraperitoneal injection of 80 mg/kg CTX. After 30 days of 2FGF intervention, peripheral blood, spleen tissue, thymus tissue, and intestinal tissue from the mice were collected and analyzed. The changes in weight and food intake of the mice were recorded weekly. Hematoxylin-eosin (HE) staining was used to observe the histological change of the spleen tissue. Enzyme-linked immunosorbent assay (ELISA) was employed to detect cytokine levels in peripheral blood. Flow cytometry was used to analyze T lymphocyte subgroup ratio of splenic lymphocytes. Western blot analysis was conducted on intestinal tissues to assess the expression of proteins involved in the tight junction, toll-like receptor 4 (TLR4), mitogen-activated protein kinase (MAPK), and nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) signaling pathways. Additionally, molecular techniques were used to analyze the intestinal microbiota. Results: The results showed that 2FGF restored CTX-induced splenic injury, increased the number of splenic T lymphocytes, and elevated serum cytokines such as interleukin-4 (IL-4) and IL-10. In the intestine, 2FGF upregulated the expression of intestinal epithelial tight junction proteins such as Claudin-1 and zonula occludens 1 (ZO-1), thereby enhancing intestinal barrier function and activating the MAPK and NF-κB pathways via TLR4. Furthermore, 2FGF elevated the α-diversity (Shannon and Simpson indices) of the gut microbiota in CTX-induced immunosuppressed mice, enriching bacteria species positively correlated with anti-inflammatory cytokines (e.g., IL-4) such as g_Streptomyces and g_Bacillus and negatively correlated with pro-inflammatory cytokines (e.g., IL-1β) such as g_Saccharomyces. The results suggest that 2FGF may enhance immunity via the gut-immune axis. Conclusions: The 2FGF prebiotic formula showed an immunomodulatory effect in CTX-induced immunosuppressed mice, and the mechanism of which might involve optimizing the gut flora, enhancing intestinal homeostasis, strengthening the intestinal barrier, and promoting the expression of immune factors by regulating the TLR-4/MAPK/NF-κB pathway.