Search Results (1,823)

Microalgal biotechnology is gaining attention due to its potential to produce pigments, lipids, biofuels, and value-added products. However, challenges persist in terms of the economic viability of microalgal lipid production in photobioreactors due to slow growth rates, expensive media, complex downstream processing, limited product yields, and contamination risks. Recent studies suggest that co-cultivating microalgae with bacteria can enhance the profitability of microalgal bioprocesses. Immobilizing bacteria offers advantages such as protection against shear forces, the prevention of overgrowth, and continuous product secretion. Previous work has shown that biopolymeric immobilization of Paenibacillus polymyxa enhances 2,3-butanediol production. In this study, a novel co-fermentation process was developed by exploiting the chemical crosstalk between a freshwater microalga Scenedesmus obliquus, also known as Tetradesmus obliquus, and an immobilized plant-growth-promoting bacterium, Paenibacillus polymyxa. This co-cultivation resulted in increased metabolite production, with a 1.5-fold increase in the bacterial 2,3-butanediol concentration and a 3-fold increase in the microalgal growth rates compared to these values in free-cell co-cultivation. Moreover, the co-culture with the immobilized bacterium exhibited a 5-fold increase in the photosynthetic pigments and a 3-fold increase in the microalgal lipid concentration compared to these values in free-cell co-cultivation. A fixed bed photobioreactor was further constructed, and the co-cultivation bioprocess was implemented to improve the bacterial 2,3-butanediol and microalgal lipid production. In conclusion, this study provides conclusive evidence for the potential of co-cultivation and biopolymeric immobilization techniques to enhance 2,3-butanediol and lipid production. Full article

The aim of this study was to compare the human intestinal microbiota in different age groups, elucidating the precise stages of life in which the gut microbiota evolves its specific characteristics in terms of composition and diversity, as well as associating different bacterial groups for prediction of their intertwined metabolic role, considering their importance in human health. The quantitative composition, Bacteroidetes/Firmicutes (B/F) ratio, counts and diversity indices of faecal samples obtained from infant, child, adult and elderly individuals were assessed via quantitative real-time polymerase chain reaction (qPCR). The intestinal microbiota of infants expressed the highest B/F ratio and diversity. The total bacteria counts, Bacteroides-Prevotella and Blautia coccoides-Eubacterium rectale groups were the most abundant in adults and infants, while child and elderly individuals presented the highest counts of Firmicutes and Lactobacillus sp. In infants, the counts of Enterococcus sp., Streptococcus sp., Enterobacteriaceae, Veillonella sp. and Clostridium perfringens groups were higher, when compared to the other age groups. The tightest positive correlations between bacteria within age groups were found for the B. coccoides-E. rectale, C. leptum (incl. Faecalibacterium prausnitzii), Bacteroidetes-Prevotella and Atopobium groups. Through the stages of life, the quantitative composition and diversity of intestinal microbiota evolves with two changing maximal peaks of predominant groups, with bacterial diversity decreasing from infant to child stage, showing unitary stabilization in adults and presenting a wide individual range in the elderly. The high counts of Bacteroidetes and Clostridium from the phylum Firmicutes, present throughout all life stages, mainly influence the composition and metabolic activity of other bacteria. Recognizing age-specific differences may provide a basis for comparing different geographic populations and predicting the intertwined metabolites of various bacteria, which have certain implications for health. Full article

Background/Objectives: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by the progressive degeneration of motor neurons. The gut microbiota, a community of microorganisms in the digestive tract, has recently been implicated in ALS pathogenesis through its influence on neuroinflammation and metabolic pathways. This review explores the potential role of digestive microbiota and its metabolites in ALS progression and investigates therapeutic approaches targeting gut microbiota. Methods: A comprehensive review of the current literature was conducted to assess the relationship between gut microbiota composition, microbial metabolites, and ALS progression in patients. We searched for published reports on microbiota composition, microbial metabolites, and ALS, emphasizing the complex interplay between dysbiosis, neuroinflammation, and systemic metabolism. Special emphasis was placed on studies exploring short-chain fatty acids (SCFAs), bacterial amyloids (curli-like factors), and neurotoxins such as β-methylamino-L-alanine (BMAA). The role of the liver–gut axis was evaluated as well. The potential changes in microbiota would sustain the rationale for therapeutic strategies such as probiotics, prebiotics, fecal microbiota transplantation (FMT), and dietary interventions. Results: ALS patients exhibit gut dysbiosis, characterized by reduced SCFA-producing bacteria and an increase in potentially pathogenic genera. Of note, different studies do not agree on common patterns of microbiota being linked to ALS, supporting the need for further, more extensive studies. Dysbiosis sometimes correlates with systemic inflammation and disrupted liver function, amplifying neuroinflammatory responses. Key microbial metabolites, including SCFAs, bacterial amyloids, and BMAA, may exacerbate motor neuron degeneration by promoting protein misfolding, oxidative stress, and neuroinflammation. Emerging therapeutic strategies, including probiotics and FMT, show potential in restoring microbial balance, although clinical data in ALS patients remain limited. Conclusions: The gut microbiota could modulate neuroinflammation and systemic metabolism in ALS. Microbiota-targeted therapies, such as probiotics and dietary interventions, represent promising avenues for mitigating disease progression. Further research is required to validate these interventions through large-scale, longitudinal studies and to develop personalized microbiota-based treatments tailored to individual ALS phenotypes. Full article

The study of seepage laws during microbial enhanced oil recovery helps to elucidate the mechanisms behind microbial flooding, and the use of large-scale physical simulation experimental devices can more objectively and accurately investigate the seepage laws of microbes in porous media, and evaluate the oil displacement efficiency of microbial systems. In this study, physical simulation experiments of microbial flooding were conducted via a slab outcrop core, and the biochemical parameters such as the concentration of Bacillus subtilis, nutrient concentration, surface tension, and displacement pressure data were tracked and evaluated. The analysis revealed that the characteristics of the pressure field change during microbial flooding and elucidates the migration rules of microbes and nutrients, as well as the change rule of surface tension. The results show that after the microbial system is injected, cells and nutrients are preferentially distributed near the injection well and along the main flow paths, with the bacterial adsorption and retention capacity being greater than those of the nutrient agents. Owing to the action of microorganisms and their metabolites, the overall pressure within the model increased, From the injection well to the production well, the pressure in the model decreases stepwise, and the high-pressure gradient zone is mainly concentrated near the injection well. The fermentation mixture of Bacillus subtilis increased the injection pressure by 0.73 MPa, reduced the surface tension by up to 49.8%, and increased the oil recovery rate by 6.5%. Full article

Bark beetle-associated bacteria from the sub-boreal and boreal forests of northern Canada represent a largely unexplored source of bioactive natural products. This study aims to investigate the chemical potential of bacteria isolated from Dendroctonus ponderosae, Dendroctonus rufipennis, Dendroctonus pseudotsugae, and Ips perturbatus by focusing on nitrogen-containing secondary metabolites. Genomic analyses of the bacterial isolates identified diverse biosynthetic gene clusters (BGCs), including nonribosomal peptides (NRPs), NRPS-PKS hybrids, and ribosomally synthesized and post-translationally modified peptides (RiPPs), many of which exhibit low sequence homology, suggesting potential for novel bioactive compounds. Nitrogen-15 NMR spectroscopy was employed to detect nitrogen-containing functional groups in crude extracts, revealing distinct signals for amides, amines, and nitrogen heterocycles. The combination of BGC predictions and NMR data highlighted the genetic and chemical diversity of these bacteria and underscored the potential for discovering novel nitrogen-rich metabolites. These findings provide a foundation for further exploration of bioactive natural products with pharmaceutical and agrochemical applications and potential to contribute to the understanding of the chemical ecology of bark beetle–microbe interactions in northern ecosystems. Full article

In countries with a long petroleum extraction and processing history, such as Romania, extensive soil areas are often polluted with petroleum and its derivatives, posing significant environmental and human health risks. This study explores the diesel biodegradation potential of two native bacterial consortia isolated from hydrocarbon-polluted soils, focusing on their phenotypic and molecular characteristics, growth kinetics, alkane hydroxylase activity, hydrolase production, and biosurfactant synthesis capabilities. The bacterial consortia, CoP1 and CoP2, were successfully obtained using the standard successive enrichment culture method from two soil samples collected from a region affected by petroleum pollution. The CoP1 and CoP2 consortia demonstrated efficient diesel-degrading capabilities, achieving 50.81−84.32% degradation when cultured in a minimal medium containing 1–10% (v/v) diesel as the sole carbon and energy source. This biodegradation potential was corroborated by their significant alkane hydroxylase activity and the detection of multiple catabolic genes in their genomes. The CoP1 consortium contains at least four catabolic genes (alkB, alkM, todM, ndoM) as well as rhamnosyltransferase 1 genes (rhlAB), while the CoP2 consortium contains only two catabolic genes (ndoM, C23DO). The RND transporter gene (HAE1) was present in both consortia. Secondary metabolites, such as glycolipid-type biosurfactants, as well as extracellular hydrolases (protease, amylase, cellulase, and lipase), were produced by both consortia. The CoP1 and CoP2 consortia demonstrate exceptional efficiency in diesel degradation and biosurfactant production, making them well suited for the bioremediation of soils contaminated with petroleum and its derivatives. Full article

The use of metal nanoparticles is gaining popularity owing to their low cost and high efficacy. We focused on green synthesis of silver nanoparticles (AgNPs) using Tinospora cordifolia (Tc) leaf extracts. The structural characteristics of Tc nanoparticles (TcAgNPs) were determined using several advanced techniques. Pharmacological activities, including antioxidant, anti-inflammatory, and antibacterial properties, were evaluated through in vitro studies. In the results, the change in sample color from yellow to brown after adding silver nitrate revealed the synthesis of TcAgNPs, and the UV–visible spectrum confirmed their formation. X-ray diffraction studies showed the presence of reducing agents and the crystalline nature of the nanoparticles. Fourier-transform infrared spectra revealed the existence of essential secondary metabolites, which act as reducing/capping agents and stabilize the nanoparticles. The size of the TcAgNPs was small (range 36–168 nm) based on the measurement method. Their negative zeta potential (−32.3 mV) ensured their stability in water suspensions. The TcAgNPs were predominantly spherical, as evidenced from scanning electron microscopy and transmission electron microscopy. Atomic absorption spectroscopy data further revealed the conversion of silver nitrate into silver nanoparticles, and thermogravimetric analysis data showed their thermal stability. The TcAgNPs showed significant DPPH/ABTS radical scavenging ability in a concentration-dependent manner (25–100 µg/mL). Membrane lysis assays showed an effective anti-inflammatory activity of the TcAgNPs. Furthermore, the TcAgNPs showed potent antibacterial effects against multidrug-resistant bacteria (Pseudomonas aeruginosa, Klebsiella pneumonia, Escherichia coli, and Staphylococcus aureus). The TcAgNPs treatment also exhibited antibiofilm activity against bacterial strains, in a concentration-dependent manner. Our findings demonstrate the structural characteristics of green-synthesized TcAgNPs using advanced techniques. TcAgNPs can be developed as potential antioxidant, anti-inflammatory, and antibacterial drugs. Full article

Background: Exocrine pancreatic insufficiency in cystic fibrosis (CF) increases fecal choline losses, but the postnatal course of plasma choline and its metabolites in these patients is unknown. While choline homeostasis is crucial for cellular, bile, and lipoprotein metabolism, via phosphatidylcholine (PC) and via betaine as a methyl donor, choline deficiency is associated with impaired lung and liver function, including hepatic steatosis. Objective: The goal of our study was to evaluate the plasma levels of choline, betaine, trimethylamine oxide (TMAO), PC, and PC subclasses in CF patients from infancy to adulthood and compare those with exocrine pancreatic insufficiency (EPI) to those with pancreatic sufficiency (EPS). Methods: Retrospective analysis of target parameters in plasma samples (July 2015–November 2023) of CF patients (0.64–24.6 years) with tandem mass spectrometry. Results: A total of 477 samples from 162 CF patients were analyzed. In CF patients with EPI (N = 148), plasma choline and betaine concentrations were lower and decreased with age compared to EPS patients showing normal values. TMAO concentrations, indicating intestinal choline degradation by bacterial colonization, were frequently elevated in EPI from infancy onwards, and inversely related to plasma choline and betaine levels. PC-containing linoleic acid levels were lower in EPI, but arachidonic and docosahexaenoic acid content was similar in both patient groups. Conclusion: CF patients with EPI are at risk of choline and betaine deficiency compared to exocrine pancreas-sufficient CF patients. Elevated TMAO concentrations in EPI patients indicate increased bacterial colonization leading to choline degradation before absorption. These findings indicate that laboratory testing of choline, betaine, and TMAO as well as clinical trials on choline supplementation are warranted in CF patients. Full article

This study investigates the interplay between volatile and non-volatile flavor metabolites and endophytic microbial communities during three developmental stages of Passiflora ligularis fruit juice. Using bioinformatics and metabolomics, we characterize microbial diversity and metabolic variations to understand flavor development. A total of 1490 bacterial and 1158 fungal operational taxonomic units (OTUs) were identified. Young fruits had higher microbial diversity, dominated by Proteobacteria and Firmicutes (bacteria) and Ascomycota and Basidiomycota (fungi). As the fruit matured, Proteobacteria increased while Firmicutes decreased, indicating that microbial succession is tied to development. Metabolomic profiling identified 87 volatile and 1002 non-volatile metabolites, with distinct chemical classes varying across stages. Saturated hydrocarbons and fatty alcohols were the main volatile metabolites, while organic acids and lipids among non-volatile metabolites showed stage-dependent changes, influencing flavor complexity. Correlation analysis showed microbial-flavor interactions: Proteobacteria negatively correlated with metabolites, while Firmicutes positively correlated with metabolites. Ascomycota positively correlated with volatile metabolites, whereas Basidiomycota showed an inverse relationship, highlighting their differential contributions to flavor biosynthesis. This study enhances understanding of microbial and metabolic factors shaping P. ligularis fruit flavor, highlighting the importance of microbial influence on fruit metabolomics. The findings suggest the potential for microbiome engineering to improve flavor quality, aiding postharvest management and industrial processing in the food and beverage industry. Full article

The purpose of this scoping review was to provide a comprehensive understanding of the current knowledge concerning the gut microbiome and SCFAs as emerging treatments for salt-sensitive hypertension. Relevant animal and human studies were identified via PubMed through August 2024. Twenty-four human (n = 9) and animal (n = 15) trials were included. Most human studies were observational (n = 6), aiming to compare gut microbiota differences between hypertensive and normotensive individuals. Three human studies evaluated microbiome-based interventions either via a sodium-restricted diet (n = 2) or prebiotic supplementation (n = 1). Fifteen animal trials involving either mice or rats were identified, all of which were interventional. These included dietary changes (n = 9), probiotic treatments (n = 1), postbiotic primarily bacterial metabolites (n = 4), and live biotherapeutic products (n = 4). All interventions were effective in decreasing blood pressure. Microbiome-based therapies as biologic modifiers for salt-sensitive hypertension are emerging. Substantial knowledge gaps remain, warranting further research to fully explore this promising therapeutic avenue. Full article

Wound healing is a complicated biological process that is important for restoring tissue integrity and function after injury. Infection, usually due to bacterial colonization, significantly complicates this process by hindering the course of healing and enhancing the chances of systemic complications. Recent advances in wearable biosensors have transformed wound care by making real-time monitoring of biomarkers such as pH, temperature, moisture, and infection-related metabolites like trimethylamine and uric acid. This review focuses on recent advances in biosensor technologies designed for wound management. Novel sensor architectures, such as flexible and stretchable electronics, colorimetric patches, and electrochemical platforms, enable the non-invasive detection of changes associated with wounds with high specificity and sensitivity. These are increasingly combined with AI and analytics based on smartphones that can enable timely and personalized interventions. Examples are the PETAL patch sensor that applies multiple sensing mechanisms for wide-ranging views on wound status and closed-loop systems that connect biosensors to therapeutic devices to automate infection control. Additionally, self-powered biosensors that tap into body heat or energy from the biofluids themselves avoid any external batteries and are thus more effective in field use or with limited resources. Internet of Things connectivity allows further support for remote sharing and monitoring of data, thus supporting telemedicine applications. Although wearable biosensors have developed relatively rapidly and their prospects continue to expand, regular clinical application is stalled by significant challenges such as regulatory, cost, patient compliance, and technical problems related to sensor accuracy, biofouling, and power, among others, that need to be addressed by innovative solutions. The goal of this review is to synthesize current trends, challenges, and future directions in wound healing and infection monitoring, with emphasis on the potential for wearable biosensors to improve patient outcomes and reduce healthcare burdens. These innovations are leading the way toward next-generation wound care by bridging advanced materials science, biotechnology, and digital health. Full article

Lesion mimic mutants provide unique tools to investigate plant–pathogen interactions, often exhibiting hypersensitive responses in the absence of biotic or abiotic stresses. The overexpression of the S-domain receptor-like kinase gene, SPL11 cell-death suppressor 2 (SDS2), in rice leads to constitutive programmed cell death and enhanced resistance to fungal and bacterial pathogens. However, the mechanisms underlying this broad-spectrum resistance remain unclear. This study integrates transcriptomic and metabolomic analyses of the SDS2-ACT mutant to uncover gene expression and metabolic shifts associated with disease resistance. To identify SDS2-specific physiological changes related to pathogen resistance, leaf tissues from the SDS2-ACT mutant and the Kitkaake WT line were subjected to both transcriptomic and non-targeted metabolic profiling. Transcriptomic analyses identified 1497 differentially expressed genes (DEGs), including up-regulated genes involved in terpenoid and flavonoid biosynthesis, phytohormone signaling, and defense-related pathways (including pathogenesis-related [PR] genes). Metabolomic profiling revealed significant alterations in the accumulation of several compound classes, including putative: terpenoids, phenylpropanoids, phytohormones, fatty acids, and sugars. These changes are likely correlated with the observed cell death and resistance phenotypes in the SDS2-ACT mutant. This study provides an overall landscape of the transcriptomic and metabolomic alterations in a lesion mimic mutant, identifying candidate defense-related genes and metabolites for functional analysis in rice. Full article

Gut microbial metabolism of dietary flavonoids leads to a diverse array of bioactive products that are closely associated with human health. Combining enzyme promiscuity prediction, metabolomics, and in vitro model systems, we identified a chalcone-synthase-like bacterial polyketide synthase that can initiate the metabolism of naringenin by catalyzing the C-ring cleavage. This was validated using a mutant strain of the model organism Bacillus subtilis (ATCC 23857). Our prediction–validation methodology could be used to systematically characterize the products of gut bacterial flavonoid metabolism and identify the responsible enzymes and species. In vitro experiments with Caco-2 cells revealed that naringenin and its bacterial metabolites differentially engage the aryl hydrocarbon receptor (AhR) and orphan nuclear receptor 4A (NR4A). These results suggest that metabolism by gut bacterial species could directly impact the profile of bioactive flavonoids and influence inflammatory responses in the intestine. These results are significant for understanding gut-microbiota-dependent physiological effects of dietary flavonoids. Full article

Tonic immobility (TI) serves as an indicator of innate stress response recovery in poultry. Broilers with different TI phenotypes exhibit varying levels of aggressive behavior, which can significantly impact their welfare. However, the influences of TI phenotypes on broiler aggression remain largely unexplored. In this study, broiler chickens were stratified into two distinct phenotypic groups based on the TI duration: short TI (STI) and long TI (LTI). The impacts of TI phenotypes on broiler aggression were investigated by analyzing cecal intestinal morphology, cecal bacteria, plasma metabolites, and corticosterone levels. Compared to LTI broilers, STI broilers showed significantly reduced plasma corticosterone (CORT) levels (p < 0.05) and a decreased frequency of aggressive behaviors, including dominant and subdominant types (p < 0.01). Histological analysis revealed that STI broilers have an increased duodenal villus height and villus-height-to-crypt-depth ratio (p < 0.01), a decreased jejunal crypt depth with an increased villus-height-to-crypt-depth ratio (p < 0.01), and a reduced ileal crypt depth and villus height (p < 0.01) compared to LTI broilers. 16S rDNA sequencing and Linear discriminant analysis effect size (LefSe) identified differential cecal bacterial abundance, notably in the genus cc115 belonging to Firmicutes. Specific microbiota in LTI broilers exhibited significant positive correlations with aggressive behavior and plasma corticosterone, while those in STI broilers showed significant negative correlations. Untargeted plasma metabolomics revealed 21 downregulated and 17 upregulated metabolites between TI phenotypes. Correlation analysis showed that the genus cc115 and 10 plasma metabolites were positively correlated with aggressive behavior, whereas 8 metabolites were negatively correlated. LTI broilers have higher plasma corticosterone content and more intense aggressive behavior than STI broilers. The distinct behavioral and physiological profiles observed in broilers with different TI phenotypes are strongly correlated with their specific gut microbiota and differential plasma metabolite profiles. The identified gut microbial signatures serve as key biomarkers for regulating aggressive behavior in broilers, while the differential plasma metabolites represent potential early indicators for detecting stress and behavioral issues in poultry farming. Full article

Global climate change has accelerated the reduction of permafrost regions across different altitude gradients, shortening the duration of the freezing period to varying extents. However, the response of the soil microorganisms of frozen soils along altitude gradients remains unclear. In this study, we employed 16S rRNA sequencing and LC-MS metabolomics to investigate the response of soil microbial communities and soil metabolites to vertical stratification in the permafrost soils of the Qinghai Lake region. The results indicated that Proteobacteria, Firmicutes, and Actinobacteria were key soil bacterial phyla in the permafrost soils of Qinghai Lake during the freezing period, with Proteobacteria and Firmicutes showing significant sensitivity to vertical stratification (p < 0.05). The majority of the physicochemical factors exhibited a trend of initially increasing and then decreasing with increasing altitude, whereas pH showed the opposite trend. pH and moisture content were identified as the most important environmental factors influencing soil bacterial community structure. Deterministic processes dominated the assembly of bacterial communities of frozen soils in the Qinghai Lake basin. Co-occurrence network analysis showed that increasing altitude gradients led to a higher average degree of the bacterial network, while reducing network complexity and inter-species connectivity. Soil metabolomics analysis revealed that vertical stratification altered the metabolic profiles of 27 metabolites, with the significantly changed metabolites primarily associated with carbohydrate and amino acid metabolism. In conclusion, the characteristics of the Qinghai Lake permafrost were regulated by regional vertical stratification, which further influenced microbial community structure and soil metabolic characteristics, thereby altering carbon and nitrogen stocks. Specifically, higher altitudes were more favorable for the retention of the carbon and nitrogen stocks of frozen soils in the Qinghai Lake basin. Full article