Mitochondrial ACSS1 links acetate metabolism to pyrimidine biosynthesis in nutrient-stressed B-cell lymphomas.

Messenger RNA degradation is a fundamental layer of gene regulation; however, its system-level impact on bacterial physiology remains poorly understood. Here, we show that RNase E, RNase II, and RNase R act both independently and synergistically to control Escherichia coli growth and metabolism across diverse carbon sources and bioproduction conditions. Unexpectedly, C-terminal truncation of RNase E, either alone or in combination with RNase II or RNase R, modulates glycogen and acetate metabolism and improves growth performance. Enhanced recombinant protein production was also observed, and the underlying mechanism was investigated. By directly linking the RNA degradation machinery to metabolic regulation and cellular performance, this work highlights RNases as powerful and underexploited targets for engineering improved microbial chassis for biotechnology.

Ultra-processed food intake and its associations with atherogenic dyslipidemia, glycemic control, and gut microbiome features in adults with type 1 diabetes from Southern Italy.

Characterization of dry- and fresh-period mammary plasma flow and metabolism and their association with colostrum production in multiparous Holstein cattle.

Bifidobacterium pseudolongum alleviates chronic intermittent hypoxia-induced cognitive impairment by restoring acetate metabolism and suppressing hippocampal neuroinflammation and neuronal PANoptosis.

Proteomics of the extremotolerant yeast Meyerozyma guilliermondii 4LYP0 isolated from the Yanamate tailings Cerro de Pasco (Peru) upon exposure to Cu2+, Cd2+, and Cr6＋ ions.

In bacterial oncotherapy, tumor-targeting bacteria deliver cytotoxins that induce cancer-cell apoptosis, requiring exogenous cues to induce such cytotoxins. We mined the part of the Escherichia coli genome regulating immunotoxin (anticancer protein) to maximize tumor-specific activity. E. coli was introduced into a mouse tumor model, and RNA-seq analysis was performed. csrB, encoding small regulatory RNA, was highly upregulated in tumors. Genes controlled by csrB participate in acetate metabolism, enriched in the tumor microenvironment. qPCR of in vitro bacterial culture revealed that csrB expression depended on acetate levels. The csrB-promoter regulated acetate-controlled expression of β-galactosidase. For E. coli-mediated oncotherapy, we therefore selected the csrB promoter to regulate a recombinant form of immunotoxin, psp-TGFα-PE38, comprising TGFα, Pseudomonas exotoxin A, with a secretion tag (psp). Under csrB-promoter control, TP was notably expressed when acetate was present. Tumor-cell viability was dramatically reduced following treatment with the TP-containing bacterial-culture supernatant. TP was continuously present in the tumors of CT26-tumor-bearing mice administered TP-expressing E. coli. When exogenous stimuli were absent and TP was expressed by E. coli, tumor growth was substantially retarded, and the survival period increased. Tumor-colonizing bacteria thus offer promise in sensing tumor conditions and altering antitumor protein expression, potentially improving outcomes.

Host analysis-guided selection and targeted engineering (HASTE) of Lipomyces tetrasporus for the conversion of CO2-derived feedstocks.

Acetate-based biological platforms: Bridging carbon dioxide utilization and high-value bioproduct production in oleaginous yeasts.

Alcohol consumption elevates circulating acetate. Prior studies showed that acute alcohol reduces brain glucose uptake and increases brain acetate oxidation. Previously we showed that heavy drinkers have elevated capacity to oxidize brain acetate. Here we repeat the study, adding individuals with alcohol use disorder (AUD). Four groups were enrolled. The analysis data set included Light Drinkers (LD, n = 13, female = 5), at-risk Heavy Drinkers (HD, n = 15, female = 7), AUD patients in long-term recovery (≥6 months; AUDLTR, n = 6, female = 1), and a separate group of AUD treatment-seekers (AUDTx, n = 12, female = 1) underwent medically supervised detoxification, scanned at ~1 week abstinence (n = 9) and 1 month (n = 10). Seven AUDTx participants successfully completed scans at both time points. We infused participants with [2-13C]acetate during magnetic resonance spectroscopy (MRS) of 13C-glutamate (Glu) and 13C-glutamine (Gln) in the brain, to measure the cerebral metabolic rate for acetate (CMRAc) and the neuronal tricarboxylic acid cycle relative to glutamate-glutamine neurotransmitter cycling (VtcaN/Vcycle; Energy Per Cycle: EPC). There was a group effect for CMRAc (p = 0.007) primarily owing to lower CMRAc in AUDTx at 1 week. Furthermore, higher CMRAc was observed among HD compared to LD participants, as previously reported. CMRAc was similar between the AUDLTR and HD groups. In a separate within-subject comparison among AUDTx participants, CMRAc increased after 1 month to levels similar to those of LD. EPC was similar among the groups, representing normal glutamate-glutamine cycling versus energetics. In summary, abstinence reversed the lower acetate oxidation in early AUD, showing that just a few weeks of recovery can normalize this metabolic abnormality.

Ammonia is an essential nutrient for anaerobic digestion (AD) but becomes inhibitory at elevated concentrations, leading to process instability. Although numerous microbial taxa and functional genes have been proposed as indicators of ammonia stress, most lack systematic validation across defined inhibitory thresholds. In this study, batch anaerobic digestion assays were conducted under increasing total ammonia nitrogen concentrations to experimentally characterize ammonia-induced inhibition. Methane yields obtained from batch tests were fitted using a Hill model to define non-inhibitory, inhibitory, and minimum inhibitory ammonia levels. Shotgun metagenomic sequencing was applied to samples representative of each inhibition level, and a statistical framework integrating differential abundance analysis, network topology, redundancy analysis, and metabolic relevance was used to identify robust microbial indicators. Key taxa, including Anaerolinea, Methanomassiliicoccus, and Syntrophobacter, along with functional genes involved in acetate and propionate metabolism (e.g., acs and fhs), showed consistent and threshold-dependent responses to ammonia stress. These microbial indicators provide mechanistic insight into ammonia-induced AD instability and offer a promising basis for early-warning monitoring and microbial management strategies to improve the operational stability of anaerobic digesters treating food waste.

Streptococcus canis represents a major canine pathogen, accounting for 22.4% of streptococcal infections in dogs. However, despite its prevalence in veterinary medicine, the mechanisms underlying S. canis pathogenesis and survival remain poorly understood. Identifying targeted treatments against S. canis could help to reduce dysbiosis-related complications and minimize the selection of resistant neighbouring bacteria. In this study, we employed transposon-directed insertion-site sequencing for the first time to generate saturated mutant libraries of S. canis. By comparing three distinct strains, we defined the shared essential genome of this pathogen. We found that 90.4% of its essential genes are also present in the essential genomes of other related pyogenic streptococcal species, including Streptococcus pyogenes, Streptococcus agalactiae and Streptococcus equi subsp. equi, demonstrating the translational relevance of S. canis research to broader streptococcal biology. Notably, we identified two genes uniquely essential to S. canis at the terminal steps of glycolysis: ldh, which governs lactate metabolism, and pta, which catalyses the conversion of acetyl-CoA to acetyl phosphate in acetate metabolism. We propose that targeting these pathways may offer a novel, species-specific therapeutic strategy for treating S. canis infections.

Targeting ACSS2 disrupts metabolic-epigenetic crosstalk to restore apoptosis and temozolomide chemosensitivity in pancreatic neuroendocrine tumors.

Enhanced acetate tolerance and resource recovery via adaptive evolution of Chlorella vulgaris for sustainable upcycling of organic wastewater.

Understanding the succession of soil microbial carbon metabolism functions is crucial for elucidating carbon cycling mechanisms during ecosystem restoration in sandy lands. Soils were collected from Caragana korshinskii shrubland sites across a restoration chronosequence (0, 10, 30, 50, and 70 years) in the Mu Us Sandy Land. Biolog carbon source utilization analysis and metagenomic sequencing were employed to characterize the successional patterns of microbial carbon metabolism functions-a shift in carbon metabolism strategies from acquisition to conservation, and a transition in functional diversity from generalism to specialization. The results indicated that microbial communities exhibited two associated successional shifts in functional characteristics: carbon source utilization tended to transition from simple to complex substrates, while functional gene expression showed a progressive shift from broad multi-pathway patterns toward pathway-specific specialization. AWCD values increased continuously with restoration duration, and carbon source utilization patterns diverged significantly around 30 years. Early-stage sites (0-30 years) primarily utilized simple carbon sources, whereas late-stage sites (50-70 years) shifted toward more complex and diverse substrates. Principal component analysis revealed that 27 carbon sources contributed 91.3% of the variance to PC1. Microbial community structure succession revealed that Actinobacteria peaked at 10 years (43.63%), Proteobacteria peaked at 30 years (45.66%), and taxa such as Bacilli and Solirubrobacter dominated at 50-70 years. Carbon metabolism pathways exhibited stage-specific succession: glycolysis and the ED pathway were active in early stages, acetate metabolism dominated with the 3HB cycle peaking in intermediate stages, and the CBB cycle increased in later stages while methane metabolism shifted from high to low contribution. These two associated successional shifts occurred along the same restoration chronosequence, with the progressive transition in substrate utilization accompanying the development of specialist functional characteristics. These findings provide insights into the successional dynamics of microbial carbon metabolism during vegetation restoration, offering a microbiological basis for optimizing ecological restoration practices and enhancing soil carbon sequestration in sandy lands.

Heterogeneous selection driven by pH determines the successional pattern of bacterial communities in pit mud used for Baijiu fermentation.

BackgroundTo overcome the limitations in the production of polyhydroxybutyrate (PHB) in cyanobacteria, we genetically modified Synechocystis sp. PCC 6803 focusing on carbon metabolism at the phosphoketolase pathway. In addition, for the baseline of the control strain (Ct), an inhibition of the pyruvate-to-lactate reaction was created by the disruption of the native ddh gene that encodes lactate dehydrogenase.ResultsThe effects on cell growth of phosphoketolase (pk) gene expression derived from Pseudomonas aeruginosa ATCC 15442 (Ct_OXpkPa), Bifidobacterium breve strain 203 (Ct_OXpkBb), and Bifidobacterium adolescentis ATCC 15703 (Ct_OXpkBa) were comparable to that observed in the Ct strain. Notably, the PHB production in the Ct_OXpkBb strain increased under the normal growth condition without any stress, reaching 32.5% of dry cell weight. Combined nitrogen and phosphorus deprivation, the Ct_OXpkBb strain significantly accumulated PHB up to 62.2% of dry cell weight within 7 days of treatment. Compared with the Ct strain, the Ct_OXpkBb strain also exhibited a significant reduction in glycogen, in accordance with decreased glgC transcript levels for glycogen synthesis and increased glgX transcript levels for glycogen degradation. Furthermore, under the NP-deprived condition, the Ct_OXpkBb strain exhibited reduced transcript levels of acetate metabolism genes, in particular ackA and acs, compared with the control condition.ConclusionsSynechocystis PCC 6803 expressing pk from Bifidobacterium breve strain 203 resulted in significant production of PHB, indicating its potential for biotechnological applications.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13068-026-02752-8.

[¹¹C]Acetate-positron emission tomography (PET), widely applied in cardiology and oncology, offers unique potential as a noninvasive imaging method for assessing oxidative metabolism in metabolic disorders. In this study, we investigated its ability to detect early metabolic changes in the diet-induced model of metabolic dysfunction-associated fatty liver disease (MAFLD). Sprague Dawley rats were maintained on either a standard diet or a high-fat diet for 10 weeks before undergoing dynamic [11C]acetate-PET/computed tomography measurement. Four weeks later, radiometabolite analysis was performed in half of the animals, while the remainder underwent nonradioactive blood gas measurements. Uptake of [11C]acetate at 60 min after administration was quantified in the kidneys, myocardium, and liver (SUVmean and SUVmax), followed by analysis of time activity curves (employing AUC), alongside monoexponential clearance rates (kmono) and kinetic modeling using 1- and 2-tissue compartment models (Vt). MAFLD animals exhibited altered [¹¹C]acetate metabolism, with [11C]CO2 excretion patterns validated by non-radiative blood gas analyses. While healthy rats showed a radiometabolite peak at ∼30 min postinjection, MAFLD rats displayed an earlier maximum at 5 min and a secondary peak at 40 min, indicating a shift in longitudinal oxidative metabolism. Despite contradictions between SUVs and kmono, compartmental modeling demonstrated a clear separation of healthy from MAFLD groups, solely in hepatic volume of distribution (Vt). These results establish repurposing of [11C]acetate-PET, particularly when combined with metabolite correction, as a sensitive approach for phenotyping and identifying metabolic alterations in MAFLD and also hold translational promise for understanding and monitoring of other obesity-related liver dysfunctions.

Redefining HexR regulatory landscape in Pseudomonas putida KT2440 through integrative systems biology.

Abstract Photofermentative biohydrogen production (PFHP) is a promising route for sustainable biohydrogen production, but its efficiency is constrained by inefficient intra/extracellular electron transfer (IET/EET). Biochar (BC) provides unique characteristics to enhance IET/EET in biochemical systems; however, non-conductive polymer groups hinder its charge transfer efficiency. The present study proposes the engineering of the microbial-electrochemical interface through dual metal (Co and Fe) functionalization of BC to improve charge transfer within the fermentative medium, thus leading to an increase in hydrogen production. SEM, BET, XPS, and Raman spectroscopy demonstrated that Co-Fe/BC functionalization results in 22.83% higher porosity and surface area compared to pristine biochar (PBC) and single metal functionalization, suggesting increased electrons from surface defects like oxygen vacancies (OVs). The optimal loading concentration (20 mg/L) of Co-Fe/BC enhanced the biohydrogen production rate and yield by 101.61% and 103.11%, respectively, exceeding the control group (CG). Electrochemical studies showed that the lowest interfacial charge transfer resistance (1.74 Ω, 1.22 mA redox current) in Co-Fe/BC increases charge transfer capabilities by 106.77% compared to PBC (4.66 Ω, 0.59 mA redox current) thus serving as an electron shuttle to increase redox sites through flavin and c-cytochrome. IET/EET enhancement in a bioreactor loaded with Co-Fe/BC regulates butyric acid to acetic acid metabolism, as revealed by microbial community analysis, where Clostridium was 86.72% more prevalent than CG (79.77%). This work demonstrates that Co-Fe functionalized BC not only bridges electron transfer bottlenecks but also provides a conductive interface for sustained microbial-electrochemical interactions, offering a scalable strategy for optimizing renewable biohydrogen production. Graphical Abstract