Search Results (234)

To explore an industrial fermentation approach for traditional mung bean sour pulp, this study isolated core microorganisms including lactic acid bacteria and yeasts from naturally fermented samples and constructed a synthetic microbial community. The optimized community consisted of Lactiplantibacillus pentosus, Lactococcus garvieae, and Cyberlindnera jadinii at a ratio of 7:3:0.1 and was used to ferment cooked mung bean pulp with a material-to-water ratio of 1:8 and 1% sucrose addition. Under these conditions, the final product exhibited significantly higher levels of protein (4.55 mg/mL), flavonoids (0.10 mg/mL), polyphenols (0.11 mg/mL), and vitamin C (7.75 μg/mL) than traditionally fermented mung bean sour pulp, along with enhanced antioxidant activity. The analysis of organic acids, free amino acids, and volatile compounds showed that lactic acid was the main acid component, the bitter amino acid content was reduced, the volatile flavor compounds were more abundant, and the level of harmful compound dimethyl sulfide was significantly decreased. These results indicate that fermentation using a synthetic microbial community effectively improved the nutritional quality, flavor, and safety of mung bean sour pulp. Full article

Garlic (Allium sativum L.) is extensively recognized for its health-promoting effects and functional attributes, including antibacterial and anti-inflammatory activities. Additionally, the derived product of the industrial maturation process, known as black garlic, is famous for its functional properties. The novelty of the present work is to characterize the functional properties of domestically produced black garlic. In fact, this study examines the domestic maturation of fresh garlic bulbs into black garlic of two Italian varieties, focusing on microbial growth, antimicrobial properties, prebiotic activity, volatile organic compounds, mechanical resistance, brown intensity, pH, and Aw. Results show that domestic processes are microbiologically and chemically safe and generate black garlic products with functional attributes such as prebiotic activity and the presence of health-related bioactive compounds, also developing superior technological performance. These findings enhance the understanding of black garlic culinary practices, leveraging gastronomic preparations for the development of healthier and safer food products. Full article

This study provides a comprehensive analysis of the microbial dynamics involved in the fermentation process of traditional Musalais wine, an intangible cultural heritage of Xinjiang. Utilizing metagenomic sequencing, we identified 2894 microbial species, of which 494 persisted throughout the fermentation process. Saccharomyces cerevisiae was the dominant species, with its prevalence increasing from 97.35% in the early phase to 99.38% in the mid phase, before slightly decreasing to 98.79% in the late phase. Additionally, 24 non-Saccharomyces yeast species, including Hanseniaspora uvarum, Lachancea thermotolerans, and Torulaspora delbrueckii, were detected. Common species associated with other fermented foods, including Wickerhamomyces anomalus, Kluyveromyces marxianus, Saccharomyces eubayanus, and Zygosaccharomyces parabailii, were also identified. Notably, species not previously used in food fermentation, such as Saccharomyces jurei, Sodiomyces alkalinus, Vanrija pseudolonga, and Moesziomyces antarcticus, were also identified in this study. Furthermore, the Kyoto Encyclopedia of Genes and Genomes (KO) and Gene Ontology (GO) revealed notable variations in metabolic pathways and enriched functional genes. In addition, a total of 82 volatile compounds were detected in the final product, with higher alcohols (60.12%), esters (37.80%), and organic acids (1.80%) being the most prevalent. These results offer important insights into microbial interactions and their influence on Musalais wine quality, laying the groundwork for optimizing the fermentation process. Full article

A VOC-contaminated shallow aquifer in an industrial site was investigated to evaluate its potential for natural attenuation. The shallow groundwater aquifer beneath the industrial site has been contaminated by dissolved volatile organic compounds (VOCs) such as trichloroethylene (TCE), cis-1,2-dichloroethylene (cis-DCE), and vinyl chloride (VC) for more than three decades. Monitoring and investigation were implemented during 2011–2024, aiming to propose future groundwater aquifer management strategies. This study included groundwater borehole investigation, well installation monitoring, hydraulic head measurements, slug tests, groundwater samplings, and microbial analyses. Microbial investigations identified the predominant group of microorganisms of Proteobacteria, indicating biodegradation potential, as demonstrated by the presence of cis-DCE and VC. BIOSCREEN was used to evaluate the process of natural attenuation, incorporating site-specific parameters. A two-layer groundwater flow model was developed using MODFLOW with hydraulic conductivities obtained from slug tests. The site has an average hydraulic head of 259.6 m amsl with a hydraulic gradient of 0.026, resulting in an average groundwater flow velocity of 11 m/y. Hydraulic conductivities were estimated during model calibration using the PEST pilot point technique. A reactive transport model, RT3D, was used to simulate dissolved TCE transport over 30 years, which can undergo sorption as well as biodegradation. Model calibration demonstrated a satisfactory fit between observed and simulated groundwater heads with a root mean square error of 0.08 m and a correlation coefficient (r) between measured and simulated heads of 0.81, confirming the validity of the hydraulic conductivity distribution. The TCE plume continuously degraded and gradually migrated southward, generating a cis-DCE plume. The concentrations in both plumes decreased toward the end of the simulation period at Source 1 (located upstream), while BIOSCREEN results confirmed ongoing natural attenuation primarily by biodegradation. The integrated MODFLOW-RT3D-BIOSCREEN approach effectively evaluated VOC attenuation and plume migration. However, future remediation strategies should consider enhanced bioremediation to accelerate contaminant degradation at Source 2 and ensure long-term groundwater quality. Full article

Sweet cherry (Prunus avium L.), as a high-economic-value fruit with both nutritional and health functions, faces severely constrained plant growth due to underdeveloped root systems and suboptimal orchard site conditions. Plant growth-promoting rhizobacteria (PGPR) demonstrate application potential in regulating plant development and improving soil structure through the release of volatile organic compounds (VOCs). This study systematically evaluated the effects of VOCs from three PGPR strains—Pantoea ananatis D1-28, Burkholderia sp. D4-24, and Burkholderia territorii D4-36—on cherry root development and rhizosphere microbial communities. The results indicate that when D1-28 and D4-24 strains were at 10³ cfu·mL⁻¹ and D4-36 was at 10⁵ CFU·mL⁻¹, their VOCs exhibited optimal growth-promoting effects. Compared with the control group, significant improvements were observed in cherry seedling parameters, including plant height, total biomass, root length, root surface area, and root volume. The VOCs from these strains synergistically promoted plant growth by regulating auxin synthesis pathways in cherry roots while enhancing the relative abundance of beneficial rhizosphere microorganisms. This study establishes the strain-concentration–effect relationship, providing a theoretical foundation to optimize soil microbial environments and promote cherry root development using PGPR. Full article

Sixteen long-ripened, high-quality Cabrales cheeses from independent producers underwent a comprehensive biochemical and microbiological characterisation. Significant variations in total microbial counts and specific microbial groups were observed among the cheeses. A metataxonomic analysis identified 249 prokaryotic amplicon sequence variants (ASVs) and 99 eukaryotic ASVs, respectively, which were classified into 52 prokaryotic and 43 eukaryotic species. The predominant species included bacteria of the genera Tetragenococcus, Lactococcus (of which Lactococcus lactis was used as a starter), and Staphylococcus, followed by Brevibacterium and Corynebacterium species. The starter mould Penicillium roqueforti was highly abundant in all cheeses; Debaryomyces hansenii, Geotrichum candidum, and Kluyveromyces spp. constituted the subdominant fungal populations. Glutamic acid (≈20 mg g⁻¹) was the most abundant free amino acid in all samples, followed by lysine, leucine, and valine (≈10–13 mg g⁻¹). Moderate-to-high amounts of the biogenic amines tyramine and ornithine were detected. A large variation between cheeses of the main organic acids (lactic, acetic, or butyric) was detected. Differences between samples were also observed for the majority volatile compounds, which included organic acids, alcohols, esters, and ketones. Positive and negative correlations between bacterial and fungal species were detected, as well as between microbial populations and key biochemical markers. Among the latter, Tetragenococcus halophilus correlated positively with ethyl caprylate and hexanoic acid, and Loigolactobacillus rennini correlated positively with γ-aminobutyric acid. Conversely, Staphylococcus equorum showed a strong negative correlation with ethyl caprylate and capric acid. These microbial and biochemical insights enabled us to propose a microbiota-based starter culture comprising prokaryotic and eukaryotic components to enhance Cabrales cheese quality. Full article

Climate change poses significant risks to food security and contributes to widespread soil degradation. Effective strategies are urgently needed to mitigate its impacts and ensure stable crop production and food quality. Biochar has shown strong potential to reduce greenhouse gas emissions, enhance carbon sequestration, and immobilize soil contaminants such as heavy metals and organic pollutants. These benefits can lead to increased crop yields, improved nutritional quality, and reduced uptake of harmful substances by plants. This review summarizes the possible mechanisms through which biochar influences the biochar–soil–plant interface, aiming to provide a comprehensive understanding of its multifaceted roles. Although positive effects of biochar on crop production are frequently reported, neutral or even negative outcomes have also been observed. Such adverse effects may be attributed to the presence of volatile organic compounds, free radicals, or heavy metals in certain biochars that inhibit plant growth. Additionally, biochar application has been found to reduce plant infections caused by pathogens, likely due to the presence of organic compounds that act as microbial inhibitors. A deeper understanding of the mechanisms by which biochar affects plant growth is essential for its effective use as a tool to combat climate change and enhance food security. Full article

Kimchi, a traditional fermented product made primarily with Chinese cabbage, develops its characteristic flavor through microbial activity and a variety of ingredients. This study explores the incorporation of sea fennel (Crithmum maritimum L.), a halophytic plant rich in bioactive compounds and known for its distinctive aroma, into kimchi. Two fermentation methods were compared: spontaneous fermentation and fermentation using a defined starter culture of four lactic acid bacteria strains. Fermentation was conducted at 4 °C for 26 days, with samples monitored for up to 150 days. Parameters analyzed included pH, titratable acidity, microbial counts, organic acid concentrations, volatile organic compounds (VOCs), and sensory attributes. In the early stages, notable differences in acidity, microbial populations, and VOCs were observed between the two methods, but these differences diminished over time. Sensory analysis indicated similar overall characteristics for both prototypes, although the sea fennel’s aroma and fibrous texture remained perceptible at day 150. VOCs analysis revealed that the fermentation time significantly affected the composition of key aroma compounds, contributing to the final sensory profile. Sea fennel played a key role in shaping the VOC profile and imparting a distinctive aromatic quality. Both fermentation methods led to similar enhancements in flavor and product quality. These findings support the use of sea fennel as an aromatic ingredient in fermented vegetables and highlight the importance of fermentation optimization. Full article

With the sustainable increase in agricultural productivity, the need for safer, environmentally friendly pesticide alternatives is also growing. Metabolites of microorganisms (bacteria, fungi, actinomycetes) are emerging as potential bioactive compounds for integrated pest and disease management. These compounds comprise amino acids, carbohydrates, lipids, organic acids, phenolics, peptides, alkaloids, polyketides, and volatile organic compounds. The majority of them have insecticidal, fungicidal, and nematicidal activities. In this review, the classifications, biosynthetic pathways, and ecological functions of primary and secondary metabolites produced by microorganisms are discussed, including their mechanisms of action, ranging from competition to systemic acquired resistance in host plants. The article highlights the importance of microbial genera (viz., Bacillus sp., Pseudomonas sp., Trichoderma sp., Streptomyces sp., etc.) in making chemicals and biopesticides for crop defense. We present the possible applications of microbial biosynthesis strategies and synthetic biology tools in bioprocess development, covering recent innovations in formulation, delivery, and pathway engineering to enhance metabolite production. This review emphasizes the significance of microbial metabolites in improving the plant immunity, yield performance, reduction in pesticide application, and the sustainability of an ecological, sustainable, and resilient agricultural system. Full article

This study investigated changes in microbial communities and functional components during the fermentation of traditional Korean grain vinegars collected from various regions as well as the correlations among these components. Microbial community analysis revealed that Lactobacillus acetotolerans was the dominant microorganism, while Acetobacter pasteurianus numbers gradually increased during fermentation, playing a key role in acetic acid production. L. acetotolerans, known to thrive in acidic environments, contributed to increasing the acidity of the vinegar and enhanced its preservative properties. The rise in the levels of organic acids, particularly acetic acid, was influenced by the activity of these microorganisms. Additionally, the production of free amino acids, such as alanine, was influenced by interactions between the fermentation medium and microbial communities, significantly contributing to the vinegar’s sweetness. Volatile flavor compounds exhibited considerable diversity due to changes in microbial communities driven by raw-material differences. In particular, five-grain vinegar (YO) tended to generate more complex and intense flavor compounds, with uniformly elevated levels of aldehydes, acids, and ketones. These findings suggest that raw-material selection and fermentation conditions significantly influence the flavor and functional properties of grain vinegars, providing valuable foundational data for improving vinegar production processes to enhance flavor and functionality. Full article

Pine wilt disease (PWD), caused by the pine wood nematode (PWN, Bursaphelenchus xylophilus), poses a significant threat to global pine forests and calls for the development of innovative management strategies. Microbial control emerges as an effective, cost-efficient, and environmentally sustainable approach to eliminate the damage from PWD. This review consolidates molecular mechanisms in the microbiological control of PWD, which focus on three core strategies: microbial control activity against PWN, biological control of vector insects, and the enhancement of host tree resistance to nematode infections. The review thoroughly evaluates integrated control strategies in which microbial control is used in traditional management practices. Recent studies have pinpointed promising microbial agents for PWN control, such as nematophagous microorganisms, nematicidal metabolites, parasitic fungi that target vector insects, and microbes that boost plant resistance. In particular, the control potential of volatile organic compounds (VOCs) produced by microorganisms against PWN and the enhancement of pine resistance to PWN by microorganisms were emphasized. Moreover, we assessed the challenges and opportunities associated with the field application of microbiological control agents. We emphasized the feasibility of multi-strategy microbial integrated control, which provides a framework for future studies on microbial-based PWD control strategies. Full article

This study investigates the impact of using Lactiplantibacillus plantarum and Saccharomyces cerevisiae, either individually or in co-culture, on the fermentation of rose beverage. We comprehensively analyzed the resulting changes in quality characteristics and volatile compound profiles. Fermentation significantly altered the physicochemical properties, appearance, color, and free amino acid/organic acid content. Both microbial strains significantly increased total polyphenols and flavonoid content, with co-fermentation exhibiting a more pronounced effect compared to single-strain fermentations. Furthermore, the volatile compounds in rose beverages fermented with different microorganisms were characterized by an electronic nose (E-nose) and headspace–solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME/GC-MS). E-nose analysis demonstrated distinct volatile profiles distinguishing the four fermentation samples. HS-SPME/GC-MS identified a total of 245 volatile compounds, among which alcohols constituted the most abundant class. Integrating GC-MS data with odor activity value (OAV ≥ 1) analysis pinpointed 34 key aroma compounds. Partial least-squares discriminant analysis (PLS-DA) based on variable importance in projection (VIP) identified eight key volatile markers: eugenol, phenylethyl alcohol, (E)-3,7-dimethyl-2,6-octadienoic acid, methyleugenol, ethyl octanoate, citronellol, D-citronellol, and 2,4-bis(1,1-dimethylethyl)phenol. These findings provide valuable insights into the microbial influence on rose beverage quality and offer a theoretical basis for optimizing industrial fermentation processes. Full article

Volatile organic compounds (VOC) are major contributors to the burgeoning air pollution issue, predominantly from industrial areas, with well-documented environmental and health risks, which demand efficient and sustainable control policies. This review analyzes the current technological challenges and investigates recent developments in biological treatment technologies for VOC-contaminated off-gases, including biofilters, biotrickling filters, and bioscrubber, as well as emerging technologies, such as bioaugmentation and microbial fuel cells (MFCs). Operational performance, economic feasibility, and adaptability to various industrial applications are assessed, alongside opportunities for integration with other technologies, including energy recovery technologies. Biological systems offer considerable advantages regarding cost savings and lower environmental impacts and enhanced operational flexibility, particularly when combined with innovative materials and microbial optimization techniques. Nevertheless, challenges persist, such as choosing the best treatment settings suited to different VOC streams and addressing biofilm control concerns and scalability. Overall, biological VOC treatments are encouraging sustainable solutions, though continued research into reactor design, microbial dynamics, and MFC-based energetic valorization is essential for broader industrial application. These insights cover advancements and highlight the continuous need for innovative prowess to forge sustainable VOC pollution control. Full article

Roasted carob flour is a sustainable ingredient rich in dietary fiber, polyphenols, and pinitol, offering potential for both food and pharmaceutical applications. However, its high sugar content and the presence of undesirable compounds such as furans present challenges for its use in bread making. This study evaluated the effects of prolonged sourdough fermentation on roasted carob flour, with a focus on microbial dynamics and its functional and technological properties. Carob and carob–wheat sourdoughs were prepared using a mixed starter culture comprising three lactic acid bacteria (Lactiplantibacillus plantarum, Fructilactobacillus sanfranciscensis, and Lactobacillus helveticus) and three yeast species (Saccharomyces cerevisiae, Kazachstania humilis, and Torulaspora delbrueckii). The sourdoughs underwent six consecutive refreshment cycles and were analyzed to determine their pH, microbial and biochemical composition, gassing power, and volatile organic compounds (VOCs). The carob–wheat sourdough exhibited faster acidification and higher lactic acid bacteria (LAB) activity, resulting in a 90–98% reduction in the sugar content, compared to 60% in the carob sourdough. Microbial sequencing revealed that L. plantarum was the dominant species in all samples, while K. humilis and S. cerevisiae were enriched in carob and carob–wheat sourdough, respectively. Both types of sourdough demonstrated effective leavening in bread dough without the addition of commercial yeast. Fermentation also modified the VOC profiles, increasing esters and alcohols while reducing acids, aldehydes, ketones, and furans. While the antioxidant activity showed a slight decline, the pinitol content remained unchanged. These findings suggest that extended sourdough fermentation, supported by multiple refreshments, enhances the baking suitability of roasted carob flour and supports its application as a functional, sustainable ingredient. Full article

Parasitic nematodes play a vital role in soil ecosystems, contributing to natural pest suppression. Among them, slug-parasitic species such as Phasmarhabditis papillosa (Schneider) Andrassy, Oscheius myriophilus (Poinar), and Oscheius onirici Torrini et al. are promising biological control agents against mollusk pests. These nematodes rely on plant-emitted volatile organic compounds (VOCs) for host location, yet their chemotactic responses to specific VOCs remain unclear. This study assessed the responses of P. papillosa, O. myriophilus, and O. onirici to VOCs emitted by potato (S. tuberosum) tubers under varying temperature (18 °C, 22 °C) and concentration conditions (pure compound, 0.03 ppm). The results indicate that octanal was the strongest attractant, particularly for O. myriophilus, while nonanal exhibited species-dependent effects. Hydrocarbons such as undecane and 1,2,4-trimethylbenzene had minimal or repellent effects, whereas 6-methyl-5-hepten-2-one showed moderate attraction. Chemotactic responses were stronger at 18 °C, and attraction increased with higher VOC concentrations, suggesting a threshold-dependent response. These findings enhance our understanding of plant–nematode interactions and suggest that octanal and 6-methyl-5-hepten-2-one could improve nematode-based slug control strategies. However, environmental factors such as soil composition and microbial activity may influence VOC diffusion and nematode recruitment. Future research should focus on optimizing VOC formulations, assessing field applicability, and integrating these findings into sustainable pest management programs. Full article