Microbial Influence Research Articles

Microbiome-producing SCFAs are associated with preterm birth via trophoblast function modulation.

Preterm birth (PTB) is a leading cause of infant mortality and long-term health issues, affecting millions of families worldwide. Despite its prevalence, the exact causes of PTB remain unclear. Our study reveals that certain bacteria and their metabolic byproducts in the cervicovaginal environment, specifically short-chain fatty acids (SCFAs), are linked to the risk of preterm birth. By analyzing samples from pregnant women, we found that an imbalance in the vaginal microbiota and increased levels of SCFAs are associated with changes in cells that can lead to early labor. This research provides new insights into how the microbiome influences pregnancy outcomes and highlights potential biomarkers for predicting preterm birth. Understanding these microbial influences could lead to innovative strategies for early diagnosis and prevention, ultimately improving maternal and infant health.

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.

A-001 The Postprandial Levels of the Metabolites in the Metaorganismal Trimethylamine N-Oxide (TMAO) Pathway are Altered in A Diet-, Microbe-, and Sex-Specific Manner

Abstract Background Cardiovascular disease (CVD) remains the leading cause of death in developed countries. Elevated levels of the gut-microbe-associated metabolite trimethylamine-N-oxide (TMAO) have been associated with increased risk for CVD mortality in many large independent studies. In fact, large laboratory corporations such as Labcorp and Quest Diagnostic now offer TMAO diagnostic tests for the assessment of CVD risk and as a marker for disease-associated dysbiosis, using samples obtained from fasting patients. Although the strong association between TMAO levels and CVD risk has been established in fasting blood samples, here we are investigating the potential for a single meal to dynamically alter TMAO-related metabolites based on sex, diverse dietary substrates, and microbial influences. Methods 35 healthy participants were randomized to one of four study groups with approximately 8-9 subjects in each arm. Half of the participants were randomly assigned to receive a three-day broad spectrum antibiotic regimen (ciprofloxacin, metronidazole, and vancomycin) while the others received no antibiotics. These two groups were further subdivided into a group consuming a highly processed meal (originating from local fast food restaurants) or alternatively a whole food meal (containing a variety of fruits, vegetables, and healthy fiber). Blood samples were taken at baseline (after an overnight fast), and then postprandially at 15 minutes, 30 minutes, 1 hour, 2 hours, 4 hours, and 6 hours after meal ingestion. Targeted plasma metabolites were quantified using a stable isotope dilution, liquid chromatography - tandem mass spectrometry (LC-MS/MS) method Results While plasma TMAO levels between food groups did not change significantly within the total cohort, there were clear individualized responses to either highly processed or whole food meals. Separation based on sex showed that TMAO levels were significantly reduced in females at 6 hours but remained steady in males for both food groups. Particularly, in the processed food group, TMAO levels were significantly lower in females than males at the 6-hour time point. Neither of these observations held true for TMAO precursors choline, carnitine, or betaine. However, plasma levels of a dietary precursor for TMAO, γ-butyrobetaine, showed clear diet-microbe-host interactions. For males in the processed food group, plasma γ-butyrobetaine levels were significantly increased in subjects on broad spectrum antibiotics. Conclusions Our results show the postprandial levels of TMAO, and its nutrient precursors dynamically change in a diet-, microbe-, and sex-dependent manner. These findings provide new insights into the postprandial levels of TMAO-related metabolites and may inform precision nutritional approaches in those who could benefit from TMAO-lowering strategies.

Common carp Peptidoglycan Gecognition Protein 2 (CcPGRP2) alleviates gut dysbiosis induced by Aeromonas hydrophila

ObjectivesPeptidoglycan recognition protein 2 (PGRP2) plays a role in regulating immune defense in fish. Our previous studies found that CcPGRP2 helped maintain the integrity of the intestinal mucosa of carp and could bind and agglutinate bacteria when infected with A. hydrophila. However, its effect on the structure of the microbiota has not yet been clarified. Therefore, it is necessary to explore the effect of CcPGRP2 on the intestinal microbiota structure in fish. MethodsIn the present study, common carp were injected with CcPGRP2 protein intraperitoneally and high-throughput sequencing technology was used to study the difference in intestinal microbiota structure. Firstly, the variations in α- and β-diversity of the intestinal microbiota of common carp in control and treatment groups were tested, and the results indicated that intraperitoneal injection of A. hydrophila significantly reduced the microbial α-diversity (within-samples) and β-diversity (between-samples) in common carp gut samples, but CcPGRP2 protein could alleviate these reduction, no matter in the case of simultaneous injection of CcPGRP2 protein and A. hydrophila or a intermitted injection with first injection of CcPGRP2 and then A. hydrophila after 6 h. Subsequently, the intestinal microbiota structures of common carp on various taxonomic levels were interrogated under the treatments. ResultsThe data revealed that the abundance of intestinal pathogen Aeromonas was reduced when CcPGRP2 was injected in the common carp, and the alleviation effect was better when CcPGRP2 was injected with A. hydrophila at the same time, implying the function of CcPGRP2 in inhibiting intestinal dysbiosis. Moreover, the functional prediction demonstrated the possible physiological shifts and the influences of microbes on the environment after the common carp is injected with A. hydrophila and CcPGRP2. Finally, the bacterial interaction patterns results showed that the groups injected with A. hydrophila were diverted away from the control group in terms of clustering relationship, while the injection of CcPGRP2 could reverse the effect of A. hydrophila and keep the microbial structure closer to that of the control group; meanwhile, the effect of simultaneous injection of A. hydrophila and CcPGRP2 was better than that of intermitted injections. ConclusionsAll the results in this study suggest that the CcPGRP2 could alleviate the internal dysbiosis under pathogen infection, which will provide a foundation for disease resistance breeding.

A critical review of microbial influence upon the severity of radiation-induced oral mucositis in head and neck squamous cell carcinoma, and its potential impact on future management.

A critical review of microbial influence upon the severity of radiation-induced oral mucositis in head and neck squamous cell carcinoma, and its potential impact on future management.

Elucidating core microbiota in yellow wine (Huangjiu) through flavor-oriented synthesis and construction of microbial communities

Huangjiu, a traditional Chinese alcoholic beverage with a history spanning thousands of years, holds significant cultural and economic value in China. Despite its importance, the complexity of Huangjiu fermentation and the intricate interactions within its microbial community remain underexplored. This study addresses this gap by identifying the core volatile organic compounds (VOCs) and key microorganisms that define the flavor profile of Huangjiu. We employed HS-SPME-GC–MS along with aroma reconstitution and omission experiments to identify core VOCs, including Isobutanol, Isoamyl alcohol, β-Phenylethanol, and others. Metagenomic sequencing combined with QPCR was used to analyze microbial communities, revealing the temporal and spatial dynamics during fermentation. A synthetic microbial community model was constructed using the core microbes identified: Saccharomyces cerevisiae, Lactobacillus brevis, Saccharopolyspora rectivirgula, Bacillus subtilis, Leuconostoc citreum, Lactobacillus plantarum, Lactobacillus curvatus, Lactobacillus casei, and Aspergillus oryzae. This model successfully replicated Huangjiu’s core VOCs and sensory characteristics, increased alcohol content, and reduced acidity. Our study contributes valuable insights into the microbial influences on Huangjiu quality, paving the way for its enhanced production and providing a foundation for future research in fermented beverages.

Investigation of unsteady Buongiorno nanofluid in a slanted thermally radiated revolving channel under upstream microbial movement in the absence of chemical reaction

Analysis of Buongiorno nanofluid in a thermally radiated channel in the occurrence of microbes is an enrich research motive. Thermal radiations, dissipation energy, transient effects and upstream microbial acceleration potentially alter the performance of Buongiorno nanofluid. This is a two phase nanofluid model which accommodates the thermophoretic and Brownian movement of the particles along with other integrated physical quantities. Hence, the current research aims to conduct the study of Buongiorno nanofluid in a slanted thermally radiated micro channel in the presence of aforementioned physical phenomenon. The outcomes of the model achieved numerically and discussed deeply. It is investigated that the unsteady and channel revolving parameters enhances the nanofluid movement while adjusting the channel at different inclination also favors the velocity. The velocity G(η) upsurges for larger rotation of the channel while it drops for more transient fluid. Further, the thermophoretic and particles deposition boosts the thermal performance of the setup while thermal radiations depreciated the efficiency. The Schmidt effects in the range of 1.0–7.0 highly contributes in the improvement of mass transport. Moreover, density motile of microbes improved for Lewis and transient effects while Peclet effects are examined excellent to control the microbial influence.

Lupus and inflammatory bowel disease share a common set of microbiome features distinct from other autoimmune disorders

ObjectivesThis study aims to elucidate the microbial signatures associated with autoimmune diseases, particularly systemic lupus erythematosus (SLE) and inflammatory bowel disease (IBD), compared with colorectal cancer (CRC), to identify unique...

The role of organic matter in Brazilian Pre‐Salt carbonates

AbstractDiverse types of organic matter morphology were identified in Brazilian Pre‐salt carbonates. Stromatolites and laminated facies contain organic layers, filaments and rounded features inside calcite structures, as shrubs and spherulites. Analyses with optical and fluorescent microscopy, scanning electron microscopy with energy‐dispersive X‐ray spectroscopy, and ion mass spectrometry indicate the presence of organic compounds in thin sections. Fluorescent microscopy shows a high signal for organic portions in the thin section, mainly inside calcite structures and within the matrix. Scanning electron microscopy with energy‐dispersive X‐ray spectroscopy elemental mapping indicates the presence of carbon in the stromatolite facies, associated either with calcium and oxygen, indicating carbonate, or isolated from other elements, representing carbon content in the samples. The presence of organic matter along and inside calcite structures indicate a strong microbial influence in Brazilian Pre‐Salt carbonates precipitation. The purpose of this research is to show that the presence of organic matter is connected to the process of carbonate precipitation and/or dissolution. The occurrence of these organic compounds in distinguishing facies raises the discussion of biotic versus abiotic genesis of the Pre‐salt lacustrine reservoirs.

Soil microbial influences over coexistence potential in multispecies plant communities in a subtropical forest.

Soil microbes have long been recognized to substantially affect the coexistence of pairwise plant species across terrestrial ecosystems. However, projecting their impacts on the coexistence of multispecies plant systems remains a pressing challenge. To address this challenge, we conducted a greenhouse experiment with 540 seedlings of five tree species in a subtropical forest in China and evaluated microbial effects on multispecies coexistence using the structural method, which quantifies how the structure of species interactions influences the likelihood for multiple species to persist. Specifically, we grew seedlings alone or with competitors in different microbial contexts and fitted individual biomass to a population dynamic model to calculate intra- and interspecific interaction strength with and without soil microbes. We then used these interaction structures to calculate two metrics of multispecies coexistence, structural niche differences (which promote coexistence) and structural fitness differences (which drive exclusion), for all possible communities comprising two to five plant species. We found that soil microbes generally increased both the structural niche and fitness differences across all communities, with a much stronger effect on structural fitness differences. A further examination of functional traits between plant species pairs found that trait differences are stronger predictors of structural niche differences than of structural fitness differences, and that soil microbes have the potential to change trait-mediated plant interactions. Our findings underscore that soil microbes strongly influence the coexistence of multispecies plant systems, and also add to the experimental evidence that the influence is more on fitness differences rather than on niche differences.

Soil Microbial Communities and Wine Terroir: Research Gaps and Data Needs.

Microbes found in soil can have a significant impact on the taste and quality of wine, also referred to as wine terroir. To date, wine terroir has been thought to be associated with the physical and chemical characteristics of the soil. However, there is a fragmented understanding of the contribution of vineyard soil microbes to wine terroir. Additionally, vineyards can play an important role in carbon sequestration since the promotion of healthy soil and microbial communities directly impacts greenhouse gas emissions in the atmosphere. We review 24 studies that explore the role of soil microbial communities in vineyards and their influence on grapevine health, grape composition, and wine quality. Studies spanning 2015 to 2018 laid a foundation by exploring soil microbial biogeography in vineyards, vineyard management effects, and the reservoir function of soil microbes for grape-associated microbiota. On the other hand, studies spanning 2019 to 2023 appear to have a more specific and targeted approach, delving into the relationships between soil microbes and grape metabolites, the microbial distribution at different soil depths, and microbial influences on wine flavor and composition. Next, we identify research gaps and make recommendations for future work. Specifically, most of the studies utilize targeted sequencing (16S, 26S, ITS), which only reveals community composition. Utilizing high-throughput omics approaches such as shotgun sequencing (to infer function) and transcriptomics (for actual function) is vital to determining the specific mechanisms by which soil microbes influence grape chemistry. Going forward, understanding the long-term effects of vineyard management practices and climate change on soil microbiology, grapevine trunk diseases, and the role of bacteriophages in vineyard soil and wine-making would be a fruitful investigation. Overall, the studies presented shed light on the importance of soil microbiomes and their interactions with grapevines in shaping wine production. However, there are still many aspects of this complex ecosystem that require further exploration and understanding to support sustainable viticulture and enhance wine quality.

Effects of different Mg/Ca molar ratio on the formation of carbonate minerals in microbially induced carbonate precipitation (MICP) process

Traditional MICP technology has been extensively applied to improve soil properties and solidify heavy metal contaminated soil. However, the traditional product performance of calcite is far less than that of huntite, dolomite, and other carbonate minerals. Therefore, the soil strength and environmental safety after curing cannot reach the safety index. This study has examined the distribution of carbonate minerals induced by microorganisms under different Mg/Ca ratio. Compared with the sample with 0 Mg/Ca content, the unconfined compressive strength (UCS) can be increased by 1–5 times by increasing the content. By X-ray diffraction (XRD) and thermogravimetric analysis (TGA), the contents of different carbonate minerals under different Mg/Ca content were determined semi-quantitatively. The microscopic results have also shown that the introduction of microorganisms can provide nucleation sites for the synthesis of dolomite and huntite. MICP experiment coupled with Quantum ESPRESSO calculations revealed the mechanism of microbial influence on the formation of carbonate minerals under different Mg/Ca conditions through first principles calculations and nucleation kinetics. These findings advance our understanding of the reaction mechanisms and pathways of biogenic precipitation of carbonate minerals, and provide insights into the artificial quantitative synthesis of dolomite.

Diversity and potential functional role of phyllosphere-associated actinomycetota isolated from cupuassu (Theobroma grandiflorum) leaves: implications for ecosystem dynamics and plant defense strategies.

Exploring the intricate relationships between plants and their resident microorganisms is crucial not only for developing new methods to improve disease resistance and crop yields but also for understanding their co-evolutionary dynamics. Our research delves into the role of the phyllosphere-associated microbiome, especially Actinomycetota species, in enhancing pathogen resistance in Theobroma grandiflorum, or cupuassu, an agriculturally valuable Amazonian fruit tree vulnerable to witches' broom disease caused by Moniliophthora perniciosa. While breeding resistant cupuassu genotypes is a possible solution, the capacity of the Actinomycetota phylum to produce beneficial metabolites offers an alternative approach yet to be explored in this context. Utilizing advanced long-read sequencing and metagenomic analysis, we examined Actinomycetota from the phyllosphere of a disease-resistant cupuassu genotype, identifying 11 Metagenome-Assembled Genomes across eight genera. Our comparative genomic analysis uncovered 54 Biosynthetic Gene Clusters related to antitumor, antimicrobial, and plant growth-promoting activities, alongside cutinases and type VII secretion system-associated genes. These results indicate the potential of phyllosphere-associated Actinomycetota in cupuassu for inducing resistance or antagonism against pathogens. By integrating our genomic discoveries with the existing knowledge of cupuassu's defense mechanisms, we developed a model hypothesizing the synergistic or antagonistic interactions between plant and identified Actinomycetota during plant-pathogen interactions. This model offers a framework for understanding the intricate dynamics of microbial influence on plant health. In conclusion, this study underscores the significance of the phyllosphere microbiome, particularly Actinomycetota, in the broader context of harnessing microbial interactions for plant health. These findings offer valuable insights for enhancing agricultural productivity and sustainability.

Development of systemic and mucosal immune responses against gut microbiota in early life and implications for the onset of allergies.

The early microbial colonization of human mucosal surfaces is essential for the development of the host immune system. Already during pregnancy, the unborn child is prepared for the postnatal influx of commensals and pathogens via maternal antibodies, and after birth this protection is continued with antibodies in breast milk. During this critical window of time, which extends from pregnancy to the first year of life, each encounter with a microorganism can influence children's immune response and can have a lifelong impact on their life. For example, there are numerous links between the development of allergies and an altered gut microbiome. However, the exact mechanisms behind microbial influences, also extending to how viruses influence host-microbe interactions, are incompletely understood. In this review, we address the impact of infants' first microbial encounters, how the immune system develops to interact with gut microbiota, and summarize how an altered immune response could be implied in allergies.

Microbial influence on the larval survival of Japanese eel Anguilla japonica: Antibiotic-mediated alterations and biomarker isolation.

In rearing systems for the Japanese eel Anguilla japonica, although it is assumed that microorganisms influence larval survival and mortality, particularly during the early stages of growth, the effects of bacterial communities on larval survival have yet to be sufficiently determined. In this study, we compared the bacterial communities associated with larval survival at three stages of eel growth. To artificially alter bacterial communities and assess larval survival, eel larvae were treated with 11 types of antibiotic, and larval survival and bacterial characteristics were compared between the antibiotic-treated and antibiotic-free control groups. Throughout the three growth stages, eels treated with four antibiotics (polymyxin B, tetracycline, novobiocin, and erythromycin) had survival rates higher than those in the control groups. The bacterial communities of surviving larvae in the control and antibiotic groups and dead larvae in the control groups were subsequently analyzed using 16S rRNA gene amplicon sequencing. PERMANOVA analysis indicated that these three larval groups were characterized by significantly different bacterial communities. We identified 14 biomarker amplicon sequence variants (ASVs) of bacterial genera such as Oceanobacter, Alcanivorax, Marinobacter, Roseibium, and Sneathiella that were enriched in surviving larvae in the antibiotic treatment groups. In contrast, all four biomarker ASVs enriched in dead larvae of the control groups were from bacteria in the genus Vibrio. Moreover, 52 bacterial strains corresponding to nine biomarkers were isolated using a culture method. To the best of our knowledge, this is the first study to evaluate the bacterial communities associated with the survival and mortality of larvae in during the early stages of Japanese eel growth and to isolate biomarker bacterial strains. These findings will provide valuable insights for enhancing larval survival in the eel larval rearing systems from a microbiological perspective.

Indigenous microbial influence on REE enrichment and fractionation in South China weathering crusts: Insights from experimental simulations

The activity of microorganism plays an important role on the enrichment, migration and fractionation of rare earth elements (REEs) in the supergene environment. To investigate the characteristics of indigenous microorganisms on the enrichment and fractionation of REEs, we studied the adsorption efficiencies of REEs by 30 indigenous microbial strains that were isolated and cultured from the weathering profile of a regolith-hosted REE deposit in South China. Most microbial strains exhibited high adsorption efficiencies for REEs, ranging from 2.3 to 42.9 mg g−1. Notably, the taxonomic classification of microorganisms significantly influenced the adsorption selectivity. Gram-positive bacteria exhibited a pronounced enrichment of the heavy REEs, while gram-negative bacteria showed no obvious adsorption preference. The tetrad effects were observed in REE adsorption patterns of gram-negative bacteria and fungi; however, fungi demonstrated a much higher affinity for light and medium REEs. Chemically modified microbial cells were employed to investigate the adsorption mechanism, revealing that distinct functional groups of microbial cells corresponded to the adsorption preference of microorganisms towards REE. Carboxyl and phosphate groups contributed to a relatively high adsorption capacity for light REEs and heavy REEs, respectively. The findings of our study suggest that the distinct composition of microbial groups may exert a significant influence on the biogeochemical cycle of REE in weathering profiles.

Microbial influence in Spanish bentonite slurry microcosms: Unveiling a-year long geochemical evolution and early-stage copper corrosion related to nuclear waste repositories

The deep geological repository (DGR) concept consists of storing radioactive waste in metal canisters, surrounded by compacted bentonite, and placed deeply into a geological formation. Here, bentonite slurry microcosms with copper canisters, inoculated with bacterial consortium and amended with acetate, lactate and sulfate were set up to investigate their geochemical evolution over a year under anoxic conditions. The impact of microbial communities on the corrosion of the copper canisters in an early-stage (45 days) was also assessed. The amended bacterial consortium and electron donors/acceptor accelerated the microbial activity, while the heat-shocked process had a retarding effect. The microbial communities partially oxidize lactate to acetate, which is subsequently consumed when the lactate is depleted. Early-stage microbial communities showed that the bacterial consortium reduced microbial diversity with Pseudomonas and Stenotrophomonas dominating the community. However, sulfate-reducing bacteria such as Desulfocurvibacter, Anaerosolibacter, and Desulfosporosinus were enriched coupling oxidation of lactate/acetate with reduction of sulfates. The generated biogenic sulfides, which could mediate the conversion of copper oxides (possibly formed by trapped oxygen molecules on the bentonite or driven by the reduction of H2O) to copper sulfide (Cu2S), were identified by X-ray photoelectron spectroscopy (XPS). Overall, these findings shed light on the ideal geochemical conditions that would affect the stability of DGR barriers, emphasizing the impact of the SRB on the corrosion of the metal canisters, the gas generation, and the interaction with components of the bentonite.

The Human Microbiome-A Physiologic Perspective.

The human microbiome consists of the microorganisms associated with the body, such as bacteria, fungi, archaea, protozoa, and viruses, along with their gene content and products. These microbes are abundant in the digestive, respiratory, renal/urinary, and reproductive systems. While microbes found in other organs/tissues are often associated with diseases, some reports suggest their presence even in healthy individuals. Lack of microbial colonization does not indicate a lack of microbial influence, as their metabolites can affect distant locations through circulation. In a healthy state, these microbes maintain a mutualistic relationship and help shape the host's physiological functions. Unlike the host's genetic content, microbial gene content and expression are dynamic and influenced by factors such as ethnicity, genetic background, sex, age, lifestyle/diet, and psychological/physical conditions. Therefore, defining a healthy microbiome becomes challenging as it is context dependent and can vary over time for an individual. Although differences in microbial composition have been observed in various diseases, these changes may reflect host alterations rather than causing the disease itself. As the field is evolving, there is increased emphasis on understanding when changes in the microbiome are an important component of pathogenesis rather than the consequence of a disease state. This article focuses on the microbial component in the digestive and respiratory tracts-the primary sites colonized by microorganisms-and the physiological functions of microbial metabolites in these systems. It also discusses their physiological functions in the central nervous and cardiovascular systems, which have no microorganism colonization under healthy conditions based on human studies. © 2024 American Physiological Society. Compr Physiol 14:5491-5519, 2024.

Exploring Microbial Influence on Flavor Development during Coffee Processing in Humid Subtropical Climate through Metagenetic-Metabolomics Analysis.

Research into microbial interactions during coffee processing is essential for developing new methods that adapt to climate change and improve flavor, thus enhancing the resilience and quality of global coffee production. This study aimed to investigate how microbial communities interact and contribute to flavor development in coffee processing within humid subtropical climates. Employing Illumina sequencing for microbial dynamics analysis, and high-performance liquid chromatography (HPLC) integrated with gas chromatography-mass spectrometry (GC-MS) for metabolite assessment, the study revealed intricate microbial diversity and associated metabolic activities. Throughout the fermentation process, dominant microbial species included Enterobacter, Erwinia, Kluyvera, and Pantoea from the prokaryotic group, and Fusarium, Cladosporium, Kurtzmaniella, Leptosphaerulina, Neonectria, and Penicillium from the eukaryotic group. The key metabolites identified were ethanol, and lactic, acetic, and citric acids. Notably, the bacterial community plays a crucial role in flavor development by utilizing metabolic versatility to produce esters and alcohols, while plant-derived metabolites such as caffeine and linalool remain stable throughout the fermentation process. The undirected network analysis revealed 321 interactions among microbial species and key substances during the fermentation process, with Enterobacter, Kluyvera, and Serratia showing strong connections with sugar and various volatile compounds, such as hexanal, benzaldehyde, 3-methylbenzaldehyde, 2-butenal, and 4-heptenal. These interactions, including inhibitory effects by Fusarium and Cladosporium, suggest microbial adaptability to subtropical conditions, potentially influencing fermentation and coffee quality. The sensory analysis showed that the final beverage obtained a score of 80.83 ± 0.39, being classified as a specialty coffee by the Specialty Coffee Association (SCA) metrics. Nonetheless, further enhancements in acidity, body, and aftertaste could lead to a more balanced flavor profile. The findings of this research hold substantial implications for the coffee industry in humid subtropical regions, offering potential strategies to enhance flavor quality and consistency through controlled fermentation practices. Furthermore, this study contributes to the broader understanding of how microbial ecology interplays with environmental factors to influence food and beverage fermentation, a topic of growing interest in the context of climate change and sustainable agriculture.

Assessing the effects of live yeast supplementation to diets containing high starch of dairy cows on rumen fermentation and methane production in vitro

Abstract This study was conducted to evaluate the effects of live Saccharomyces cerevisiae yeast (LY) supplementation on high-starch diets for dairy cows. Using a 2 × 2 factorial design, four treatment groups were examined: adequate starch without LY (AS-control), AS with LY (AS-LY), high starch without LY (HS-control), and HS with LY (HS-LY). LY was added at 2.9 × 106 CFU/200 mg DM or without yeast. In vitro gas and methane (CH4) production, organic matter (OM) digestibility, rumen fermentation, and metabolizable energy (ME) were analyzed. The Hohenheim Gas Test apparatus was used, and total gas volumes were measured at various incubation hours. Results showed no significant effects of LY or dietary starch ratio on gas kinetics, total gas, or CH4 production. Similarly, OM digestibility, fermentation kinetics, and ME were unaffected. In conclusion, LY supplementation did not alter in vitro gas, CH4 production, OM digestibility, rumen fermentation, or ME. Further research could investigate the underlying mechanisms, such as rumen microbial population influences.