Search Results (377)

Koshu wine, produced from the indigenous Japanese grape Vitis vinifera L. cv. Koshu exhibits a lower pH than other white wines, hindering malolactic fermentation (MLF) by lactic acid bacteria (LAB). Here, we aimed to isolate LAB strains capable of performing MLF under these challenging conditions to improve wine quality. Sixty-four Oenococcus oeni and one Lactobacillus hilgardii strain were isolated from Koshu grapes and wines that had undergone spontaneous MLF. MLF activity was assessed under varying pH, SO₂, and ethanol conditions in modified basal medium (BM) and Koshu model wine media. Expression of stress-related genes was analyzed using real-time PCR. Carbon source utilization was evaluated via API 50CH assays. All isolates degraded malic acid and produced lactic acid at 15 °C and pH 3.2 in BM without reducing sugars. Seven strains, all identified as O. oeni, demonstrated MLF activity at pH 3.0 in modified BM lacking added reducing sugars or tomato juice. Six wine-derived strains tolerated up to 12% ethanol, whereas the grape-derived strain was inhibited at 10%. In a synthetic Koshu wine model (13% ethanol, pH 3.0), wine-derived isolates exhibited higher MLF activity than commercial starter strains. In high-performing strains, mleA was upregulated, and most isolates preferred fructose, arabinose, and ribose over glucose. These findings suggest that indigenous O. oeni strains from Koshu wine possess unique stress tolerance and metabolic traits, making them promising candidates for region-specific MLF starter cultures that could enhance Koshu wine quality and terroir expression. Full article

Oxidative stress (OS) is a major concern in young poultry and livestock, prompting extensive research on OS models. This study aimed to systematically investigate the dynamic effects and temporal trends of OS induced with lipopolysaccharide (LPS) over time. Twenty-eight piglets were randomly divided into four groups and equally intraperitoneally injected with LPS at doses of 0 μg/kg (control), 50 μg/kg (L-LPS), 100 μg/kg (M-LPS) and 150 μg/kg (H-LPS) body weight, respectively. The results showed that total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD), and catalase (CAT) were decreased, while malondialdehyde (MDA), nitric oxide (NO), inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6), IL-1β, tumor necrosis factor-α (TNF-α), diamine oxidase (DAO) and D-lactic acid (D-LA) were increased in the M-LPS and H-LPS group on day 1 in comparison with the control group, but no differences were found among treatments on day 7. However, LPS treatments gave rise to varying degrees of pathological injury in the intestines, livers and spleens on day 7. Metabolomics analysis indicated that compared with the control group, glycyl-valine, histamine and lepidine F were decreased in the M-LPS group. Most differentially expressed metabolites were enriched in amino acid-related metabolism pathways on both day 1 and day 7. Microbiome analysis identified that Oscillibacter_sp._CAG:241 was decreased in the M-LPS group compared with the control group on day 1, while Bacteroides_thetaiotaomicron and Lactobacillus_amylovorus were reduced in the M-LPS group on day 7. Collectively, an LPS dose of 100 μg/kg body weight is optimal for inducing acute inflammation in Wuzhishan miniature pigs. These findings highlight the importance of considering both the duration of OS induction and the specific research objectives when establishing OS models. Full article

Lactiplantibacillus plantarum is a kind of common lactic acid bacteria, which plays an important role in the production of fermented foods. In general, the formation of biofilm is conducive to the adaptability of cells in the face of fierce competition and an increasingly harsh fermentation environment. In this work, optimum conditions for the formation of biofilm by L. plantarum were investigated, and scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) analysis showed the morphology of biofilm cells and 3D architecture of biofilm under different conditions, respectively. In addition, cells in the biofilms showed higher cell viability under heat stress, acid stress, and oxidative stress compared with planktonic cells. RNA-seq technology and TMT-based proteomic technology were employed to reveal the differential expression of profiles between biofilm cells and planktonic cells. The shelter provided by biofilm and the differential expression of genes and proteins involved in PTS, the TCA cycle, alanine, and teichoic acid biosynthesis may be involved in the formation of biofilm cells. The results presented in this study will help to understand the formation of biofilms in L. plantarum and regulate the industrial performance of cells in the food industry. Full article

Lacticaseibacillus rhamnosus J3205 was isolated from traditional fermented sauces and demonstrated potential probiotic properties. The strain exhibited high tolerance to simulated saliva (93.24% survival) and gastrointestinal conditions (69.95% gastric and 50.44% intestinal survival), along with strong adhesion capacity (58.25%) to intestinal epithelial cells. Safety assessments confirmed the absence of virulence and antibiotic resistance genes. Genomic analysis revealed stress-response genes and 34 insertion sequence (IS) elements, while proteomic profiling identified Pgk as a key enzyme in lactic acid production and SecY in oxidative stress resistance. Functionally, J3205 significantly reduces pro-inflammatory cytokines (TNF-α, IL-6, IL-1β) and enhances antioxidant markers (SOD, GSH) in vitro. These results position L. rhamnosus J3205 as a promising candidate for gut-health foods, anti-inflammatory nutraceuticals, and oxidative-stress therapeutics, warranting further in vivo validation. Full article

Due to the roles of oxidative stress, inflammation, and neurotransmitter imbalances in cognitive and mental dysfunction, we aimed to develop a functional drink with antioxidant and anti-inflammatory properties as well as the potential to support neurotransmitter balance for improved cognition and mental health. The Teng Mo, Fen Hong Mee, and Hong Chon Su guava varieties were screened for their polyphenol and flavonoid contents, antioxidant and anti-inflammatory effects, and suppressive effects on acetylcholinesterase (AChE), monoamine oxidase (MAO), GABA transaminase (GABA-T), and glutamate decarboxylase (GAD). Juice from the cultivar with the highest potential was selected and mixed with mint and honey syrups, pomelo-derived dietary fiber, ascorbic acid, agar, water, and fruit puree (pear/apple/orange) to create three guava jelly drink formulations. The formulation with pear puree showed the highest biological potential and was selected as the final product. It is rich in vitamin C, gallic acid, and dietary fiber, and provides approximately 37 Kcal/100 g. It also promotes the growth of lactic acid-producing bacteria in the culture. Thus, our drink shows the potential to reduce oxidative stress and inflammation, improve neurotransmitter regulation, and stimulate the gut–brain axis, thereby promoting cognition and mental wellness. However, clinical research is essential to confirm these potential benefits. Full article

Pediococcus pentosaceus, an important lactic acid bacterium in the brewing of Chinese Baijiu (liquor), usually encounters environmental stresses including ethanol and lactic acid, which severely impact cellular growth and metabolism. In this study, a combined physiological and omics analysis was employed to elucidate the response mechanisms of P. pentosaceus under ethanol and lactic acid stress conditions. The results showed that the biomass of cells decreased by about 40% under single-stress conditions and 70% under co-stress conditions. Analysis of the differentially expressed genes revealed that the cells adjusted various cellular processes to cope with environmental stresses, including modifications in cell wall synthesis, membrane function, and energy production pathways. Meanwhile, the increased expression of genes involved in DNA repair system and protein biosynthesis ensured the normal physiological function of cells. Notably, under ethanol stress, P. pentosaceus upregulated genes involved in unsaturated fatty acid biosynthesis, enhancing membrane stability and integrity. Conversely, under lactic acid stress, cells downregulated F-type ATPase, reducing H⁺ influx to maintain intracellular pH homeostasis. The metabolomic analysis revealed DNA damage under co-stress conditions and further validated the transcriptomic results. Our findings elucidate the molecular and physiological strategies of P. pentosaceus under acid and ethanol stress, providing a foundation for optimizing fermentation processes and enhancing microbial resilience in industrial settings. Full article

Antibiotic overuse has contributed to the emergence of multidrug-resistant (MDR) bacteria, posing a serious public health threat. Pets may act as reservoirs of MDR bacteria, with the potential to transmit these pathogens to humans. This study aimed to identify probiotic alternatives to antibiotics by isolating and evaluating lactic acid bacteria (LAB) from feline milk. In addition to conventional in vitro assessments such as growth kinetics, adhesion ability, safety, and antipathogenic activity, this study also evaluated the antioxidant capacity and production of beneficial metabolites. Three LAB strains were isolated from feline milk, including two strains of Lactobacillus plantarum (M2 and M3) and one strain of Weissella confusa (M1). Resistance assays revealed that strains M2 and M3 exhibited high survival rates under stress conditions, including exposure to bile salts, acidic environments, artificial intestinal and gastric juice. Notably, strain M3 demonstrated strong auto-aggregation ability (73.39%) and high hydrophobicity toward trichloromethane (62.16%). It was also nonhemolytic and susceptible to various β-lactam antibiotics. Furthermore, strain M3 exhibited potent antimicrobial activity in both co-aggregation and Oxford cup assays. Overall, L. plantarum M3 displayed superior probiotic properties, suggesting its potential as an adjunct or alternative to antibiotics in managing MDR bacterial infections in cats. Full article

Biodegradable vascular stents (BVSs) face challenges related to inadequate mechanical strength, which can lead to adverse clinical outcomes. Improving the mechanical behavior of biodegradable vascular stents through structural design has been extensively explored. However, the corresponding effects of these mechanical enhancements on degradation characteristics remain under-investigated. The present work focuses on examining how different stent design strategies affect the mechanical behavior and degradation characteristics of poly (lactic acid) (PLA) stents. The commercial PLA stent DESolve was adopted, and nine modified stents were constructed based on the geometrical configuration of the DESolve stent. The mechanical properties of the modified stents during radial crimping and three-point bending simulations were thoroughly studied. The degradation dynamics of the stents were characterized by four indices (i.e., mean number average molecular weight, residual volume fraction, mean von Mises stress, and stent diameter). The results indicated that both the widening ratio and direction affected the mechanical performance of the stents by increasing the radial stiffness and radial strength, minimizing recoil%, and decreasing the bending flexibility. Although the widening direction had a relatively minor influence on stent degradation, the associated increase in material volume contributed to an improved volumetric integrity and enhanced lumen preservation. This study established a theoretical basis for evaluating both the mechanical and degradation behaviors of PLA stents, offering valuable insights for future structural design optimization. Full article

Caragana korshinskii Kom. (CKB), widely cultivated in Inner Mongolia, China, has potential for silage feed development due to its favorable nutritional characteristics, including a crude protein content of 14.2% and a neutral detergent fiber content below 55%. However, its vascular bundle fiber structure limits the efficiency of lactic acid conversion and negatively impacts silage quality, which can be improved through mechanical crushing. Currently, conventional crushing equipment generally suffers from uneven particle size distribution, high energy consumption, and low processing efficiency. In this study, a layered aggregate model was constructed using the discrete element method (DEM), and the Hertz–Mindlin with Bonding contact model was employed to characterize the heterogeneous mechanical properties between the epidermis and the core. Model accuracy was enhanced through reverse engineering and a multi-particle-size filling strategy. Key parameters were optimized via a Box–Behnken experimental design, with a core normal stiffness of 7.37 × 10¹¹ N·m⁻¹, a core shear stiffness of 9.46 × 10¹⁰ N·m⁻¹, a core shear stress of 2.52 × 10⁸ Pa, and a skin normal stiffness of 4.01 × 10⁹ N·m⁻¹. The simulated values for bending, tensile, and compressive failure forces had relative errors of less than 10% compared to experimental results. The results showed that rectangular hammers, due to their larger contact area and more uniform stress distribution, reduced the number of residual bonded contacts by 28.9% and 26.5% compared to stepped and blade-type hammers, respectively. Optimized rotational speed improved dynamic crushing efficiency by 41.3%. The material exhibited spatial heterogeneity, with the mass proportion in the tooth plate impact area reaching 43.91%, which was 23.01% higher than that in the primary hammer crushing area. The relative error between the simulation and bench test results for the crushing rate was 6.18%, and the spatial distribution consistency reached 93.6%, verifying the reliability of the DEM parameter calibration method. This study provides a theoretical basis for the structural optimization of crushing equipment, suppression of circulation layer effects, and the realization of low-energy, high-efficiency processing. Full article

Bioconversion of cortisone leads to the synthesis of the steroid derivatives 1,9β,17,21-tetrahydroxy-4-methyl-19-nor-9β-pregna-1,3,5(10)-trien-11,20-dione (SCA) and 1,9β,17,20β,21-pentahydroxy-4-methyl-19-nor-9β-pregna-1,3,5(10)-trien-11-one (SCB), which have been identified as biologically active molecules in affections associated with oxidative stress and inflammation, particularly in the skin and eye. To date, the synthesis of SCA and SCB can only be achieved through a biocatalytic approach, following a biotransformation process catalyzed by Rhodococcus rhodnii DSM 43960, a synthetic pathway that adheres to the principles of green chemistry. To further enhance the sustainability of this process, this study demonstrated that SCA and SCB can be synthesized by bioconversion in a complex medium derived from a dual upcycling process involving olive leaves (UOLM). By formulating a medium based on olive leaves, a by-product derived from the previously reported biotechnological production of lactic acid, and using a concentration of 10% v/v UOLM and 1 g/L cortisone at pH 7.5, bioconversion yields of 90 ± 4.5% were achieved, with a predominance of SCB. Investigations into the addition of supplements, such as tryptone, peptone, and corn steep liquor (CSL), to assess potential improvements in yield were conducted, but no significant positive variations were observed. For the first time, bioactive steroids were synthesized from a medium obtained through a dual upcycling process of olive leaves, introducing an innovative method that opens new possibilities for the investigation of a second generation of biosteroids synthesized from lignocellulosic feedstocks. Full article

The protein fraction of slaughterhouse blood remains underutilized primarily due to challenges associated with its instability during processing and storage. This study aimed to develop stable bovine blood plasma gels using selected lactic acid bacteria and flaxseed oil cake flour. Various lactic acid bacteria strains were incorporated at concentrations of 5–20% (w/w), and gel properties such as pH, gelation time, yield stress, and freeze–thaw syneresis were evaluated. Optimal gelation was achieved at 20% inoculum, producing fibrin networks with yield stresses (372 Pa) comparable to recalcified controls (410 Pa), but accompanied by high serum loss and undesired acidic aromas at higher bacterial densities. Incorporating 5% hydrated flaxseed oil cake flour successfully reduced syneresis below 10%, improved water-holding capacity (135%), and prevented development of off-flavors, demonstrating beneficial interactions between flaxseed polysaccharides and blood plasma proteins. Thus, combining a 20% mixed lactic starter with 5% flaxseed cake flour yielded a stable plasma gel suitable for meat product applications, balancing rapid gel formation, high moisture retention, desirable rheological properties, and neutral sensory characteristics. Full article

High-temperature stress is one of the main limiting factors for the cultivation and management of cool-season creeping bentgrass (Agrostis stolonifera). The objectives of the current study were to compare physiological changes in heat-tolerant PROVIDENCE and heat-sensitive PENNEAGLE and further identify differential organic metabolites associated with thermotolerance in leaves. Two cultivars were cultivated under optimal conditions (23/19 °C) and high-temperature stress (38/33 °C) for 15 days. Heat stress significantly reduced leaf relative water content, chlorophyll content, and photochemical efficiency, and also resulted in severe oxidative damage to PROVIDENCE and PENNEAGLE. Heat-tolerant PROVIDENCE exhibited 10% less water deficit, 11% lower chlorophyll loss, and significantly lower oxidative damage as well as better cell membrane stability compared with PENNEAGLE under heat stress. Metabolomic analysis further found that PROVIDENCE accumulated more sugars (fructose, tagatose, lyxose, ribose, and 6-deoxy-D-glucose), amino acids (norleucine, allothreonine, and glycine), and other metabolites (lactic acid, ribitol, arabitol, and arbutin) than PENNEAGLE. These metabolites play positive roles in energy supply, osmotic adjustment, antioxidant, and membrane stability. Heat stress significantly decreased the accumulation of tricarboxylic acid cycle-related organic acids in two cultivars, resulting in a metabolic deficit for energy production. However, both PROVIDENCE and PENNEAGLE significantly up-regulated the accumulation of stigmasterol related to the stability of cell membrane systems under heat stress. The current findings provide a better understanding of differential thermotolerance in cool-season turfgrass species. In addition, the data can also be utilized in breeding programs to improve the heat tolerance of other grass species. However, the current study only focused on physiological and metabolic responses to heat stress between two genotypes. It would be better to utilize molecular techniques in future studies to better understand and validate differential heat tolerance in creeping bentgrass species. Full article

The linear polymer polyphosphate (polyP) is found across all three domains of life and fulfills diverse physiological functions, including phosphorus storage, chaperone activity, and stress tolerance. In bacteria, polyP synthesis is catalyzed by polyphosphate kinase (Ppk), whereas its degradation is carried out by exopolyphosphatases (Ppx). Intracellular polyP levels are determined by the balance between these opposing enzymatic activities, although the regulatory mechanisms governing this balance remain incompletely understood. In higher eukaryotes, polyP participates in diverse physiological processes from cell signaling to blood clotting. In relation to this, polyP from Levilactobacillus brevis has been identified as a protective factor against intestinal damage in a mouse model of acute colitis. Subsequent evidence has confirmed that polyP can confer beneficial effects on human intestinal health, prompting an increased interest in the production of polyP by probiotic lactic acid bacteria. Furthermore, polyP is extensively used in the food industry to enhance food quality, preservation, and nutritional value. This review summarizes the current knowledge on polyP metabolism in these bacteria and explores its functional properties and potential applications. Full article

As an important aquaculture species, the marine snail Babylonia areolata is frequently subjected to fluctuation in dissolved oxygen concentration during farming and transportation processes. In the present study, we investigated the metabolic rates, transcription, and enzyme level responses of juvenile B. areolata exposed to long-term stress (144 h). The results showed that the mortality rate of juvenile B. areolata was higher in the 0.5 mg O₂/L group compared to the 2 mg O₂/L group. During the hypoxic stress period, both oxygen consumption and ammonia excretion rates were observed to be lower in juvenile B. areolata than those in the control group. As hypoxic stress duration prolonged, juvenile B. areolata demonstrated significantly elevated activities of pyruvate kinase (PK) and alkaline phosphatase (AKP), alongside reduced activities of lactic dehydrogenase (LDH), acid phosphatase (ACP), and superoxide dismutase (SOD). Significant changes in the expression levels of PK and LDH genes were observed during the hypoxic stress. The expression levels of ACP and SOD genes were significantly downregulated, while juvenile B. areolata exhibited elevated AKP gene expression levels under 0.5 mg O₂/L. Our findings suggest that under long-term exposure to hypoxia, B. areolata failed to maintain energy homeostasis and suffered biochemical disruptions, leading to a reduction in survival. The mortality rate of B. areolata can be substantially decreased by ensuring that transportation time does not exceed 48 h. Full article

During the solid-state brewing process of traditional Chinese Baijiu, lactic acid is the most abundant organic acid, which inhibits the growth and metabolism of Saccharomyces cerevisiae. To reveal the lactic acid tolerance mechanism of S. cerevisiae, the growth, metabolic performance, and antioxidant enzyme activity of S. cerevisiae NCUF309.5-44 and S. cerevisiae NCUF309.5 were measured under 4% (v/v) lactic acid stress. Additionally, whole-genome re-sequencing and transcriptomic analyses were performed to identify genetic variations and differentially expressed genes between the two strains under lactic acid stress. The results showed that, compared to the original strain, S. cerevisiae NCUF309.5-44 could adapt to the lactic acid stress faster, with a superior utilization rate of reducing sugar and a 6.43-fold higher ethanol production at 16 h. The strain primarily activated the GSH/GPx system, resulting in a 37.29% lower intracellular ROS content. A total of 1087 SNPs and 698 InDels were found between the strains, with 384 genes significantly upregulated and 254 genes downregulated in the S. cerevisiae NCUF309.5-44 under lactic acid stress. S. cerevisiae NCUF309.5-44 responded to lactic acid stress by activating the pheromone response pathway and the cell wall integrity pathway. Meanwhile, the capacity of strains to maintain the cell membrane and proton extrusion was strengthened. Additionally, its glycolysis/gluconeogenesis metabolism was also enhanced. All these mechanisms collectively contributed to improving the lactic acid tolerance of S. cerevisiae NCUF309.5-44. These findings not only enhanced our understanding of lactic acid tolerance mechanisms of S. cerevisiae NCUF309.5-44 but also paved the way for the application of this strain in optimizing Baijiu production. Full article