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This research aims to elucidate the physiological mechanisms behind the accidental acquisition of high-concentration cesium ions (Cs+) tolerance of Escherichia coli and apply this understanding to develop bioremediation technologies. Bacterial Cs+ resistance has attracted attention, but its physiological mechanism remains largely unknown and poorly understood. In a prior study, we identified the Cs+/H+ antiporter TS_CshA in Microbacterium sp. TS-1, resistant to high Cs+ concentrations, exhibits a low Cs+ affinity with a Km value of 370 mM at pH 8.5. To enhance bioremediation efficacy, we conducted random mutagenesis of TS_cshA using Error-Prone PCR, aiming for higher-affinity mutants. The mutations were inserted downstream of the PBAD promoter in the pBAD24 vector, creating a mutant library. This was then transformed into E. coli-competent cells. As a result, we obtained a Cs+-resistant strain, ZX-1, capable of thriving in 400 mM CsCl—a concentration too high for ordinary E. coli. Unlike the parent strain Mach1™, which struggled in 300 mM CsCl, ZX-1 showed robust growth even in 700 mM CsCl. After 700 mM CsCl treatment, the 70S ribosome of Mach1™ collapsed, whereas ZX-1 and its derivative ΔZX-1/pBR322ΔAp remained stable. This means that the ribosomes of ZX-1 are more stable to high Cs+. The inverted membrane vesicles from strain ZX-1 showed an apparent Km value of 28.7 mM (pH 8.5) for Cs+/H+ antiport activity, indicating an approximately 12.9-fold increase in Cs+ affinity. Remarkably, the entire plasmid isolated from ZX-1, including the TS_cshA region, was mutation-free. Subsequent whole-genome analysis of ZX-1 identified multiple SNPs on the chromosome that differed from those in the parent strain. No mutations in transporter-related genes were identified in ZX-1. However, three mutations emerged as significant: genes encoding the ribosomal bS6 modification enzyme RimK, the phage lysis regulatory protein LysB, and the flagellar base component protein FlgG. These mutations are hypothesized to affect post-translational modifications, influencing the Km value of TS_CshA and accessory protein expression. This study unveils a novel Cs+ resistance mechanism in ZX-1, enhancing our understanding of Cs+ resistance and paving the way for developing technology to recover radioactive Cs+ from water using TS_CshA-expressing inverted membrane vesicles.

The sensitivity of freshness indicator labels/films has become an important research direction of intelligent food packaging. In this study, a high-sensitivity indicator film containing gelatin and Fe2＋ was prepared by electrospinning using blueberry anthocyanins as the indicator and zein as the matrix for monitoring fish freshness. The validity and sensitivity of the indicator film for detecting the freshness of silver carp were tested and the potential mechanism was elucidated. The results of pH sensitivity, ammonia sensitivity and anthocyanin release showed that the addition of gelatin and Fe2+ improved the sensitivity of the indicator film to pH and ammonia, and contributed to better binding of the anthocyanins in the film. There was a strong correlation between the color response (P = (L* + a* + b* + R + G + B)/a*) of the film and the content of total volatile basic nitrogen (TVB-N) content in fish meat as a freshness indicator (R2 > 0.98). In conclusion, the prepared indicator film can effectively monitor fish freshness, and the hydrogen bond interactions between anthocyanins and gelatin/Fe2+ may affect the color response characteristics and sensitivity of the indicator film.

Heating is a vital step in the gelation of surimi. Conventional water bath heating (WB) has the advantages of easy operation and low equipment requirements. However, the slow heat penetration during WB may lead to poor gel formation or gels prone to deterioration, especially with one-step heating. The two-step WB is time-consuming, and a large amount of water used tends to cause environmental problems. This review focuses on key factors affecting the quality of surimi gels in various heating technologies, such as surimi protein structure, chemical forces, or the activity of endogenous enzymes. In addition, the relationships between these factors and the gel performance of surimi under various heating modes are discussed by analyzing the heating temperature and heating rate. Compared with WB, the gel performance can be improved by controlling the heating conditions of microwave heating and ohmic heating, which are mainly achieved by changing the molecular structure of myofibrillar proteins or the activity of endogenous enzymes in surimi. Nevertheless, the novel thermal technologies still face several limitations and further research is needed to realize large-scale industrial production. This review provides ideas and directions for developing heat-induced surimi products with excellent gel properties. [ABSTRACT FROM AUTHOR]

This research aims to elucidate the physiological mechanisms behind the accidental acquisition of high-concentration cesium ions (Cs+) tolerance of Escherichia coli and apply this understanding to develop bioremediation technologies. Bacterial Cs+ resistance has attracted attention, but its physiological mechanism remains largely unknown and poorly understood. In a prior study, we identified the Cs+/H+ antiporter TS_CshA in Microbacterium sp. TS-1, resistant to high Cs+ concentrations, exhibits a low Cs+ affinity with a Km value of 370  mM at pH 8.5. To enhance bioremediation efficacy, we conducted random mutagenesis of TS_cshA using Error-Prone PCR, aiming for higheraffinity mutants. The mutations were inserted downstream of the PBAD promoter in the pBAD24 vector, creating a mutant library. This was then transformed into E. coli-competent cells. As a result, we obtained a Cs+-resistant strain, ZX-1, capable of thriving in 400  mM CsCl—a concentration too high for ordinary E. coli. Unlike the parent strain Mach1™, which struggled in 300  mM CsCl, ZX-1 showed robust growth even in 700  mM CsCl. After 700  mM CsCl treatment, the 70S ribosome of Mach1™ collapsed, whereas ZX-1 and its derivative ΔZX1/pBR322ΔAp remained stable. This means that the ribosomes of ZX-1 are more stable to high Cs+. The inverted membrane vesicles from strain ZX-1 showed an apparent Km value of 28.7  mM (pH 8.5) for Cs+/H+ antiport activity, indicating an approximately 12.9-fold increase in Cs+ affinity. Remarkably, the entire plasmid isolated from ZX-1, including the TS_cshA region, was mutationfree. Subsequent whole-genome analysis of ZX-1 identified multiple SNPs on the chromosome that differed from those in the parent strain. No mutations in transporter-related genes were identified in ZX-1. However, three mutations emerged as significant: genes encoding the ribosomal bS6 modification enzyme RimK, the phage lysis regulatory protein LysB, and the flagellar base component protein FlgG. These mutations are hypothesized to affect posttranslational modifications, influencing the Km value of TS_CshA and accessory protein expression. This study unveils a novel Cs+ resistance mechanism in ZX-1, enhancing our understanding of Cs+ resistance and paving the way for developing technology to recover radioactive Cs+ from water using TS_CshAexpressing inverted membrane vesicles. [ABSTRACT FROM AUTHOR]

Liver cirrhosis remains a significant global public health concern, with liver transplantation standing as the foremost effective treatment currently available. Therefore, investigating the pathogenesis of liver cirrhosis and developing novel therapies is imperative. Mitochondrial dysfunction stands out as a pivotal factor in its development. This study aimed to elucidate the relationship between mitochondria dysfunction and liver cirrhosis using bioinformatic methods to unveil its pathogenesis. Initially, we identified 460 co-expressed differential genes (co-DEGs) from the GSE14323 and GSE25097 datasets, alongside their combined datasets. Functional analysis revealed that these co-DEGs were associated with inflammatory cytokines and cirrhosis-related signaling pathways. Utilizing weighted gene co-expression network analysis (WCGNA), we screened module genes, intersecting them with co-DEGs and oxidative stress-related mitochondrial genes. Two algorithms (least absolute shrinkage and selection operator (LASSO) regression and SVE-RFE) were then employed to further analyze the intersecting genes. Finally, COX7A1 and IFI27 emerged as identifying genes for liver cirrhosis, validated through a receiver operating characteristic (ROC) curve analysis and related experiments. Additionally, immune infiltration highlighted a strong correlation between macrophages and cirrhosis, with the identifying genes (COX7A1 and IFI27) being significantly associated with macrophages. In conclusion, our findings underscore the critical role of oxidative stress-related mitochondrial genes (COX7A1 and IFI27) in liver cirrhosis development, highlighting their association with macrophage infiltration. This study provides novel insights into understanding the pathogenesis of liver cirrhosis. [ABSTRACT FROM AUTHOR]

Liver fibrosis, acute liver injury or liver failure, liver tumors, and immune rejection after liver transplantation are common clinical liver diseases. Immune responses are the key to determining the prognosis of liver diseases. Liver transplantation could be the last resort for patients with liver failure. However, the use of liver transplantation is limited because of the scarcity of organ donors, immunological rejection in recipients, and high cost. Mesenchymal stem cells (MSCs) are pluripotent adult stem cells with extensive anti‐inflammatory and immunomodulation effects. MSCs can be effectively used for treating liver diseases but without the limitations that are associated with liver transplantation. Therefore, several clinical trials have utilized MSCs for the treatment of refractory liver diseases and the related mechanism is increasingly being elucidated. We have mainly summarized the recent studies that focus on the immunomodulation mechanism of MSC therapy in liver diseases. Further, we have presented our insights on the prospects of using MSCs in the treatment of liver diseases. [ABSTRACT FROM AUTHOR]

Summary: This research investigated the dynamic changes and correlations of protease activity, material texture and flavour compounds during the fermentation (13 days) of crucian (Carassius auratus). Mixed starter fermentation (Enterococcus rivorum and Enterococcus lactis) and natural fermentation were used for the study. Results showed that the protease activity, TCA‐soluble protein and flavour substances were increased with fermentation time and were higher in the mixed fermentation group. The results of relative odour activity value showed that some aldehydes played a major role in the flavour of the product, such as octanal, nonanal and (E)‐2‐nonenal. The correlation analysis showed that protease activity and material texture (hardness and chewiness) had a significantly positive correlation with many flavour compounds (octanal, nonanal, glutamic acid, etc.). This work will provide a theoretical reference for the application of mixed starter cultures and for improving the quality of suanyu by increasing protease activity and changing the texture of the material. [ABSTRACT FROM AUTHOR]

Salt is a necessary condition to produce a surimi product that is based on the gelation of salt-soluble myofibrillar proteins. Recently, there has been a growing concern among consumers to consume healthy foods due to the threat of several chronic diseases caused by an unhealthy diet. Methods of reducing salt content out of concern for health issues caused by excessive sodium intake may affect the gel properties of surimi, as can many health-oriented food additives. Several studies have investigated different strategies to improve the health characteristics of surimi products without decreasing gel properties. This review reports recent developments in this area and how the gel properties were successfully maintained under reduced-salt conditions and the use of additives. This review of recent studies presents a great deal of progress made in the health benefits of surimi and can be used as a reference for further development in the surimi product processing industry. [ABSTRACT FROM AUTHOR]

Spectral conversion has been widely applied in the field of luminescence and is potentially beneficial for photovoltaic solar cells. However, more was said than done for the down‐conversion effect in the past, and quite a number of existing reports overclaimed the observed performance enhancement from down conversion either by wrongly identifying the contributions or by unfairly comparing with an inappropriate reference. Herein, Ce‐doped Y3Al5O12 ceramics with suitable absorption and photoluminescence properties are chosen as the down‐conversion material for Cu(In,Ga)Se2 (CIGS) solar cells. By properly designing optical structures to integrate the down‐conversion material with the CIGS solar cell, the fluorescent photons are efficiently guided to the CIGS absorber layer in addition to eliminating the scattering and maintaining the antireflection (AR) for incident light. The Y3Al5O12:Ce3+ ceramic down converter on CIGS solar cells can bring an enhancement of 0.53 mA cm−2 to the short‐circuit current density solely from down conversion, which is responsible for the major increase in conversion efficiency from 18.5% to 19.0%. A positive down‐conversion effect is demonstrated over AR layer‐coated CIGS solar cells without misclaiming contributions from other accompanied effects or jeopardizing any other accompanying effects. [ABSTRACT FROM AUTHOR]

Microbial contamination is one of the most common food safety issues that lead to food spoilage and foodborne illness, which readily affects the health of the masses as well as gives rise to huge economic losses. In this study, Channa argus was used as a source of antimicrobial agent that was then analyzed by untargeted metabolomics for its antibacterial mechanism against Staphylococcus aureus. The results indicated that the skin mucus extract of C. argus had great inhibitory action on the growth of S. aureus, and the morphology of S. aureus cells treated with the skin mucus extract exhibited severe morphological damage under scanning electron microscopy. In addition, metabolomics analysis revealed that skin mucus extract stress inhibited the primary metabolic pathways of S. aureus by inducing the tricarboxylic acid cycle and amino acid biosynthesis, which further affected the normal physiological functions of biofilms. In conclusion, the antimicrobial effect of the skin mucus extract is achieved by disrupting cell membrane functions to induce an intracellular metabolic imbalance. Hence, these results conduce to amass novel insights into the antimicrobial mechanism of the skin mucus extract of C. argus against S. aureus. [ABSTRACT FROM AUTHOR]

The combined effects of l -arginine (Arg) and oxidized caffeic acid (OCF) treatment under different salt concentrations on gelling properties of bighead carp (Aristichthys nobilis) surimi gels were investigated. The results showed that the improvement of gel strength and water-holding capacity (WHC) of low-salt (0.5%) surimi gels could be obtained by adding Arg at various levels (0.1–0.4%) rather than OCF (0.1–0.9%, based on protein content). However, the gel strength and WHC of the low-salt surimi gel added with low-dose (0.1%) Arg alone were still far lower than that of regular-salt (3.0%) control. Whereas the significant improvements in low-salt surimi gels could be achieved when 0.1% Arg was combined with various levels of OCF, especially in combination with 0.5% OCF (LC-A-O). The water distribution in LC-A-O was markedly improved and its β-sheet structure content was significantly increased compared with the low-salt control (P < 0.05). Moreover, a denser and more uniform network structure of LC-A-O was obtained, which was probably due to much stronger and more intra-molecular cross-linking of proteins, via the formation of new adducts between OCF and surimi proteins. Hence, the combined treatment of Arg and OCF showed a potential for improving the gel properties of low-salt surimi. • The combination of Arg and OCF increased β-sheet content of the surimi protein. • Arg increased protein solubility, which helped OCF react with proteins. • Protein-OCF adducts help to improve the low salt surimi gel properties. • Arg and OCF played synergistic roles in enhancing low salt surimi gel properties. [ABSTRACT FROM AUTHOR]

• Ordered structures of myosin were converted to disordered structures by L-Arg. • The effect was more obvious on rod-rod cross-linking than head-head aggregation. • Increasing pH induced by L-Arg increased the electrostatic repulsion of myosin. • The cationic L-Arg interacted with anionic groups on the myosin at neutral pH. • Heat-induced phase separation of myosin was ameliorated by L-Arg. This investigation aimed to study the potential mechanism of L-arginine (L-Arg) on the heat-induced phase separation phenomenon of myosin from the perspective of conformational changes of myosin. L-Arg ameliorated the phase separation of myosin after a two-step heating procedure via suppression of heat-induced aggregation of myosin. The effect of L-Arg on the heating of myosin at high temperatures (75–85 °C) was more pronounced than that in the setting stage (35–45 °C), suggesting that the ameliorative effects of L-Arg on the heat-induced phase separation of myosin are mainly attributed to the inhibition of rod-rod cross-linking between denatured myosin molecules. Additionally, L-Arg without pH modification exhibited an increased ability to suppress the gelation of myosin compared with pH modification, indicating that both pH effects and the particular structure of L-Arg play noticeable roles in the suppression of myosin gelation. Far-UV circular dichroism, intrinsic fluorescence spectroscopy and differential scanning calorimetry demonstrated that L-Arg induced the absence of ordered secondary structures of myosin molecules, especially β-sheets, and thus generated a looser protein structure, which may represent the dominant suppression mechanisms of L-Arg on the heat-induced aggregation of myosin. This work provided support for the use of L-Arg as a food additive, and the results of this study will be attractive to the meat and beverage products. [ABSTRACT FROM AUTHOR]

Physicochemical and functional properties of two types of Jerusalem artichoke powder (JAP), freeze-dried powder (FDP) and oven-dried powder (ODP), and their potential application in emulsion-type sausages were evaluated in this study. The total phenolic content of FDP was higher than that of ODP. Again, FDP exhibited higher water-holding capacity, emulsion activity, emulsion stability, oil-binding capacity and gel-forming capacity values compared to ODP. TG/DSC analysis of FDP and ODP showed both of them were thermally stable at 150 °C. As a substitute of corn starch, the addition of FDP or ODP could reduce cooking loss and expressible water, increased the moisture content, oxidative stability and enhanced the anti-microbial properties of the emulsion-type sausage. The addition of FDP (9%) and ODP (9%) to the emulsion-type sausage was promising comparable to additions of 3% and 6%. This could be attributed to the inulin contents in the JAP. Scanning electron microscopy also showed that the addition of FDP or ODP in sausage formation led to a difference in the sausages. This study indicated that JAP (FDP and ODP) improved the processing properties of the emulsion-type sausage. [ABSTRACT FROM AUTHOR]

• Arg and ultrasound played synergistic roles in enhancing stability of the emulsion. • Arg strengthened the effect of ultrasound in the adsorption of interfacial myosin. • Arg and ultrasound induced the exposure of aromatic and aliphatic amino acid. • Arg and ultrasound increased the ordered structures content of interfacial myosin. • Protein gelation network of emulsion droplet formed under Arg and ultrasound. The effects of l -arginine (Arg)-assisted ultrasonic treatment on the molecular and interfacial characteristics of myosin and emulsifying properties of the emulsion were evaluated to ascertain the underlying mechanism in improving the emulsion stability. Ultrasonication induced the exposure of residues of native myosin, which was increased by the addition of Arg (40 mM). Furthermore, in terms of emulsions containing Arg, the higher the ultrasonication intensity was, the greater the increase in adsorbed protein (from 15.43 ± 0.28% to 50.49 ± 1.65%) and π value, and the decrease in droplet sizes (from 4098 nm to 2324 nm) (P < 0.05). Moreover, the increase in the ordered structures of interfacial myosin induced by Arg and ultrasonication favoured the formation of a protein gelation network. In summary, Arg-assisted ultrasonic treatment improved the stability of the emulsion by inducing the exposure of native myosin and facilitating the formation of ordered structures of interfacial myosin. [ABSTRACT FROM AUTHOR]

• 124 components in fermented barley aqueous extract were identified by UPLC-HRMS. • PCA distinguished the samples and visualized the process with fermentation time. • Metabolomics revealed the change of components in barley with fermentation time. • Phytochemicals and metabolites were released and accumulated by L. plantarum dy-1. • Indole-3-lactic acid, etc. were identified as significant increasing components. Fermentation has been considered as effective tools to promote the functional properties of cereals. In this paper, barley flour was fermented with Lactobacillus plantarum dy-1 (L. plantarum dy-1) and the main components in the fermented barley aqueous extracts were identified using by ultra-high performance liquid chromatography tandem with high resolution mass spectrometry (UPLC-HRMS), and investigated by metabolomics strategy involved on chemometrics. The barley extracts were prepared at the fermentation time of 0, 4, 8, 12, 16, 20, 24, 28 h, respectively and a total of 124 compounds were detected in the samples. Principal component analysis (PCA) was performed and the results indicated that the fermentation process became to slow down from 16 h until terminated. During fermentation, saccharides, amino acids, nucleosides, and some organic acids decreased, while lipids and bioactive molecules in barley were released and metabolites were accumulated by L. plantarum dy-1. Meanwhile, partial least squares discrimination analysis (PLS-DA) was performed for revealing the characteristic components in fermented barley aqueous extracts, including some functional molecules such as indole-3-lactic acid, phenyllactic acid, homovanillic acid and cafestol, etc., which provided the roles of them and the basis for further investigation on the functional bioactivities and application. [ABSTRACT FROM AUTHOR]