Fungal Communities Research Articles

Chytrid fungi infecting Arctic microphytobenthic communities under varying salinity conditions

This study aimed to investigate the presence and diversity of fungal parasites in Arctic coastal microphytobenthic communities. These communities represent a key component in the functioning of Arctic trophic food webs. Fungal parasites, particularly Chytridiomycota (chytrids), play significant roles by controlling microalgal bloom events, impacting genetic diversity, modifying microbial interactions, and accelerating nutrient and energy transfer to higher trophic levels. In the context of rapid Arctic warming and increased glacier meltwater, which significantly affects these communities, we used high-throughput sequencing to explore fungal community composition. Our results show that chytrids dominate fungal communities in Arctic benthic habitats and that the overall fungal diversity is primarily influenced by the salinity gradient. Chytrid representation is positively correlated with the presence of potential benthic diatom (Surirella, Nitzschia, Navicula) and green algae (Ulvophyceae) hosts, while microscopic observations provide further evidence for the presence of active chytrid infections.

Unraveling the Role of Contaminants Reshaping the Microflora in Zea mays Seeds from Heavy Metal–Contaminated and Pristine Environment

Heavy metal (HM) contaminants are the emerging driving force for reshaping the microflora of plants by eradicating the non-tolerance and non-resistant microbes via their lethal effects. Seeds served as a prime source of ancestral microbial diversity hereditary transfer from generation to generation. However, the problem arises when they got exposed to metal contamination, does metal pollutant disrupt the delicate balance of microbial communities within seeds and lead to shifts in their microflora across generations. In this study, the endophytic community within Zea mays seeds was compared across three distinct regions in Yunnan province, China: a HM-contaminated site Ayika (AK), less-contaminated site Sanduoduo (SD), and a non-contaminated Site Dali (DL). High-throughput sequencing techniques were employed to analyze the microbial communities. A total of 492,177 high-quality reads for bacterial communities and 1,001,229 optimized sequences for fungal communities were obtained. These sequences were assigned to 502 and 239 operational taxonomic units (OTUs) for bacteria and fungi, respectively. A higher diversity was recorded in AK samples than in SD and DL. Microbial community structure analysis showed higher diversity and significant fluctuation in specific taxa abundance in the metal-polluted samples exhibiting higher response of microbial flora to HM. In AK samples, bacterial genera such as Gordonia and Burkholderia-Caballeronia-Paraburkholderia were dominant, while in SD Pseudomonas and Streptomyces were dominant. Among the fungal taxa, Fusarium, Saccharomycopsis, and Lecanicillium were prevalent in HM-contaminated sites. Our finding revealed the influential effect of HM contaminants on reshaping the seed microbiome of the Zea mays, showing both the resilience of certain important microbial taxa as well the shifts in the diversity in the contaminated and pristine conditions. The knowledge will benefit to develop effective soil remediation, reclamation, and crop management techniques, and eventually assisting in the extenuation of metal pollution's adverse effects on plant health and agricultural productivity.

Soil Properties and Rhizosphere Microbes Community Structure Reveal Nitrogen Uptake Preferences and Nitrogen Use Efficiency of Two Ecotypes of Paphiopedilum micranthum

Paphiopedilum micranthum, an IUCN Red List species, is discontinuously distributed in the karst limestone mountain of southwest China and exhibits ecological specialization, typically through lithophytic and terrestrial ecotypes. Whether the distribution of rhizosphere bacteria and fungi in these different habitats is random or reflects soil preferences requires further investigation. A total of 73 samples from the core distribution areas in China, representing all habitats in two sites, were analyzed for soil differences by comparing edaphic properties and microbial community structure based on high-throughput sequencing of bacterial 16S rRNA genes and fungal ITS region sequences, alongside soil physiochemical data. The results showed no significant differences in microbial community richness and diversity across the heterogeneous habitats. However, significant differences in taxa were observed across various habitats. Dominant bacterial phyla included Actinobacteriota, Proteobacteria and Acidobacteriota, with dominant genera such as Crossiella, Pseudonocardia, 67-14, Mycobacterium and RB41. The primary fungal phyla were Basidiomycota and Ascomycota, featuring prominent genera such as Phlegmacium, Archaeorhizomyces, Trechispora, and Lepiota. There were 16 bacterial genera and 13 fungal genera associated with nitrogen transformation and fixation. Alkali-hydrolyzed nitrogen (AN) was identified as a main driver of soil bacterial and fungal community variation. Based on an analysis of soil physicochemical properties, ammonium nitrogen content was consistently higher than nitrate nitrogen across different habitats. Furthermore, across all heterogeneous habitats, P. micranthum showed no significant differences in nitrate nitrogen, ammonium nitrogen, or their ratio. The nitrogen-use efficiency of P. micranthum ranged from 7.73% to 9.87%, with the highest efficiency observed in the terrestrial habitat of Shedu. These results suggest that P. micranthum prefers habitats rich in organic matter and nitrogen, showing a preference for ammonium nitrogen uptake in natural conditions. Heterogeneous habitats affect plant nitrogen-use efficiency as well as changes in microbial community composition.

Fungal communities of Scots pine needles from a marginal, understudied population in Türkiye

Fungal communities of Scots pine needles from a marginal, understudied population in Türkiye

Lactation-related dynamics of bacterial and fungal microbiomes in feces of sows and gut colonization in suckling and newly weaned piglets.

Changes in the gut microbial composition of the sow during lactation may influence the gut microbial colonization in their offspring, for which less information was available in the literature. This study aimed to assess: 1) the changes that occur in the bacterial and fungal communities in sow feces during the 28-day lactation period as well as in gastric and cecal digesta of piglets until one week after weaning, and 2) bacterial and fungal taxa in cecal digesta of the piglets postweaning that associate with fecal consistency. Aside from sow milk, piglets had access to creep feed from day of life (DoL) 3. Fecal samples from sows for microbial analysis were collected (n=20) on days postpartum (DPP) 1, 6, 13, 20 and 27, as well as from weaned piglets for fecal scoring on DoL 30 and 34. Gastric and cecal digesta of piglets was collected on DoL3, 7, 14, 21, 28, 31 and 35 (n=5/sex/DoL). Progressing lactation affected bacterial and fungal communities in sow feces, including 10.3- and 3.0-fold increases in the relative abundances of Lactobacillus from DPP1 to 6 and Kazachstania from DPP1 to 13, respectively (P < 0.001). Although time- and gut site-related differences existed, bacterial and fungal taxa found in sow feces were also present in gastric and cecal digesta of piglets, which supports their role for gut colonization in neonatal piglets. In piglets, bacterial and fungal alpha-diversities showed certain fluctuations during the suckling period, whereby weaning affected more the fungal than bacterial diversity at both gut sites (P < 0.05). At both gut sites, Lactobacillus largely increased from DoL3 to 7 and remained a dominating taxon until DoL35 (P < 0.05). Postweaning, plant-glycan fermenters (e.g., Prevotella-9) seemed to replace milk-glycan fermenting Fusobacterium and Bacteroides (P < 0.05). In gastric and cecal digesta, Kazachstania, Tausonia, Candida and Blumeria were dominating fungi from DoL3 to 35, with Kazachstania becoming even more dominant postweaning (P < 0.001). Fecal consistency was softer on DoL34 than 30 (P < 0.05). Correlation analysis identified that softer feces were linked to the relative abundances of plant-glycan and proteolytic bacterial taxa including pathobionts (e.g., Clostridium sensu stricto) in the cecum on DoL34. However, the potential association between cecal mold and plant-pathogenic fungi Talaromyces, Mrakia, and Blumeria and softer feces are worth to investigate in the future in relation to (gut) health of piglets.

Soil microbial community composition by crop type under rotation diversification

BackgroundCrop rotation is an important agricultural practice that often affects the metabolic processes of soil microorganisms through the composition and combination of crops, thereby altering nutrient cycling and supply to the soil. Although the benefits of crop rotation have been extensively discussed, the effects and mechanisms of different crop combinations on the soil microbial community structure in specific environments still need to be analyzed in detail.Materials and methodsIn this study, six crop rotation systems were selected, for which the spring crops were mainly tobacco or gramineous crops: AT (asparagus lettuce and tobacco rotation), BT (broad bean and tobacco rotation), OT (oilseed rape and tobacco rotation), AM (asparagus lettuce and maize rotation), BM (broad bean and maize rotation), and OR (oilseed rape and rice rotation). All crops had been cultivated for > 10 years. Soil samples were collected when the rotation was completed in spring, after which the soil properties, composition, and functions of bacterial and fungal communities were analyzed.ResultsThe results indicate that spring cultivated crops play a more dominant role in the crop rotation systems than do autumn cultivated crops. Crop rotation systems with the same spring crops have similar soil properties and microbial community compositions. pH and AK are the most important factors driving microbial community changes, and bacteria are more sensitive to environmental responses than fungi. Rotation using tobacco systems led to soil acidification and a decrease in microbial diversity, while the number of biomarkers and taxonomic indicator species differed between rotation patterns. Symbiotic network analysis revealed that the network complexity of OT and BM was the highest, and that the network density of tobacco systems was lower than that of gramineous systems.ConclusionsDifferent crop rotation combinations influence both soil microbial communities and soil nutrient conditions. The spring crops in the crop rotation systems had stronger dominating effects, and the soil bacteria were more sensitive than the fungi were to environmental changes. The tobacco rotation system can cause soil acidification and thereby affect soil sustainability, while the complexity of soil microbial networks is lower than that of gramineous systems. These results provide a reference for future sustainable applications of rotation crop systems.

Ectomycorrhizal fungal communities associated with Crocanthemum and Lechea (Cistaceae) in subtropical Florida sandhill habitats.

Cistaceae are shrubs, subshrubs and herbs that often occur in stressful, fire-prone or disturbed environments and form ectomycorrhizal (ECM) associations with symbiotic fungi. Although some Cistaceae are long-lived shrubs that grow to significant size, others are herbaceous annuals or short-lived plants. Thus, Cistaceae are atypical ECM hosts that are fundamentally different in their biology from trees that are the more typically studied ECM hosts. The Mediterranean region is the center of diversity for Cistaceae and the ectomycorrhizal fungi associated with Cistaceae hosts have primarily been studied in Europe, North Africa, and the Middle East. Mediterranean Cistaceae often host diverse communities of ECM fungi, but they also act as hosts for some ECM fungi that putatively show host-specificity or strong host preference for Cistaceae (including species of Delastria, Hebeloma, Terfezia, and Tirmania). The ECM associations of Cistaceae in North America, however, remain highly understudied. Here we use fungal DNA metabarcoding to document the ectomycorrhizal fungal communities associated with Crocanthemum and Lechea (Cistaceae) in open, fire-prone sandhill habitats in north Florida. At each site we also sampled nearby Pinus to determine whether small, herbaceous Cistaceae have specialized ECM fungi or whether they share their ECM fungal community with nearby pines. The ECM communities of Florida Cistaceae are dominated by Cenococcum (Ascomycota) and Russula (Basidiomycota) species but were also significantly associated with Delastria, an understudied genus of mostly truffle-like Pezizales (Ascomycota). Although many Cistaceae ECM fungi were shared with neighboring pines, the ECM communities with Cistaceae were nonetheless significantly different than those of pines.

Continental sampling reveals core bacterial and environmentally driven fungal leaf endophytes in Heuchera.

Endophytic plant-microbe interactions range from mutualistic relationships that confer important ecological and agricultural traits to neutral or quasi-parasitic relationships. In contrast to root-associated endophytes, the role of environmental and host-related factors in the acquisition of leaf endophyte communities at broad spatial and phylogenetic scales remains sparsely studied. We assessed endofoliar diversity to test the hypothesis that membership in these microbial communities is driven primarily by abiotic environment and host phylogeny. We used a broad geographic coverage of North America in the genus Heuchera L. (Saxifragaceae), representing 32 species and varieties across 161 populations. Bacterial and fungal communities were characterized using 16S and ITS amplicon sequencing, respectively, and standard diversity metrics were calculated. We assembled environmental predictors for microbial diversity at collection sites, including latitude, elevation, temperature, precipitation, and soil parameters. Assembly patterns differed between bacterial and fungal endophytes. Host phylogeny was significantly associated with bacteria, while geographic distance was the best predictor of fungal community composition. Species richness and phylogenetic diversity were consistent across sites and species, with only fungi showing a response to aridity and precipitation for some metrics. Unlike what has been observed with root-associated microbial communities, in this system microbes show no relationship with pH or other soil factors. Overall, this work improves our understanding of the large-scale patterns of diversity and community composition in leaf endophytes and highlights the relative significance of environmental and host-related factors in driving different microbial communities within the leaf microbiome.

Redistribution of phosphorus fraction driven by organic carbon and microbial community during composting

Available information on the coupling relationship between phosphorus fraction and organic carbon during composting remains limited. Thus, this research investigated the changes of phosphorus fraction, dissolved organic carbon fluorescent components and microbial community in swine manure composting with different carbon sources including the maize straw (MS), garden waste (GW) and distillers’ grains (DG), in order to investigate whether the distribution and availability of phosphorus are influenced by different carbon sources used in the composting of swine manure. The result showed that different carbon sources changed phosphorus availability variously mainly by altering the succession of fungal communities and phosphorus functional genes. The dissolved organic material including tyrosine and tryptophan facilitate the mineralization of organic phosphorus (Org-P) into water-soluble phosphorus, thereby improving phosphorus availability. However, humic acid-like carbon components promote the conversion of inorganic-phosphorus to Org-P, which is the direct cause of the reduced phosphorus availability during composting. The results of this study provide support for the development of phosphorus-rich, stable, and clean compost products.

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.

Effect of Intercropping Soybean on the Diversity of the Rhizosphere Soil Arbuscular Mycorrhizal Fungi Communities in Wheat Field

Effect of Intercropping Soybean on the Diversity of the Rhizosphere Soil Arbuscular Mycorrhizal Fungi Communities in Wheat Field

Environment, plant genetics, and their interaction shape important aspects of sunflower rhizosphere microbial communities.

Associations with soil microorganisms are crucial for plants' overall health and functioning. While much work has been done to understand drivers of rhizosphere microbiome structure and function, the relative importance of geography, climate, soil properties, and plant genetics remains unclear, as results have been mixed and comprehensive studies across many sites and genotypes are limited. Rhizosphere microbiomes are crucial for crop resistance to pathogens, stress tolerance, nutrient availability, and ultimately yield. Here, we quantify the relative roles of plant genotype, environment, and their interaction in shaping soil rhizosphere communities, using 16S and ITS gene sequencing of rhizosphere soils from 10 genotypes of cultivated sunflower (Helianthus annuus) at 15 sites across the Great Plains of the United States. While site generally outweighed genotype overall in terms of effects on archaeal, bacterial, and fungal richness, community composition, and taxa relative abundances, there was also a significant interaction such that genotype exerted a significant influence on archaeal, bacterial, and fungal microbiomes in certain sites. Site effects were attributed to a combination of spatial distance and differences in climate and soil properties. Microbial taxa that were previously associated with resistance to the fungal necrotrophic pathogen Sclerotinia were present in most sites but differed significantly in relative abundance across sites. Our results have implications for plant breeding and agronomic microbiome manipulations for agricultural improvement across different geographic regions.IMPORTANCEDespite the importance of plant breeding in agriculture, we still have a limited understanding of how plant genetic variation shapes soil microbiome composition across broad geographic regions. Using 15 sites across the Great Plains of North America, we show that cultivated sunflower rhizosphere archaeal, bacterial, and fungal communities are driven primarily by site soil and climatic differences, but genotype can interact with site to influence the composition, especially in warmer and drier sites with lower overall microbial richness. We also show that all taxa that were previously found to be associated with resistance to the fungal pathogen Sclerotinia sclerotiorum were widespread but significantly affected by site, while a subset was also significantly affected by genotype. Our results contribute to a broader understanding of rhizosphere archaeal, bacterial, and fungal community assembly and provide foundational knowledge for plant breeding efforts and potential future microbiome manipulations in agriculture.

Zooming in on the temporal dimensions of plant–soil feedback: Plant sensitivity and microbial dynamics

Abstract The magnitude of plant–soil feedback (PSF) can depend on the time of conditioning as well as the length of feedback. Understanding the temporal variation in PSF requires insight in the response of both soil characteristics and the plant. We examined how conspecific PSF varies with the length of conditioning and the size of the response plant using Jacobaea vulgaris, a species known to experience negative conspecific PSF. Together with reanalysis of an existing microbial sequence dataset, we tested whether the temporal variation in PSF is due to size‐dependent plant sensitivity to conditioned soil or due to compositional changes in microbial communities of conditioned soil. Further, by reanalysing another existing dataset, we examined temporal dynamics of the relative growth rates (RGR) of J. vulgaris during the feedback phase. Testing varying conditioning lengths, uncovered that J. vulgaris exhibited the strongest negative PSF at 5 weeks of conditioning, after which PSF gradually attenuated. Plant sensitivity to conditioned soil decreased with increasing plant age/size of the response plant. In the feedback phase, the RGR of J. vulgaris was first higher, then lower and at the end similar in ‘away’ soil compared to ‘home’ soil. The dissimilarity in bacterial and fungal communities in ‘home’ and ‘away’ soil significantly decreased during the feedback phase. When J. vulgaris grew in ‘away’ soil, the relative abundance of 10 (out of 80) bacterial OTUs that positively correlated with plant growth decreased over time, while 5 (out of 86) OTUs that negatively correlated with plant growth the relative abundance increased over time. Additionally, only one (out of 10) fungal OTU that negatively associated with plant growth increased over time in ‘away’ soil. Synthesis. Our findings illustrate that PSF varies with the duration of soil conditioning and of the feedback phase. During the feedback phase, changes in PSF can be attributed to both the size‐dependent plant sensitivity to conditioned soil and temporal changes in the microbial community of conditioned soil. This highlights the importance of considering the reconditioning of soil microbial communities by the test plants during the feedback phase for understanding temporal variation in PSF.

The epidemic occurrence of decline disease in bayberry trees altered plant and soil related microbiome and metabolome

BackgroundIn China, decline disease with unknown etiology appeared as an epidemic among bayberry trees in the southern area of the Yangtze River. Furthermore, the use of beneficial microbes has been reported to be able to reduce the incidence of this disease, emphasizing the association of this disease with microorganisms. Therefore, it has become critical to uncover the microbiome’s function and related metabolites in remodeling the immunity of bayberry trees under biotic or abiotic stresses.ResultsThe amplicon sequencing data revealed that decline disease significantly altered bacterial and fungal communities, and their metabolites in the four distinct niches, especially in the rhizosphere soils and roots. Furthermore, the microbial communities in the four niches correlated with the metabolites of the corresponding niches of bayberry plants, and the fungal and bacterial networks of healthy trees were shown to be more complex than those of diseased trees. In addition, the role of microbiome in the resistance of bayberry trees to the occurrence of decline disease was justified by the isolation, identification, and characterization of important microorganisms such as significantly enriched Bacillus ASV804, Pseudomonas ASV815 in healthy plants, and significantly enriched Stenotrophomonas ASV719 in diseased plants.ConclusionOverall, our study revealed that the occurrence of decline disease altered the microbiome and its metabolites in four ecological niches in particular rhizosphere soils and roots of bayberry, which provides new insight into the control of bayberry decline disease.

Soil Properties Regulate Soil Microbial Communities During Forest Succession in a Karst Region of Southwest China

Natural vegetation restoration has emerged as an effective and rapid approach for ecological restoration in fragile areas. However, the response of soil microorganisms to natural succession remains unclear. To address this, we utilized high-throughput sequencing methods to assess the dynamics of soil bacterial and fungal communities during forest succession (shrubland, secondary forest, and primary forest) in a karst region of Southwest China. Our study revealed that bacterial α-diversity was significantly higher in secondary forest compared to both shrubland and primary forest. Intriguingly, the soil bacterial community in primary forest exhibited a closer resemblance to that in shrubland yet diverged from the community in secondary forest. Conversely, the soil fungal community underwent notable variations across the different forest stages. Furthermore, analysis of the microbial co-occurrence network revealed that, within these karst forests, the relationships among soil fungi were characterized by fewer but stronger interactions compared to those among bacteria. Additionally, soil properties (including pH, soil organic carbon, total nitrogen, moisture, and available potassium), soil microbial biomass (specifically phosphorus and nitrogen), and plant diversity were the drivers of soil bacterial community dynamics. Notably, soil pH accounted for the majority of the variations observed in the soil fungal community during karst forest succession. Our findings provide valuable insights that can inform the formulation of strategies for ecological restoration and biodiversity conservation in karst regions, particularly from a microbial perspective.

Effects of low light, interspecific competition, and their combination on flavonoid exudation patterns and rhizosphere fungal community in Juglans mandshurica and Fraxinus mandshurica roots

Effects of low light, interspecific competition, and their combination on flavonoid exudation patterns and rhizosphere fungal community in Juglans mandshurica and Fraxinus mandshurica roots

Medicinal Plant Microbiomes: Factors Affecting Bacterial and Fungal Community Composition.

This exploratory study was designed to identify factors implicating microbial influence on medicinal plant metabolomes. Utilizing a whole-microbiome approach, amplicon sequencing was used to identify the makeup of fungal and bacterial assemblages from endophytic (interior) and epiphytic (external) environments in two different sets of congeneric host-plant pairs, with collection of multiple samples of two medicinal plant species (Actaea racemosa, Rhodiola rosea) and two generic analogs (Actaea rubra, Rhodiola integrifolia). Diversity analysis of microbial assemblages revealed the influence of three primary factors driving variance in microbial community composition: host-plant taxonomy, the compartmentalization of microbial communities within discrete plant parts, and the scale of distance (microhabitat heterogeneity) between sampling locations. These three factors accounted for ~ 60% of variance within and between investigated microbiomes. Across all our collections, bacterial populations were more diverse than fungi (per compartment), and microbial density in epiphytic compartments (aerial parts, rhizosphere) were higher than those of endophytes (leaf and root). These comparative data point to key loci associated with variation between congeneric pairs and plant genera, providing insight into the complex and contrasting relationships found within this multi-kingdom coevolutionary relationship. Although reflective of only a limited set of botanical source materials, these data document the richness of a relatively unexplored component of the plant world and highlight the relevance of a whole-microbiome ecology-driven approach to botanical research and directed natural product investigations.

Shift of bacterial and fungal communities upon soil amelioration is driven by carbon degradability of organic amendments

The structural response of bacterial and fungal soil communities to four carbon-rich organic amendments of increasing recalcitrance was investigated. Wheat straw, green compost, a mixed product based on biogas residues, and a fermented biochar were applied to a sandy agricultural soil of low organic carbon content. After laboratory incubation for 6 months, the community structure was investigated via DNA sequencing. All amendments caused changes in the communities of bacteria and fungi, but to different extents, with the communities exposed to more recalcitrant amendments showing the least variation compared to the non-amended soil. Changes in species composition as well as their relative abundances were observed. While the straw had a pronounced effect on bacteria (e.g., the highest number of indicator species), effects of the composted, fermented, or pyrolyzed materials were minor. Hierarchical clustering showed that the fungal communities were more different from each other than the bacterial ones with the straw-soil being most different and the biochar-soil least different from the non-amended soil. While the abundant fungal species in biochar-soil and non-amended soil were very alike, especially rare fungal species shifted upon addition of biochar. An indicator species analysis identified specific taxonomic groups which were triggered by the different organic materials. We conclude that bacterial and fungal communities strongly change upon input of degradable carbon (straw), while fungi in particular respond to the application of processed organic materials. With this study, we report the consequences of applying organic materials for the microbial community in one soil. We provide these data for meta-analyses that are required to unravel all relevant interactions across different soils, organic materials, and time. This will allow to better understand and predict the effects of organic soil amelioration measures on soil microorganisms.

Distribution characteristics of soil active organic carbon at different elevations and its effects on microbial communities in southeast Tibet.

Global mountain ecosystems have garnered significant attention due to their rich biodiversity and crucial ecological functions; however, there is a dearth of research on the variations in soil active organic carbon across altitudinal gradients and their impacts on microbial communities. In this study, soil samples at an altitude of 3,800 m to 4,400 m were collected from Sejira Mountain in the southeast Tibet, and soil active organic carbon components, soil microbial community diversity, composition and structure distribution and their relationships were systematically analyzed. The results revealed a non-linear relationship between the elevation and the contents of soil organic carbon (SOC) and easily oxidized organic carbon (ROC), with an initial increase followed by a subsequent decrease, reaching their peak at an altitude of 4,200 m. The Shannon diversity of bacteria exhibited a significant decrease with increasing altitude, whereas no significant change was observed in the diversity of fungi. The bacterial community primarily comprised Acidobacteria, Proteobacteria, Chloroflexi, and Actinobacteriota. Among them, the relative abundance of Proteobacteria exhibited a negative correlation with increasing altitude, whereas Actinobacteriota demonstrated a positive correlation with elevation. The fungal communities primarily consisted of Basidiomycota, Ascomycota, and Mortierellomycota, with Ascomycota prevailing at lower altitudes and Basidiomycota dominating at higher altitudes. The diversity and composition of bacterial communities were primarily influenced by altitude, SOC, ROC, and POC (particulate organic carbon). Soil carbon-to-nitrogen ratio (C/N), dissolved organic carbon (DOC), and available phosphorus (AP) emerged as key factors influencing fungal community diversity, while POC played a pivotal role in shaping the composition and structure of the fungal community. In conclusion, we believe that soil active organic carbon components had a greater impact on the bacterial community in the primary forest ecosystem in southeast Tibet with the elevation gradient increasing, which provided a theoretical basis for further understanding of the relationship between the microbial community and soil carbon cycle in the plateau mountain ecosystem under the background of climate change.

Effects of spent substrate of oyster mushroom (Pleurotus ostreatus) on ruminal fermentation, microbial community and growth performance in Hu sheep.

The study aimed to evaluate the effects of Pleurotus Spent Mushroom Substrate (P.SMS) on the rumen microbiota, encompassing bacteria and fungi, as well as their interactions in Hu sheep. A total of forty-five 3-month-old Hu sheep were randomly assigned to five groups. Each group was fed diets in which whole-plant corn silage (WPCS) was substituted with P.SMS at varying levels: 0% (CON), 5% (PSMS5), 10% (PSMS10), 15% (PSMS15), or 20% (PSMS20). The results indicated that higher proportions of P.SMS during the experimental period might have a detrimental effect on feed utilization efficiency, kidney function, and blood oxygen-carrying capacity. Notably, moderate levels of P.SMS, specifically below 15%, were associated with improvements in rumen NH3-N levels and absorption capacity. The results indicated that (1) PSMS20 exhibited a significantly higher feed-to-gain ratio compared to CON (P < 0.05); (2) PSMS15 showed a significantly higher NH3-N content than CON, PSMS5, and PSMS20. Additionally, PSMS10 and PSMS20 had elevated concentrations of NH3-N compared to CON and PSMS5 (P < 0.05); (3) The length and width of rumen papillae were significantly greater in PSMS20 compared to CON and PSMS5 (P < 0.05); (4) Creatinine levels were significantly higher in PSMS20 than in CON, PSMS5, and PSMS10 (P < 0.05); (5) By the conclusion of the experiment, hemoglobin concentration in PSMS20 showed a significant increase compared to CON (P < 0.05). Furthermore, the addition of P.SMS influenced microorganisms at both the phylum and genus levels: (1) At the phylum level, the prevalence of Patescibacteria was significantly lower in PSMS20 compared to the other groups; (2) PSMS15 exhibited significantly higher relative abundances of Basidiomycota compared to CON and PSMS10, while PSMS20 also demonstrated significantly higher relative abundances compared to CON (P < 0.05); (3) At the genus level, the prevalence of Candidatus_Saccharimonas in PSMS20 was significantly lower than in PSMS5, PSMS10, and PSMS15. Conversely, the prevalence of Phanerochaete in PSMS15 was notably higher than in CON and PSMS10, and it was also significantly elevated in PSMS20 compared to CON (P < 0.05); (4) Correlation analysis indicated no significant correlation between changes in the structure of bacterial and fungal communities. Considering these findings, a high percentage of P.SMS negatively impacted feed utilization efficiency, blood oxygen carrying capacity, and kidney function, while a moderate percentage of P.SMS promotes rumen absorption capacity, indicating that feeding 10% P.SMS is optimal.