Acetic acid is indirectly involved in cell center metabolism, and acetic acid metabolism is the core of central metabolism, affecting and regulating the production of bacteriocin. Bacteriocin is a ...natural food preservative that has been used in the meat and dairy industries and winemaking. In this paper, the effects of acetic acid on bacteriocin produced by Gram-positive bacteria were reviewed. It was found that acetic acid in the undissociated state can diffuse freely through the hydrophobic layer of the membrane and dissociate, affecting the production, yield, and activity of bacteriocin. In particular, the effect of acetic acid on cell membranes is summarized. The link between acetic acid metabolism, quorum sensing, and bacteriocin production mechanisms is also highlighted.
Background This study aimed to explore the regulatory effect of anserine on HUVEC cell injury and thrombosis in deep venous thrombosis (DVT) rats, and to elucidate the underlying molecular ...mechanisms. Methods Non-targeted metabolomics data analyses were conducted using an ultra-performance liquid chromatography system Vanquish UHPLC and mass spectrometer to detect plasma metabolism profiles. The transcriptome sequencing and gene intervention experiments were performed to verify the regulatory effect. Further in vivo and in vitro experiments were performed. Enzyme-linked immunosorbent assay was used to detect the levels of P-selectin, E-selectin, and vWF, hematoxylin-eosin (HE) staining was performed to observe thrombotic and inflammatory cell infiltration, flow cytometry and TUNEL assays were performed to detect apoptosis, and qPCR and WB assays were conducted to determine the gene and protein expression. Results Anserine alleviated HUVECs injury, reduced adhesion molecule expression, and inflammation. It decreased P-selectin, E-selectin, vWF, THBD, TFPI levels, and apoptosis while promoting NOS3, ET-1, and NO release in HUVECs. In DVT rats, anserine reduced P-selectin, E-selectin, vWF, thrombosis, cell infiltration, apoptosis, and promoted NO release. Transcriptome sequencing and gene intervention confirmed anserine’s regulation of the PI3K-Akt pathway and coagulation via MYB. CARNMT1, a regulatory enzyme for anserine metabolism, increased anserine content, inhibiting coagulation, thrombosis, cell infiltration, and promoting NO release in rats. Conclusion This study confirmed anserine could alleviate DVT by improving the inflammatory response, inhibiting blood agglutination, and promoting vasodilation, providing new potential therapeutic targets, important scientific evidence for the development of DVT management, and new clues for an in-depth understanding of its molecular mechanisms.
An EPS produced by Weissella confusa H2 was purified through Sephadex G-100, and the preliminary structure characteristics and biological activities of H2 EPS were analyzed. Molecular mass of ...purified H2 EPS was 2.705 × 106 Da as measured with gel permeation chromatography (GPC). Composition of monosaccharides, nuclear magnetic resonance (NMR) spectroscopy spectroscopy and fourier transform infrared (FT-IR) showed that the EPS was a linear homopolysaccharide, mainly constituted of glucose and it is suggested that the EPS was dextran with α-(1 → 6) glycosidic bonds and a few α-(1 → 3) branches. Atomic force micrograph (AFM) and scanning electron microscopy (SEM) analysis of dextran further revealed sheets branched microstructure anchored with many irregular protuberances in aqueous solution. The XRD pattern reflected non-crystalline amorphous nature. In addition, the solubility, water-holding capacity, thermal property, rheological property and heavy metal chelating activity of the purified H2 dextran were determined. The dissolution percentage and water holding capacity of the dextran were 98.78 ± 1.37% and 426.03 ± 7.26%, respectively. The dextran exhibited good hydrophilicity, thermal stability and heavy metal chelating activity. Rheological studies exhibited rotational speed, pH, temperature, metal ions solutions dependent semiviscous nature. These results support its use as an additive in the food and environmental protection fields.
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To investigate the miRNA-21 over-expression in the acute kidney injury induced by sepsis, we developed a sepsis induced in vitro model by lip polysaccharide (LPS) and in vovo model by cecal ligation ...and puncture (CLP) surgery. LPS or CLP surgery induced kidney cell apoptosis increasing. However, the kidney injury indexes of miRNA groups which were transfected with miRNA-21 were significantly suppressed. In further study, the relative proteins expressions were evaluated to explain the miRNA-21 mechanism to improve sepsis induced kidney cell apoptosis. The results were shown that miRNA-21 over-expression had effects to protect kidney cell apoptosis induced by sepsis via PTEN/PI3K/AKT signaling pathway.
Increasing evidence suggests that the pathogenesis of type 2 diabetes mellitus (T2DM) is closely related to the gut microbiota. Polyphenols have been shown to alleviate T2DM, but the effects of
L. ...caerulea
L. polyphenols (LPs) on the gut microbiota and metabolites remain elusive. In this study, the inhibitory effects of fermented
L. caerulea
L. polyphenols (FLPs) and unfermented
L. caerulea
L. polyphenols (ULPs) on α-amylase and α-glucosidase and the impact of LP on the gut microbiota and metabolites were investigated. Furthermore, the relationship between the two was revealed through correlation analysis. The results showed that ULP and FLP had the highest inhibitory rates against α-amylase and α-glucosidase at 4 mg ml
−1
, indicating a strong inhibitory ability. In addition, LP plays a regulatory role in the concentration of short-chain fatty acids (SCFAs) and tends to restore them to their normal levels. LP reversed the dysbiosis of the gut microbiota caused by T2DM, as evidenced by an increase in the abundance of bacterial genera such as
Lactobacillus
,
Blautia
, and
Bacteroides
and a decrease in the abundance of bacterial genera such as
Escherichia-Shigella
and
Streptococcus
. Similarly, after LP intervention, the relationships among microbial species became more complex and interconnected. In addition, the correlation between the gut microbiota and metabolites was established through correlation analysis. These further findings clarify the mechanism of action of LP against T2DM and provide a new target for T2DM interventions.
Summary
To investigate the effects of Lactobacillus casei on Chinese sauerkraut fermentation, L. casei 11MZ‐5‐1 was inoculated into Chinese sauerkraut. Physicochemical indexes were measured, and the ...microbial dynamics during the fermentation were analysed by quantitative real‐time PCR (qRT‐PCR) and polymerase chain reaction‐denaturing gradient gel electrophoresis (PCR‐DGGE). The result showed that inoculation with L. casei 11MZ‐5‐1 lowered the pH of the fermentation system more rapidly than in the control model (CK). The content of vitamin C (VC) (44.64 ± 2.12 mg kg−1) was higher and nitrite (under 0.76 mg kg−1) was lower than CK (P < 0.05). The numbers of 16S rRNA gene copies in the experimental model (BA) were lower than in CK at the end fermentation time. According to the PCR‐DGGE analyses, 22 and 17 specific bands were detected in CK and BA, respectively. L. paracasei and L. casei were predominant during the fermentation in BA. The relative abundance and diversity indices of bacteria in BA were 8.23 ± 0.25 and 2.01 ± 0.06, respectively, lower than in the CK (P < 0.05). So, the L. casei 11MZ‐5‐1 inoculations could effectively inhibit the microbial diversity in the fermentation system. The fermented cabbage with L. casei 11MZ‐5‐1 was more favourably estimated by consumers in terms of colour, crispness, sourness, aroma, bitterness, stink, stale flavour and overall acceptability.
Lactobacillus casei 11MZ‐5‐1 as a starter was inoculated into Chinese sauerkraut. Physicochemical indexes and microbial dynamics were measured. The numbers of 16S rRNA gene copies in the control sample (CK) were lower than (P < 0.05) in inoc ulated sample (BA) during the first 11 days of fermentation. In the BA, the pH value was lower, the rapidly and Vc content were higher than CK (P < 0.05). Twenty two and 17 specific bands were detected in CK and BA by PCR‐DGGE analyses, respectively. L. paracasei and L. casei were predominant during the fermentation in BA. The relative abundance and diversity indices of bacteria in BA were lower than in the CK (P < 0.05). The L. casei 11MZ‐5‐1 inhibited the microbial diversity and improved the quality of Chinese sauerkraut.
Objectives
2,3-Butanediol (2,3-BD) is widely used in several chemical syntheses as well as the manufacture of plastics, solvents, and antifreeze formulations, and can be manufactured by microbial ...glucose fermentation. Conventional (2,3-BD) fermentation typically has low productivity, yield, and purity, and is expensive for commercial applications. We aimed to delete the lactate dehydrogenase and acetate kinase (
ldh
A and
ack
) genes in
Klebsiella pneumoniae
HD79 by using λRed homologous recombination technology, to eliminate by-products and thereby improve (2,3-BD) production. We also analyzed the resulting gene changes by using transcriptomics.
Results
The yield of (2,3-BD) from the mutant
Klebsiella
strain was 46.21 g/L, the conversion rate was 0.47 g/g, and the productivity was 0.64 g/L·h, which represented increases of 54.9%, 20.5%, and 106.5% respectively, compared to (WT) strains. Lactate and acetate decreased by 48.2% and 62.8%, respectively. Transcriptomics analysis showed that 4628 genes were differentially expressed (404 significantly up-regulated and 162 significantly down-regulated). Moreover, the (2,3-BD) operon genes were differentially expressed.
Conclusion
Our data showed that the biosynthesis of (2,3-BD) was regulated by inducers (lactate and acetate), a regulator (
Bud
R), and carbon flux. Elimination of acidic by-products by
ldh
A and
ack
knockdown significantly improved (2,3-BD) production. Our results provide a deeper understanding of the mechanisms underlying (2,3-BD) production, and form a molecular basis for the improvement this process by genetic modification in the future.
Glucansucrase (GS) belongs to the GH70 family, which not only can synthesize exopolysaccharides (EPSs) with different physicochemical properties through glucosyl transglycosylation (by hydrolyzing ...sucrose) but can also produce oligosaccharides. Different strains produce different GSs, which catalyze the synthesis of EPS with different glycosidic bond structures; these EPSs have different biological functions. As an important enzymatic tool, GS has great potential in health care medicine, biological materials, ecological protection, the food chemical industry, etc. GS is mainly produced by lactic acid bacteria (LAB), including Leuconostoc, Streptococcus, Lactobacillus, and Weissella species. With the elucidation of the crystal structure of GS and the advancement of genome sequencing technology, its synthesis reaction mechanism and specific structural characteristics are gradually becoming clear. This review summarizes the isolation, purification, physical and chemical properties, detection methods, sources, and applications of GS in order to provide a reference for the research and development of GS.
Background. Deep vein thrombosis (DVT) is the third most prevalent vascular disease worldwide. MicroRNAs (miRNAs) play regulatory roles in functions of endothelial progenitor cells (EPCs), which is ...becoming a promising therapeutic choice for thrombus resolution. Nevertheless, the role of miR-206 in EPCs is unclear. Methods. EPCs were isolated from the peripheral blood of patients with DVT. In DVT mouse models, DVT was induced by stenosis of the inferior vena cava (IVC). The levels of miR-206 and gap junction protein alpha 1 (GJA1) in EPCs and vascular tissues of DVT mice were detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The proliferation, migration, apoptosis, and angiogenesis were tested by cell counting kit-8 (CCK-8) assay, Transwell assay, flow cytometry analysis, and in vitro tube formation assay. The levels of autophagy-related proteins as well as the level of GJA1 in EPCs and vascular tissues were evaluated by western blotting. DVT formation in vivo was observed through hematoxylin-eosin (HE) staining. The expression of thrombus resolution markers, CD34 molecule (CD34) and matrix metallopeptidase 2 (MMP2), in the thrombi was measured by immunofluorescence staining. Results. miR-206 overexpression inhibited proliferation, migration, and angiogenesis and promoted apoptosis of EPCs, while miR-206 knockdown exerted an opposite effect on EPC phenotypes. Downregulation of GJA1, the target of miR-206, abolished the influence of miR-206 on EPC phenotypes. Furthermore, silencing of miR-206 suppressed the autophagy of EPCs via upregulating GJA1. miR-206 knockdown repressed thrombus formation, enhanced the homing ability of EPCs to the thrombosis site, and facilitated thrombus resolution in DVT mouse models. Additionally, miR-206 was upregulated while GJA1 was downregulated in vascular tissues of DVT mice. miR-206 knockdown elevated GJA1 expression in vascular tissues of DVT mice. The expression of miR-206 was negatively correlated with that of GJA1 in DVT mice. Conclusion. miR-206 knockdown upregulates GJA1 to inhibit autophagy of EPCs and then promote EPC proliferation, migration, and angiogenesis, thereby enhancing EPC homing to thrombi and facilitating thrombus resolution.
Although costunolide (Cos), a natural sesquiterpene compound isolated from various medicinal plants, exhibits antiproliferative and pro-apoptotic effects in diverse types of cancers, the mechanism ...associated with the anticancer property of Cos has not been elucidated. The present investigation was carried out to study the anticarcinogenic influence of Cos on kidney cancer cells. Several human renal cancer cell lines were used and biological and molecular studies were conducted. It was found that Cos significantly suppressed renal carcinoma cell growth
via
stimulation of apoptosis and autophagy in a concentration-dependent manner. Further studies revealed that Cos increased Bax/Bcl-2 ratio, decreased mitochondrial transmembrane potential (MMP), and enhanced cytoplasmic levels of cytochrome
c
, and activation of caspase-9, caspase-3, and cleaved PARP, resulting in cell apoptosis. The autophagy induced by Cos resulted from the formation of GFP-LC3 puncta and upregulation of LC3B II and Beclin-1 proteins. Compared with Cos treatment, the autophagy inhibitor 3-MA or ROS scavenger NAC significantly inhibited apoptosis and autophagy. Moreover, NAC and JNK-specific inhibitor SP600125 attenuated the effect of Cos. Taken together, Cos exerted autophagic and apoptotic effects on renal cancer through the ROS/JNK-dependent signal route. These findings suggest that Cos could be a beneficial anticarcinogenic agent.
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