Search Results (233)

Oilfield-produced water contains petroleum hydrocarbons, suspended solids, salts and other refractory constituents that challenge conventional biological treatment. Suspended activated sludge systems can suffer from microbial washout, poor retention of slow-growing functional microorganisms and unstable settling, whereas conventional ceramic biofilm packings often provide limited surface area and slow biofilm start-up. Here, a modified polyurethane biosponge was evaluated as a three-dimensional carrier for immobilized microbial growth during the treatment of real oilfield produced water. Three parallel systems were compared under identical start-up and operating conditions: suspended activated sludge without a carrier, Raschig ring-packed biofilm reactors, and the biosponge-based composite system. The biosponge system developed a visible and stable biofilm within 7 days, whereas the Raschig ring system showed only sparse and uneven biofilm coverage. During an 8-day treatment test with real produced water, the biosponge system decreased the COD concentration from 800 to 13 mg L⁻¹ in the aerobic zone and from 1500 to 16 mg L⁻¹ in the anoxic zone, corresponding to removal efficiencies of 98.4% and 98.9%, respectively. In contrast, the activated sludge and Raschig ring systems showed much lower COD removal under the same test period. 16S rRNA gene sequencing indicated that the biosponge selectively enriched petroleum hydrocarbon-associated genera, including Sphingopyxis, Achromobacter and Gordonia, in the aerobic zone, together with fermentative and anaerobic genera such as Dysgonomonas and Clostridium in the anoxic zone. PICRUSt2-based functional prediction further suggested the coexistence of aerobic hydrocarbon degradation, chemoheterotrophy, fermentation and nitrate respiration potentials. These results indicate that the modified polyurethane biosponge provides a favorable carrier for rapid biofilm establishment and short-term removal of organic pollutants from oilfield produced water. Further long-term operation, adsorption controls and direct functional gene validation are recommended to confirm the engineering robustness and degradation mechanisms of the system. The system also avoided sludge bulking and maintained short-term stability, providing a promising low-cost strategy for treating high-salinity refractory oilfield produced water. Full article

Bacterial terminal oxidases are essential for growth and may provide protection against environmental stressors. Bacteria often have to cope with ammonia, which, although an essential nutrient, is toxic at high concentrations. Here, we studied the influence of ammonia on the cell growth of three different Escherichia coli respiratory mutants, each possessing a single terminal oxidase: cytochrome bd-I, cytochrome bd-II, or cytochrome bo₃. We also investigated the effect of ammonia on O₂ consumption in cytochrome bd-II-only cells and membranes, as well as in the isolated bd-II enzyme. Using microcalorimetry, spectrophotometry and high-resolution respirometry, the following new results were obtained: (i) At pH 8.3, the addition of ammonia to both bd-I-only and bd-II-only cell cultures has virtually no effect on growth. In contrast, the growth of bo₃-only cells is significantly impaired. (ii) The addition of ammonia to bd-II-only intact cells at pH 8.3 not only fails to inhibit their respiration but also accelerates O₂ consumption. The same is observed with bd-II-only isolated membranes and detergent-solubilized bd-II enzyme. The maximum increase in cytochrome bd-II O₂ consumption rate is approximately 150%. Physiological aspects of the findings are discussed, and molecular mechanisms for ammonia-induced acceleration of O₂ consumption by cytochrome bd-II are suggested. Full article

Background/Objectives: Systemic inflammation and circulating proinflammatory cytokines can impair blood–brain barrier (BBB) integrity. Many in vitro BBB models lack the complexity to fully recapitulate systemic inflammation and its long-term effects on the BBB. This study aimed to develop a hollow-fiber flow-based dynamic in vitro (DIV) BBB model for investigating prolonged proinflammatory responses under physiological flow conditions. Methods: Culture conditions for hCMEC/D3 in a DIV model (Flocel) were optimized by varying serum concentrations over seven weeks. Barrier integrity (transendothelial electrical resistance (TEER), permeability studies), proliferation, metabolism (NMR spectroscopy) and molecular changes (high-throughput qPCR) were assessed. Optimized triple-cultures with hCMEC/D3, human primary astrocytes and pericytes were established. After four weeks of barrier establishment, the triple-cultures were exposed to TNF-α, IL-1β and IFN-γ (0.1 ng/mL or 10 ng/mL each) for two weeks. The inflammatory response was assessed with a multiplex cytokine array. Results: Reduced serum concentration (0.25% FBS) decreased proliferation, promoted aerobic respiration, and altered tight junction and transporter gene expression, accompanied by moderately improved barrier integrity compared with 1% or 5% FBS. In optimized triple-cultures, cytokine exposure induced concentration-dependent secretion of IL-6, IL-8, and MCP-1 and changes in mRNA levels, with minor effects on barrier integrity. Sustained cytokine release over two weeks demonstrated stable induction of inflammatory responses at the BBB. Conclusions: An organotypic DIV model of the human BBB, incorporating hCMEC/D3, human primary astrocytes and pericytes was successfully established. By enabling long-term exposure to physiologically relevant cytokine concentrations under flow conditions, this model may provide a platform to investigate functional and molecular BBB responses in inflammation-driven disease progression. Full article

Approximately 30% of the food produced worldwide is wasted, and a substantial share of municipal food waste still contains non-biodegradable packaging material after sorting. This study investigated an aerobic biodrying process for reducing the moisture content of mixed food-waste fractions, containing varying proportions of green biomass, vegetables, kitchen waste, and packaging-derived plastics, in order to increase their calorific value and obtain a refuse-derived fuel (RDF). Four substrate variants (K1–K4, including a control without added plastics) were biodried in laboratory-scale bioreactors. Process temperatures exceeded 70 °C in all variants, and the addition of plastics increased both the cumulative and the average temperature relative to the control. The plastic fraction recovered after biodrying showed the largest increase in calorific value, reaching over 15 MJ∙kg⁻¹, while the AT4 respiration activity of the separated compost fraction decreased to around 10 mg O₂ g⁻¹ DM in all variants, indicating good storage stability. The results suggest that pre-treated plastics did not adversely affect the biodrying process and, owing to their structuring properties, may support biological decomposition of the remaining biomass; these preliminary, single-run findings should be confirmed in replicated trials. Full article

Common bean (Phaseolus vulgaris L.) is a strategic crop whose sustainable production depends on symbiosis with nitrogen-fixing bacteria. However, the composition and functional potential of the nodule microbiome in varieties adapted to semi-arid regions, such as northern Mexico, remain poorly documented. Therefore, this study evaluated the influence of host genotype on nodule-associated bacterial communities in three improved varieties (Pinto Bravo, NOD1, and Jamapa) under conventional management, using high-throughput sequencing of the V3–V4 regions of the 16S rRNA gene. Alpha and beta diversity analyses showed no significant differences among varieties, indicating a similar nodular microbiome regardless of genotype. At the phylum level, Proteobacteria and Bacteroidota predominated, suggesting a conserved microbial core. At the genus level, Rhizobium was the most abundant taxon, while non-rhizobial genera such as Acinetobacter and the JC017 lineage were also detected. Functional prediction using PICRUSt2 revealed conserved metabolic profiles, with dominant pathways associated with amino acid biosynthesis, carbon metabolism, aerobic respiration, and fatty acid biosynthesis, indicating metabolic redundancy linked to tolerance to osmotic, thermal, and oxidative stress. The results suggest that under semi-arid conditions, the symbiotic interaction is governed by mechanisms at the host species level (P. vulgaris), which ensure the recruitment of a functional core microbiome, whereas intraspecific variation among improved varieties may influence the recruitment of specific accessory taxa. Full article

Cancer cells, like yeast, use fermentation despite the presence of oxygen, a phenomenon called aerobic glycolysis. The advantage is that it maintains many C-C bonds of glucose, allowing highly proliferating cells to produce the biomolecules that are necessary for cytokinesis. However, aerobic glycolysis is less energy-efficient than respiration, and it must operate at high frequency and produces large amounts of lactate, which modifies and stimulates DNA repair enzymes via lysine lactylation. This makes cancer cells resistant to radiotherapy, which requires a combination with chemotherapy using drugs that inhibit DNA repair. However, this converts healthy cells to cancer cells, indicating that research is still required regarding the relationship between glycolysis and cancer. Using yeast as a model, we discovered that the glycolytic enzymes TPI and GAPDH (Tpi1p and Tdh1-3p in yeast) interact with the DNA damage-dependent Checkpoint Rad9p (53BP1/BRCA1/MDC1 in humans). We propose that Tpi1p and Tdh1-3p override Rad9p, allowing cells with damaged DNA to proliferate. We isolated tpi and gapdh mutant strains that are deficient in DNA repair. While the tpi mutant strain has lower enzymatic activity, the gapdh mutant strains have normal enzymatic activity, confirming previous reports that GAPDH moonlights in the DNA damage response. Full article

The family of Nek kinases has 11 human members that are conserved in their kinase domains but diverse in their regulatory domains. Functionally, they can be associated with diverse aspects of cell cycle regulation, from mitosis and primary cilia function to centrosome disjunction in the G2 phase and checkpoints of the DNA damage response. However, novel functional contexts have emerged in recent years, including regulatory roles of Neks 1, 4, 5, and 10 in mitochondrial metabolic and morphological homeostasis. We recently generated, by CRISPR-Cas9 technology, a DU-145 prostate cancer cell line, with an NEK6 gene knockout. Here, we focus on a detailed characterization of changes in this cell line, in mitochondrial respiration function and morphology. DU-145 NEK6 knockout cells exhibited reduced mitochondrial respiration and a fragmented phenotype in electron microscopy, with reduced mitochondrial cristae numbers. Alterations in mitochondrial architecture and respiration were correlated with increased expression of anaerobic glycolytic proteins (HK2, PFKP, and LDHA) and decreased expression of PDH, an enzyme of aerobic glycolysis. Molecular analysis by Western blot revealed decreased levels of mitochondrial mass and biogenesis protein markers (TOM20, TFAM), without alterations in other markers such as VDAC1/3 or mtDNA copy number in the NEK6 knockout cells. Furthermore, the regulators of mitochondrial fusion/fission are altered in the knockout cells (decrease in the Long-OPA1:Short-OPA1 ratio and DRP1 total level), which is associated with an increase in endoplasmic reticulum–mitochondria contact at ≤20 nm observed in transmission electron microscopy (TEM) image analysis. Using analysis of TEM micrographs, we found an increase in the autophagic structures (autophagosome, amphisome, and autolysosome), with mitochondria as cargo in some structures, which was correlated with a decrease in LC3A/B and an increase in the BECLIN1 total level, and with an increase in acidic vesicles approximation, suggesting that reduction in TOM20 and TFAM without alterations in VDAC1/3 and mtDNA copy number might be related to mitochondrial degradation through autophagy. Together, our data suggest a new role for NEK6 in regulating mitochondrial homeostasis, where its loss alters mitochondrial morphology and respiration, and could be associated with an increase in the degradation of the dysfunctional mitochondria through autophagy. Full article

The invasive fungal pathogen Pseudogymnoascus destructans is responsible for the collapse of several North American bat species through an infectious fungal skin disease known as White-Nose Syndrome (WNS). Recent transcriptomic studies have suggested that trace copper ion acquisition is essential for P. destructans propagation on its animal hosts. However, little is known about the mechanistic details of P. destructans adaptation occurring at the protein level. In this study, we report the global proteomic adaptation of P. destructans under chronic Cu-stress growth conditions employing chemically defined media. We identify 4340 P. destructans proteins, or approximately 47.8% of the predicted proteome, spanning a dynamic intensity range of six orders of magnitude. Chronic Cu-withholding stress leads to substantial alterations in the proteome, with 1398 differentially abundant proteins (DAPs) exhibiting statistically significant (p < 0.05) changes in protein levels compared to control growth conditions. We find that Cu-withholding stress induces increased levels of proteins associated with high-affinity Cu-acquisition, changes in intracellular superoxide dismutase (SOD) levels, and alterations in mitochondrial proteins related to aerobic respiration. In contrast, chronic Cu-overload stress leads to 390 DAPs (p < 0.05), which are more widely distributed across the proteome, with several DAPs associated with genomic stability and basic metabolism. Additionally, in this report, we present assessment of antisera products against intracellular and cell-surface protein targets of P. destructans that are effective for indicating Cu-withholding stress by western blotting. Together this report, provides insight into P. destructans adaptability to copper stress and identifies fungal proteins that may alleviate copper stress in the WNS infection niche. Full article

Neuroblastoma remains a formidable pediatric malignancy characterized by profound metabolic plasticity and limited therapeutic responsiveness in high-risk disease. Emerging evidence positions the interplay between Reactive Oxygen Species (ROS) and the metabolic sentinel AMP-activated protein kinase (AMPK) as a critical regulator of tumor metabolic stress and apoptotic susceptibility, with additional implications in the systemic pathology of Cancer Cachexia. Building on our previous work demonstrating that 1,1-Diethoxyethane (1,1-DEE; Biosacetalin), a volatile aroma compound inhibits mitochondrial complex I, induces ROS production, and activates AMPK-PGC1α-mediated mitochondrial biogenesis accompanying enhancement of aerobic respiration, leading to anti-Warburg effect. We identify 1,1-DEE as a previously unrecognized metabolic modulator with potent antitumor activity. 1,1-DEE triggers ROS-induced AMPK activation, leading to apoptotic elimination of neuroblastoma cells (SH-SY5Y), robust suppression of tumor growth, and significant prolongation of survival (median survival 77 days) in tumor-bearing NSG mice. Strikingly, 1,1-DEE simultaneously alleviates cancer-associated cachexia by preserving body weight. Mechanistically, our findings reveal a ROS–AMPK–centered signaling axis through which 1,1-DEE integrates tumor-selective cytotoxicity with systemic metabolic protection, highlighting a unified therapeutic strategy for targeting both tumor progression and cachexia in neuroblastoma. Full article

The diverse health benefits of lactic acid bacteria (LAB) have made them a focal point of research in the fields of food and health sciences. Furthermore, probiotics and postbiotics have been demonstrated to directly or indirectly influence food quality and human health. A substantial body of research has been dedicated to the antimicrobial activity of pro- and postbiotics; however, their antioxidant properties remain relatively unexplored. Although LAB are facultative anaerobes, there are several species that have the potential to undergo aerobic respiration, thereby being exposed to the action of reactive oxygen species (ROS). The resultant oxidative stress has been shown to damage all intracellular molecules, thus requiring the presence of antioxidants in order to counteract this effect. The present review discusses the peculiarities of respiration, the role of ROS, the antioxidant potential of LAB, and the mechanisms underlying their activity. Furthermore, the study explores the antioxidant capacity of probiotics and postbiotics, as well as their role in controlling oxidative stress. The objective of the present review is to provide an overview of the current research on the oxidative stress tolerance and antioxidant capacity of LAB and its impact on food. Full article

Soil hypoxia caused by waterlogging severely restricts kiwifruit growth, and screening waterlogging-tolerant rootstocks and analyzing their mechanisms are of great significance for industrial development. In this study, waterlogging-tolerant Actinidia valvata ‘Shuixiu’ was used as the test material and Actinidia chinensis ‘Hongyang’ as the control. Waterlogging stress was simulated artificially, and physiological measurements combined with transcriptome sequencing were used to explore its waterlogging tolerance regulatory characteristics based on respiratory metabolism. The results showed that the waterlogging tolerance of ‘Shuixiu’ was significantly better than that of ‘Hongyang’. It upregulated sucrose synthase and α/β-amylase genes and inhibited the continuous up-regulation of trehalose-6-phosphate synthase genes, leading to significant accumulation of glucose-6-phosphate, a key glycolytic substrate. Some members of glycolytic key gene families, such as glucose-6-phosphate isomerase and phosphofructokinase, were upregulated in ‘Shuixiu’, which increased phosphoglycerate kinase activity and accumulated 3-phosphoglyceric acid and pyruvate, ensuring efficient conversion of carbon sources to ATP. Some members of core tricarboxylic acid cycle gene families, such as pyruvate dehydrogenase and citrate synthase, were upregulated in ‘Shuixiu’, with significantly higher pyruvate dehydrogenase activity and acetyl coenzyme A content, maintaining partial aerobic respiration capacity. Some members of the alanine transaminase gene family were upregulated in ‘Shuixiu’ to enhance alanine fermentation, resulting in a significant reduction in root ethanol accumulation. This study clarified the core respiratory metabolic regulatory characteristics of kiwifruit in response to waterlogging and provided key targets and a theoretical basis for molecular breeding of waterlogging-tolerant rootstocks. Full article

Acoustic divergence is widely recognized as a key driver of speciation and niche differentiation in vocal animals. In echolocating horseshoe bats (Rhinolophus), the larynx is specialized for producing high-duty-cycle signals used in foraging, navigation, and species recognition. While the ecological role of echolocation is established, the molecular mechanisms regulating laryngeal frequency remain unclear. We compared the laryngeal transcriptomes of three closely related, sympatric Rhinolophus species with distinct resting frequencies (RFs): R. episcopus (~46 kHz), R. siamensis (~66 kHz), and R. osgoodi (~85 kHz). This comparison identified 511 differentially expressed genes. High-frequency species upregulated genes involved in cytoskeletal dynamics and muscle contraction, such as cell adhesion molecules and motor proteins, while low-frequency species upregulated genes related to cellular homeostasis and metabolic maintenance. Weighted gene co-expression network analysis revealed two RF-correlated modules: a high-frequency module enriched in aerobic respiration and carbon metabolism and a low-frequency module enriched in lipid metabolism. Protein–protein interaction analysis identified ACTC1, vital for muscle contraction, as a hub gene. Evolutionary analysis showed that ACTC1 is highly conserved, with no significant positive selection, indicating that transcriptional regulation, rather than coding-sequence divergence, is the primary driver of the observed functional differences. These findings suggest that RF variation likely results from transcriptional remodeling in laryngeal superfast muscles. This study provides the first transcriptomic evidence linking laryngeal gene expression with acoustic divergence and offers new insights into the genetic basis of bat echolocation. Full article

Fishes contribute to the biological carbon pump, yet their overall role remains poorly constrained due to the difficulty of obtaining direct metabolic measurements and, consequently, is poorly understood. Electron transport system (ETS) activity is commonly used as a proxy for potential respiration, but its application requires an appropriate relationship between respiration (R, measured as oxygen consumption MO₂) and ETS activity. Here, we examined the relationship between swimming activity, oxygen consumption, and ETS activity in juvenile Sparus aurata using swimming-tunnel respirometry. Oxygen consumption increased with swimming speed following a four-parameter sigmoidal model, whereas ETS activity remained independent of short-term changes in activity. Normalizing respiration by ETS produced R/ETS ratios ranging from 0.17 to 0.71, values consistent with those reported for zooplankton and micronekton. Lower ratios correspond to minimal aerobic demand and may represent quiescent behaviour, while higher ratios reflect elevated demands associated with active movement or feeding. These ratios are suggested for the assessment of respiration rates from ETS activity during diel vertical migration in the ocean to improve estimates of respiratory flux. However, methodological issues related to ETS activity in different body regions must be solved to enable reliable measurements. Full article

High-altitude grazing animals are continuously exposed to strong wind and low temperature, which challenge physiological homeostasis and energy metabolism. Improving living conditions and nutritional supplementation are two commonly used strategies. In this study, sixty 7-month-old Gangba sheep (initial body weight (BW) 21.00 ± 1.90 kg) were allocated to a 42-day trial with four groups (open-air sheepfold, mobile sheepfold, open-air sheepfold + supplementary feeding, mobile sheepfold + supplementary feeding) to investigate their effects on growth performance, serum parameters and gut microbiota in naturally grazing Gangba sheep. Mobile sheepfolds increased the temperature–humidity index (THI) and reducing the wind chill index (WCI) (p < 0.05). The sheep with mobile sheepfold showed higher serum total antioxidant capacity and lower levels of heat shock proteins HSP70 and HSP90 (p < 0.05), indicating alleviated stress. Supplementary feeding markedly increased final BW and average daily gain (p < 0.05). The interaction between sheepfold type and feeding supplementation showed increasing IgA levels in the open-air sheepfold with supplementary feeding group and increasing IL-4 levels in the mobile sheepfold with supplementary feeding group, while TNF-α concentrations were reduced in all three treatment groups (p < 0.05). Meanwhile, KB and FFAs were increased in the open-air sheepfold with supplementary feeding group but decreased in the mobile sheepfold with supplementary feeding group (p < 0.05). The mobile sheepfold also increased the Bacillota-to-Bacteroidota ratio, suggesting improved microbial community structure. Functional predictions showed enrichment of reductive acetogenesis and reduction in aerobic chemoheterotrophy and sulfur-related respiration pathways (p < 0.05). Moreover, key microbial genera were significantly correlated with THI and WCI (p < 0.05). Collectively, these results demonstrated that mobile sheepfold together with feeding supplementation improve stress responses, serum immune and lipid metabolic indicators, and potentially altered gut microbial composition and function, providing insights into host–microbiota interaction in extreme high-altitude environments. Full article

Pre-cooling can rapidly reduce the respiration intensity of fruit, helping extend its preservation period. This study investigates the effects of forced-air cooling with package treatment on fruit cooling and subsequent quality during storage. Moreover, a comparison was made between forced-air cooling and hydro-cooling in terms of fruit quality. Specifically, ‘Guiwei’ litchi fruit was treated with forced-air cooling at air velocities of 3, 6, and 10 m/s and hydro-cooling (5 °C), followed by storage at 3–5 °C for 18 days. Changes in cooling efficiency, pericarp moisture content, color, fruit firmness, weight loss, total soluble solids (TSS), and titratable acidity (TA) were monitored. The temperature of the forced-air-treated fruit first decreases faster and then slows down as the air velocity increases from 3 m/s to 10 m/s. Compared to forced-air cooling, hydro-cooling-treated fruit maintained better pericarp color, higher cooling rate, pericarp moisture content, and fruit firmness, but presented a lower total soluble solids (TSS) content, with no significant difference in titratable acidity (TA). The weight loss and aerobic respiratory depletion positively correlate with total soluble solid content and texture softening of litchi. The results provide a comprehensive reference for the selection of pre-cooling methods and the improvement of the postharvest industry. Full article