Dominant Genera Research Articles

Dietary and environmental factors affecting the dynamics of the gut bacteria in Tibetan Awang sheep (Ovis aries) across divergent breeding models

IntroductionTibetan Awang sheep (Ovis aries), indigenous to the Qinghai-Tibet Plateau, are highly adapted to high-altitude environment. However, knowledge regarding their gut bacterial composition remains limited.MethodsA comprehensive 16S rRNA highthroughput sequencing was performed on fecal samples from 15 Awang sheep under pure grazing, semi-captivity, and full captivity breeding models.ResultsOur results revealed that Firmicutes and Bacteroidetes were the most abundant bacterial phyla, while Christensenellaceae_R-7_group, Romboutsia, Rikenellaceae_RC9_gut_group, Ruminococcus, and Bacteroides were prevalent genera in the gut microbiota of Awang sheep. Meanwhile, the predominant presence of Bacteroides with increasing altitude of breeding locations indirectly demonstrates its crucial role in mediating energy acquisition among Awang sheep at high altitudes. Furthermore, PCoA and ANOSIM analysis exhibited significant differences in bacterial composition across all breeding models (r > 0.6, p < 0.001). Christensenellaceae_R-7_group, Romboutsia, and Ruminococcus were significantly abundant in the pure grazing breeding model, while Rikenellaceae_RC9_gut_group and Bacteroides were more abundant in the semi-captivity breeding model. An abnormally high abundance of Acinetobacter indicated a potential risk of Acinetobacter infection in the fully captive group. The environmental association analysis exhibited that meadows diet (R2 = 0.938, Pr[>r] = 0.001) and altitude (R2 = 0.892, Pr[>r] = 0.001) had significant effects on the dominant genera, explaining a substantial proportion of the total variation in community composition.DiscussionOur study indicated that breeding conditions significantly impact the gut microbiota of Awang sheep. The environmental association analysis underscores the importance of diet and altitude in shaping the gut microbiota of Awang sheep. The present findings provide insights into the microbiota dynamics of Awang sheep and offer guidance for their scientific husbandry management.

Pathogenic Fungi Communities in Contrasted Yam Field Soils are Dominated by The Genus Fusarium in Centre Côte d’Ivoire

Below-ground pathogenic fungi of yam, a globally important food crop are shown to be responsible of field and storage diseases and as such are important threats to yam health. However, yam soil pathogenic fungi community composition and soil determinants remain unclear. Here, we explored the effects of soil physicochemical characteristics on soil fungal phytopathogens in contrasted yam fields. Illumina miseq was used to characterize pathogenic fungi communities in yam field soils. In this work, we hypothesise that pathogenic community composition could be linked to specific physicochemical properties within yam contrasted soils. Principal Coordinate Analysis (PCoA) and variance partitioning were used to identify the soil properties that significantly influence pathogenic fungi community compositions within the three sites in a yam production zone. The results have shown that despite the fact that the three sites exhibited contrasted soils grouped in two types according to physicochemical parameters, four ubiquitous genera including Fusarium, Penicillium, Aspergillus and Trichoderma were identified within pathogenic fungi communities in yam field soils, with Fusarium as the most dominant core genus. Soil type determined the distribution of pathogenic fungi communities in yam field soils, and this effect was attributed to soil properties related to yam soil cation exchange capacity (CEC) and silt content as well as three micronutrients including Na, N and total phosphorus.

Characterization of Lung Microbiome in Subclinical Pneumonic Thai Pigs Using 16S rRNA Gene Sequencing

Bacterial respiratory disease is one of the major concerns in the modern pig industry. To address the limitations of culture-based methods, 16S rRNA sequencing was employed to characterize the pig lung microbiome to gain a better understanding of microbial physiology and their population genetics. A batch of 510 slaughtered pigs from a farm located in Lampang province, Thailand, was selected. Individual pig weight was recorded. A total of 24 lungs (10 normal and 14 pneumonic lungs) were sampled for gross lesion examination and lung microbial communities were investigated. Poor growth performance and weight uniformity were denoted in this batch. Several pathogenic bacteria were detected in both normal and pneumonic lungs. Microbial diversity was decreased in the pneumonic group. PCoA and NMDS analysis showed a clear separation between the groups. Stenotrophomonas spp. (42.12%) was the dominant genus identified in normal lungs, while Mycoplasma hyopneumoniae (71.97%) was the most abundant in pneumonic lungs, correlating with the commonly observed consolidation lesions. The slaughterhouse serves as a key checkpoint for gathering comprehensive information on pig respiratory health, and lung is representative of the lower respiratory tract for microbiomics. Monitoring of lung lesions should be implemented routinely to gain a better understanding of regional pig respiratory health.

Molecular ecological insights into the synergistic response mechanism of nitrogen transformation, electron flow and antibiotic resistance genes in aerobic activated sludge systems driven by sulfamethoxazole and/or trimethoprim stresses

The prevalence of antibiotics poses a serious challenge to biological nitrogen removal in wastewater. In this study, the effects of sulfamethoxazole and/or trimethoprim (15 mg/L∼30 mg/L) on treatment performance, nitrogen transformation and antibiotic resistance genes (ARGs) were investigated in aerobic activated sludge systems to elucidate the metabolic mechanism under high antibiotic stress. 15 mg/L single antibiotic stress improved total nitrogen removal performance due to the persistence of nitrifiers and enrichment of denitrifiers, with an optimum removal efficiency of 96.5%. Up-regulation of all denitrifying genes, coupled with enhanced electron transfer of Complex II and III, contributed to the emergence of aerobic denitrification. The increased expression of antioxidant genes also alleviated intracellular pressure. Whereas combined antibiotic stress induced the significant down-regulation of denitrifying bacteria and genes (nirKS and nosZ), and suppressed the electron supply for denitrification by restraining genes related to Complex Ⅰ and energy supply by tricarboxylic acid cycle, driving the collapse of activated sludge system, with ammonia and total nitrogen removal efficiencies dropping to below 40% and 20%, respectively. The dominant genera in system changed from TM7a to Thiothrix and Sphaerotilus with increasing antibiotic concentration and type. Moreover, antibiotic stress promoted a slight enrichment of ARGs, especially those encoding efflux mechanisms. Cooperative relationships (> 93%) dominated among ARGs, and Klebsiella was identified as the crucial host. ARGs regulating antibiotic efflux were more likely to be co-expressed with functional genes. These results may provide a theoretical basis for establishing promising strategies to mitigate antibiotic-caused process deterioration.

Simultaneous removal of organic matter and inorganic nitrogen in Baijiu wastewater by methanotrophic denitrification.

Methanotroph could facilitate nitrogen removal during methane oxidation, and promote conversion of organic compounds by producing methane monooxygenase. Co-metabolic effect and mechanism of aerobic methane oxidation on the removal of nitrogen and organic matter from Baijiu wastewater were investigated using an improved denitrifying biological filter. It was found that the average removal efficiency of chemical oxygen demand (COD), total nitrogen (TN) and chroma increased by 17%, 22% and 10% in reactor B with methane compared to reactor A with air only. Three-dimensional fluorescence spectroscopy and Fourier transform infrared spectroscopy analysis revealed that methanotroph co-metabolism was accompanied by eliminating nitrogen and organic matter as well as forming alcohol compounds. Metagenomic analyses revealed that Methylocaldum, the dominant genera in Reactor B, exerted a pivotal role in removing nitrogen and organic matter removal by supplying energy and catalysis. Functional genes pmoABC-amoABC could facilitate nitrogen and organic matter removal.

The role of apricot kernels in shaping the microbial community composition during Massa Medicata Fermentata fermentation.

In order to investigate the effect of apricot kernels on microbial community composition during Massa Medicata Fermentata (MMF) fermentation and to preliminarily explore whether it is related to amygdalin. In this paper, the structural characteristics of MMF and the composition of its bacterial and fungal communities during fermentation were determined. The results showed that both microscopy and infrared techniques could identify the structure of the apricot kernel in MMF and whether the kernel had been debitterized or not; the dominant bacterial phyla in MMF were Firmicutes and Proteobacteria, with the dominant bacterial genera being Staphylococcus and Bacillus, and the dominant fungal phylum was Ascomycota, with the dominant fungal genus being Aspergillus. Meanwhile, the effect of apricot kernels on the bacterial community in MMF was closely related to that of amygdalin. Apricot kernels inhibited the growth of a wide range of bacteria during the MMF fermentation but promoted the growth and reproduction of Firmicutes and Staphylococcus. In contrast, fermentation of MMF with debitterized apricot kernels significantly increased the bacterial diversity and richness while it inhibited the growth and reproduction of Firmicutes and Staphylococcus. In summary, amygdalin is a key player in regulating microbial community diversity that occurs during the fermentation process of MMF, apricot kernel was an essential component of MMF.

Biogenic sulfide by sulfur disproportionation enhances nitrate removal and reduces N2O production during sulfur autotrophic denitrification.

Sulfur autotrophic denitrification (SADN) is regarded as a cost-effective bioremediation technology for nitrate-contaminated water. Nevertheless, the low bioavailability of sulfur is a major challenge that hinders nitrogen removal efficiency. A sulfur autotrophic disproportionation (SADP) process was proposed to convert sulfur to biogenic sulfide, greatly increasing the availability of electron donors. Throughout the 201-day laboratory-scale test, it was observed that the SADP process achieved desirable performance with 198.87±39.8mgS/L biogenic sulfide production per day, which could provide sufficient electron donors for the SADN process in treatment of 671.22±134.40mgN/L/d nitrate. Microbial community analysis confirmed the presence and dominancy of sulfur-disproportionating bacteria (SDB) (e.g., Desulfocaspa sp. taking up to 8.27% of the entire microbial community), while Thiobacillus was the most dominant genus of sulfur oxidizing bacteria (SOB), accounting for 87.32% of the entire community. Further experiments revealed that the addition of chemical and biogenic sulfides enhanced the nitrate removal rate of the SADN process by a factor of 1.31 and 1.34, respectively. Additionally, biogenic sulfide was found to be the most effective nitrous oxide (N2O) mitigator, reducing emission by 82% and 95% in denitrification and denitritation processes, respectively. The results demonstrated that the integrated SADP and SADN processes was a more effective and carbon-neutral alternative in treatment of nitrate-contaminated water.

Targeted volatile fatty acid production based on lactate platform in mixed culture fermentation: Insights into carbon conversion and microbial metabolic traits.

In this study, the effects of fermentation pH and redox potential on the performance of the lactate platform were comprehensively evaluated. The results indicated that the type of acidogenic fermentation was influenced by redox potential, while pH was correlated with volatile fatty acid yield. The highest propionate yield was achieved under anaerobic conditions at a pH of9, with the dominant genus Serpentinicella producing propionate through the acrylate pathway. The highest acetate yield was produced under facultative conditions at a pH of 6. This production was primarily facilitated by the dominant genera unclassified_f__Enterobacteriaceae and Desulfovibrio, which exhibited significant upregulation of the expression of related genes. Furthermore, ecological processes were employed to establish the relationship between environmental factors and microbial communities. This study emphasized the process of converting lactate into volatile fatty acid, providing a theoretical basis for future strategies aimed at regulating targeted acid production.

Effect of microbial community on the formation of flavor components in cigar tobacco leaves during air-curing

BackgroundThe air-curing process of cigar tobacco leaves is typically conducted in an open environment, involving the participation of various microorganisms. However, the effect of microbial communities during air-curing process on the formation of flavor components remains unclear. Therefore, this study aims to reveal the dynamics of flavor components and microbial community changes, and explore the potential role of microbial communities in flavor formation during the cigar tobacco air-curing process.ResultsHigh-throughput sequencing analysis showed that Pantoea, Sphingomonas and Pseudomonas were the dominant bacterial genera during air-curing process, while Aspergillus was the dominant fungal genus. Subsequently, volatile flavor analysis shows that alkaloids were the most important volatile compounds in cigar leaves, followed by esters, alcohols and aldehydes. Furthermore, 38 characteristic volatile flavor compounds at different periods of air-curing were identified based on PLS-DA in different periods of air-curing. The correlation analysis between microorganisms and flavor components showed that Pantoea and Staphylococcus might promote the flavor formation from browning to post-air-curing and were positively correlated with specific flavor components like phenylacetaldehyde and acetophenone. Phoma, Mycosphaerella, Wallemia, and Cladosporium were identified as key fungal genera influencing flavor formation, as they showed positive correlations with multiple flavor components. These information enrich our understanding of the flavor formation of cigar tobacco during air curing.ConclusionsThere is a complex correlation between the microbial community and the flavor components, which may have a great influence on the flavor formation during the air-curing process of cigar leaves. Bacterial communities have higher species diversity and richness during air-curing, and have more complex correlation characteristics with volatile flavor, which may play more roles in the flavor formation. This study revealed the potential role of microbial community on flavor formation in cigar tobacco air-curing process, and provided guidance for subsequent screening of specific functional microorganisms to improve and stabilize cigar tobacco flavor.

The Isolation and Identification of Pseudoalteromonas sp. H27, a Bacterial Strain Pathogenic to Crassostrea gigas

Bacterial infection is frequently observed in disease outbreaks of aquatic animals, making it of significance to isolate and identify the bacterial pathogens. In this study, diseased individuals of Crassostrea gigas were sampled from the nearshore area in Zhanjiang, Guangdong in May 2023. Culturable bacteria were isolated from the diseased tissue and a pathogenic strain labeled as H27 was screened through a hemolysis test and bacterial challenge experiments. Morphological characterization, 16S rRNA gene sequence-based molecular identification and biochemical tests showed that strain H27 belonged to the genus of Pseudoalteromonas, a dominant genus in the diseased tissue of C. gigas revealed by bacterial community structure analysis. The clinical signs originally observed in naturally diseased C. gigas were reproduced in strain H27-challenged adults, both with the red mantle and adductor. Histopathological analysis was further performed on the diseased tissues of the latter, which showed a significantly increased accumulation of pigment granules in the cytoplasm of the diseased mantle as well as enlarged muscle fiber distances in the diseased adductor. In addition, strain H27 was re-isolated from tissues of the moribund C. gigas after bacterial challenge, indicating the fulfillment of Koch’s postulate. Our results help to enrich the knowledge of C. gigas diseases, possibly contributing to disease prevention and control.

Varying effects of Vicia sativa and Vicia villosa on bacterial composition and enzyme activities in nutrient-deficient sugarcane soils under greenhouse conditions

Declining soil health and productivity are key challenges faced by sugarcane small-scale growers in South Africa. Incorporating Vicia sativa and Vicia villosa as cover crops can improve soil health by enhancing nutrient-cycling enzyme activities and nitrogen (N) contributions while promoting the presence of beneficial bacteria in the rhizosphere. A greenhouse experiment was conducted to evaluate the chemical and biological inputs of V. sativa and V. villosa in nutrient-deficient, KwaZulu-Natal (KZN) sugarcane plantation soils. The nutrient concentrations, N and phosphorus (P) cycling bacteria, and extracellular enzyme activities of 5 soils were determined pre-planting and post-V. sativa and V. villosa harvest. Post-harvesting soils had higher pH levels than pre-planting soils. The number of plant growth-promoting rhizobacteria increased post-V. sativa and V. villosa harvest, with Arthrobacter, Burkholderia, Paraburkholderia and Pseudomonas as the dominant genera. Acid phosphatase and glucosidase activities increased, with Mvutshini and Mzinto showing the most significant increases (phosphatase: 18.66 to 84.67 for V. villosa, 90.33 for V. sativa; glucosidase: 15.33 to 83 for V. villosa and 105 µmolh− 1g− 1 for V. sativa). In conclusion, V. sativa and V. villosa increased PGPR, pH and enzyme activities, making them viable cover crops for nutrient-deficient sugarcane soils.

Effects of pits of different ages on ethyl acetate and its metabolism-related microorganisms during strong-flavor Baijiu fermentation

The esters are the most important flavor components in Baijiu as their species and content decide the style of Baijiu. During the formation of esters, pits play important roles. In this study, the main esters and their related microorganisms in different years of pits (5, 35 and 100 years) of strong-flavor Baijiu were comprehensively researched by headspace solid-phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS) and amplicon sequencing. A total of 690 bacterial genera and 155 fungal genera were detected. The microbial composition of ZPs (fermented grains) from 100 years pit was the most abundant at the genus level. A total of 177 volatile flavor components were observed, including 80 esters, 42 alcohols, 21 acids, 10 ketones and 11 aldehydes. Ethyl acetate was the lowest and ethyl caproate was relatively high in 100 years pit. 15 genera, including Lactobacillus, Pichia, Issatchenkia, Saccharomyces, and Aspergillus, were positively related to the formation of four major esters and their precursors. The research demonstrated that 100 years pit was benefit for maintaining microbial diversity and controlling ethyl acetate. This study is helpful for understanding the microbial composition and succession in the fermentation process of strong-flavor Baijiu, and revealing the complex relationships between dominant genera, physicochemical properties and volatile flavor components.

Microbiota in patients with cefuroxime resistance and anal fistula revealed by 16S ribosomal DNA.

Anal fistula is increasingly prevalent due to modern lifestyle factors, and surgery remains the primary treatment. However, the rising incidence of antibiotic resistance, particularly to cefuroxime, complicates perioperative management. The role of gut microbiota in influencing this resistance is not well understood. To investigate the relationship between gut microbiota composition and cefuroxime resistance in anal fistula patients and to assess probiotic intervention impact. This study included 30 anal fistula patients categorized into cefuroxime-sensitive (Cefur-S) and cefuroxime-resistant (Cefur-NS) groups. Gut microbiota samples were collected during colonoscopy, and 16S ribosomal DNA sequencing was performed to analyze microbial diversity. Patients in the Cefur-NS group received a 7-day course of Clostridium butyricum tablets. Post-intervention, microbial composition and cefuroxime resistance were reassessed. Alpha and beta diversity analyses showed no significant differences in microbial diversity between the Cefur-S and Cefur-NS groups. However, effect size analysis identified Roseburia and Butyricicoccus as dominant genera in the Cefur-S group, with higher butyrate production potentially protecting against cefuroxime resistance. Post-intervention, the Cefur-NS group showed a significant reduction in cefuroxime resistance, improved stool consistency, and reduced bowel movement frequency. This study suggests that specific gut microbiota, particularly Butyricicoccus and Roseburia, may mitigate cefuroxime resistance in anal fistula patients by increasing butyrate production. Probiotic intervention targeting gut microbiota composition presents a promising strategy for reducing antibiotic resistance and improving clinical outcomes.

The Cry2Aa protein is not enough to pose a threat to Pardosa astrigera.

The widespread commercialization of genetically modified (GM) crops makes it important to assess the potential impact of Bacillus thuringiensis (Bt) on non-target organisms. Pardosa astrigera is an important predator in agroforestry ecosystems, and female and male spiders may react differently to Bt toxins due to their different activity habits and nutritional requirements. In this study, we found that exposure to Cry2Aa protein did not affect the survival and body weight of P. astrigera during growth and development. However, according to 16S rRNA sequencing results of the P. astrigera adults, Cry2Aa protein not only changed the diversity of symbiont bacteria, but also changed its symbiont composition. During feeding on prey without Bt artificial feed, the dominant communities in female and male adults were Actinobacteria and Corynebacterium-1, respectively. Feeding on prey containing Cry2Aa protein, Firmicutes were the dominant phyla. At the genus level, Cry2Aa protein significantly increased the relative abundance of Enterococcus and became the dominant genus in females only. In addition, Bacillus, Weissella and other symbiotic bacteria had significant changes in females. In terms of species composition, sex differences resulted in the absence of different types of symbiotic bacteria. Functional analysis of enrichment pathways showed significant changes in various metabolic pathways such as "Carbohydrate metabolism" and "Nucleotide metabolism", and there are differences between the sexes. These findings provide new data information and support for revealing the different strategies of spiders to cope with Cry2Aa protein based on sex differences, and also provide new data information and support for environmental safety assessment of GM crops.

Community structure and diversity of myxobacteria in soils from Inner Mongolia, China.

Myxobacteria are a special kind of Gram-negative bacteria that can slide and produce a variety of bioactive substances against bacteria, fungi, and viruses. It has great development and research value in medicine and agriculture. Although myxobacteria have become a research hotspot at home and abroad, there are few systematic studies on the relationship between its diversity, geographical location, and environment factors. In order to solve these problems, 133 soil samples were collected from the east to the west of Inner Mongolia Autonomous Region and divided into five groups. The water content, pH, organic matter, available phosphorus, hydrolytic nitrogen, and available potassium content of soil samples were determined by national standards and other methods. The quantitative assessment of the abundance of myxobacteria in the soil sample was performed by quantitative real-time PCR. The composition of myxobacteria in the soil was determined by 16S rRNA high-throughput sequencing technology to analyze the differences in the community structure of myxobacteria among different groups, explore the relationship between the diversity of myxobacteria resources and the distribution and physical and chemical properties of the soil, and predict and analyze its community function. The results showed that there were abundant myxobacteria resources in the soils of Inner Mongolia, and the average relative abundance of myxobacteria in the soil samples from the central part of Inner Mongolia was higher than that in the eastern and western parts, but the richness and diversity of samples from the central to eastern regions were significantly higher than those from the western regions. The myxobacteria resources in the whole region included 10 families and 22 genera, among which the dominant genera were Labilitrix, Sandaracinus, Archangium, and Haliangium. The analysis of the species composition of myxobacteria among different groups found that the distribution of soil and soil type had an impact on the species composition of the samples. The species with significant differences in relative abundance among the five groups of samples were Labilitrix, Archangium, Sandaracinus, Minicystis, Polyangium, and Myxococcus. In addition, the latitude and longitude of the sampling point and the soil pH, water content, available phosphorus content and organic matter content had a greater impact on the myxobacteria community structure of samples, while the altitude of the soil sample and the contents of available potassium and alkaline nitrogen had a relatively small impact. Our data suggest that the distribution, type and nutrient composition of soil samples have an impact on the relative abundance and species composition of myxobacteria community. The completion of this work can provide basic data for the in-depth study of myxobacteria in the soil.

Microbial community of Nongxiangxing daqu during storage: microbial succession, assembly mechanisms and metabolic functions.

The storage process of Nongxiangxing daqu is closely related to the quality of the daqu. The role of storage in daqu manufacture remains unclear, and most actual production relies on previous production experience. With the extension of daqu storage over a period of time, saccharifying activity, liquefying activity, fermenting activity, and esterifying activity reached a peak when stored for 3 to 4 months. Analysis of the flavor compounds showed that 87 flavor components were detected in daqu, and esters and alcohols were the main flavor compounds found. Microbial community analysis suggested that Weissella was the dominant bacterial genus with relative abundance increasing during storage, while Thermomyces was dominant fungal genus with abundance decreasing during storage. Analysis of assembly processes revealed that bacterial assembly was primarily influenced by stochastic processes during storage, whereas fungal assembly was predominantly shaped by deterministic processes. The interactions among microbiota, flavor compounds, and physicochemical parameters were elucidated, suggesting that saccharifying activity was positively correlated with Weissella, Lactobacillus, Kodamaea and Wickerhamomyces, and most of esters were positively correlated with Pediococcus and Clavispora. Microbial community functions were also predicted, highlighting enzymes involved in carbohydrate degradation, flavor formation, and ethanol fermentation. Finally, simulated baijiu fermentation was performed by adding daqu stored for different times, and the results showed that daqu stored for 3 to 4 months was appropriate for baijiu brewing. The results presented in this study may enhance understanding of the impact of storage on daqu quality and, consequently, help to improve it. © 2025 Society of Chemical Industry.

An annotated checklist of flora of Drass valley (Ladakh), India

In this study, an annotated checklist of the flora of Drass valley, located in the Trans-Himalaya region of Ladakh, is presented. The checklist is based on extensive field explorations conducted from 2019–2022, and records 518 species belonging to 286 genera and 66 families from the study area. These include 464 dicot, 48 monocot, and 6 gymnosperm species. Asteraceae contributed the highest number of 78 species, followed by Fabaceae (32 spp.) and Brassicaceae (31 spp.). Astragalus was the dominant genera with 13 species, followed by Potentilla (10 spp.) and Corydalis (9 spp.). Herbs were the most prevalent growthform (442 spp., 85.33%), followed by subshrubs (33 spp., 6.37%), shrubs (26 spp., 5.02%), trees (15 spp., 2.9%) and climbers with only two species (0.39%). Perennials were predominant contributing 390 species, followed by annuals (98 spp.) and biennials (30 spp.). Habitat-wise, the steppe grasslands harbour the highest number of 183 species, followed by agri-fields (151 spp.), and alpine meadows (138 spp.). Our results reveal that this coldspot, comprising just 0.25% area of the entire Ladakh, harbours about half of the total floristic diversity known from this Trans-Himalayan region. Looking ahead, the present study will form scientific baseline for undertaking advanced research studies in the region, and guide formulation of policy and management strategies towards conservation and sustainable use of the plant resources in this second coldest human-inhabited area of the world.

Analysis of the Synergistic Effect of Endophytic Bacteria and Metabolites on Yield in Soybean Roots Under Biochar with Nitrogen Fertilization

The appropriate application of nitrogen fertilizers and biochar to the soil is beneficial for soybean growth, and a combination of biochar and nitrogen can improve low-nitrogen fertilizer utilization efficiency. However, the effect of the combination of biochar and nitrogen fertilizer on soybean roots is still unclear. Therefore, in this study, we investigate the changes in endophytic bacterial communities and metabolites in soybean roots under different combinations of biochar and nitrogen fertilizer treatments by setting different fertilization levels and using high-throughput sequencing and non-targeted metabolomics techniques. The results showed that applying 20 t/ha of biochar and 180 kg/ha of nitrogen fertilizer (C2N1) resulted in the highest soybean yield. By studying the endophytic bacterial community in soybean roots, it was observed that the dominant phyla were Proteobacteria, Bacteroidota, and Actinobacteriota, and the dominant genera were Bradyrhizobium, Streptomyces, and Rhizobacter. Moreover, a metabolic pathway analysis revealed that glycosylphosphatidylinositol (GPI)-anchor biosynthesis was the most significant metabolic pathway in the C0N1 vs. C0N0 comparison group, and glycerophospholipid metabolism was the most significant metabolic pathway in the C2N1 vs. C1N1 comparison group; they were both associated with regulatory mechanisms such as plant growth promotion and nutrient cycling. Structural equation modeling indicates that both endophytic bacteria and metabolites have a significant positive impact on yield. Bradyrhizobium and Rhizobium are observable variables with significant positive effects on endophytic bacteria, while Phe-Thr and 7-allyloxycoumarin are observable variables with significant positive effects on metabolites. Endophytic bacteria not only have a direct impact on crop yield, but also indirectly affect crop yield through their effects on metabolites. This study has important scientific value and guiding significance for improving soybean yields.

Microbiological effect of topically applied Weissella cibaria on equine pastern dermatitis.

Equine pastern dermatitis (EPD) is a multifactorial disease with a change in the skin microbiome. The present study monitored the influence of Weissella cibaria Biocenol™ 4/8 D37 CCM 9015 stabilized on alginite on the skin microbiota of healthy horses and model patients with EPD. Based on clinical signs, EPD lesions were identified as exudative or proliferative forms. A comparison of the initial microbial community based on 16S rRNA amplicon sequencing revealed that there was a statistically significant difference between healthy vs. exudative (R = 0.52, p = 0.003) and exudative vs. proliferative communities (R = 0.78, p = 0.043). The healthy skin microbiota was dominated by the families Corynebacteriaceae (19.7 ± 15.8%) and Staphylococcaceae (15.8 ± 10.7%). Streptococcus (11.7 ± 4.1%) was the dominant genus in the exudative group together with Corynebacterium (11.0 ± 3.8%), while Staphylococcus (15.6 ± 14.5%) dominated the proliferative group. The genus Staphylococcus represented only 0.5% of the exudative skin microbial community, a major difference between EPD-affected lesion types. Upon application, there was a statistically significant shift in community composition in all the groups, including the healthy community; however, the change was the most significant in the exudative community. On average, the genus Weissella represented 80.0 ± 13.3% of the exudative and 49.0 ± 30.0% of the proliferative bacterial community during treatment. One week after the application period, richness and diversity increased and were comparable in all groups. The application of the W. cibaria strain was associated with a significant decrease of the genera Staphylococcus, Moraxella, and Rothia in the proliferative group and with a decrease of Streptococcus and Clostridium in both exudative and proliferative groups. Based on our results, we conclude that a topically applied W. cibaria RIFR, stabilized on alginit, induced potentially beneficial shifts in the composition of the skin microbiota.

Characterization and Correlation Analysis of Bacterial Composition and Physicochemical Quality in High- and Medium-Temperature Daqu from China's Binzhou Region.

To investigate the bacterial community structure and physicochemical characteristics of different types of Daqu in the Binzhou region, this study employed traditional pure culture methods, high-throughput sequencing technology, and conventional physicochemical assays for analysis. The research results indicate that Enterococcus faecium and Bacillus licheniformis emerged as the main LAB and Bacillus species in Daqu from Binzhou region, respectively. In addition, high-throughput sequencing revealed significant differences in bacterial community structure between the two types of Daqu (P < 0.01). Compostibacillus and Sebaldella were identified as the biomarkers and potential key strains of high- and medium-temperature Daqu, respectively, and high-temperature Daqu demonstrated higher microbial complexity and stability than medium-temperature Daqu. Physicochemical assays demonstrated that the a* value, Daqu skin hardness, Daqu core hardness, density, starch content, and aminophenol content being significantly higher in high-temperature Daqu (P < 0.05), meanwhile, the L* value, water activity, water content, protein content, liquefaction power, and saccharification power were found to be significantly lower in high-temperature Daqu (P < 0.05). And there was significant association between dominant genera and the physicochemical indexes of Daqu (P = 0.001). It can thus be seen that there were significant differences between the microbial communities and physicochemical indicators of different types of Daqu in the Binzhou region. The results of this study are of great significance for further analyzing the differences between different types of Daqu and improving their quality.