Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 64
Filtrar
1.
JACS Au ; 4(9): 3413-3420, 2024 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-39328756

RESUMO

The formation of a hexagonal diamond represents one of the most intriguing questions in materials science. Under shock conditions, the graphite basal plane tends to slide and pucker to form diamond. However, how the shock strength determines the phase selectivity remains unclear. In this work, using a DFT-trained carbon global neural network model, we studied the shock-induced graphite transition. The poor sliding caused by scarce sliding time under high-strength shock leads to metastable hexagonal diamond with an orientation relationship of (001)G//(100)HD+[010]G//[010]HD, while under low-strength shock due to long sliding distance cubic diamond forms with the orientation (001)G//(111)CD+[100]G//[110]CD, unveiling the strength-dependent graphite transition mechanism. We for the first time provide computational evidence of the strength-dependent graphite transition from first-principles, clarifying the long-term unresolved shock-induced hexagonal diamond formation mechanism and the structural source of the strength-dependent trend, which facilitates the hexagonal diamond synthesis via controlled experiment.

2.
J Am Chem Soc ; 146(29): 20221-20229, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-38985464

RESUMO

Nanoscale secondary ion mass spectrometry (NanoSIMS) makes it possible to visualize elements and isotopes in a wide range of samples at a high resolution. However, the fidelity and quality of NanoSIMS images often suffer from distortions because of a requirement to acquire and integrate multiple image frames. We developed an optical flow-based algorithm tool, NanoSIMS Stabilizer, for all-channel postacquisition registration of images. The NanoSIMS Stabilizer effectively deals with the distortions and artifacts, resulting in a high-resolution visualization of isotope and element distribution. It is open source with an easy-to-use ImageJ plugin and is accompanied by a Python version with GPU acceleration.

3.
Int J Cosmet Sci ; 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38922913

RESUMO

OBJECTIVE: The objective of this work was to understand how triglyceride plant oils can deliver strength and softness benefits to hair by their penetration. These plant oils are complex mixtures of TAGs, so the initial studies performed were with pure TAGs and then these data compared to plant oils and their measured TAG compositions. METHODS: LC-MS was used to identify the di and triglycerides in coconut oil, Camellia oleifera oil and safflower seed oil. Penetration of these plant oils and pure individual triglycerides was measured by a differential extraction method. Cross-sections of oils treated with 13C-labelled triolein were studied by NanoSIMS to visualize location of triglyceride inside hair. Fatigue strength was measured using constant stress to generate a survival distribution. Models of the lipid-rich cell membrane complex (CMC) were created with the equimolar ratio of 18-methyl-eicosanoic acid (MEAS), palmitic acid (C16:0) and oleic acid (C18:1). RESULTS: Penetration of the individual pure TAGs was confirmed for all chain lengths and degree of unsaturation tested with higher penetration for shorter chain lengths and unsaturated fatty acids. Detailed compositional analysis of selected plant oils showed a wide variety of TAGs and penetration was also demonstrated for these oils. NanoSIMS and modelling confirmed these TAGs are penetrating the lipid-rich CMC of hair and are interacting with the fatty acids that make up the CMC. All plant oils delivered a fatigue strength improvement by penetration into the CMC and it is proposed that these oils prevent formation and/or propagation of flaws in the CMC network that leads to breakage. CONCLUSIONS: Many plant oils with a wide range of triglyceride compositions can penetrate into hair and NanoSIMS data confirmed these oils partition into the lipid-rich cell membrane complex. Penetration studies of individual TAGs shown to be present in these oils confirmed TAGs of varying chain length can penetrate and there is a correlation between increased penetration efficacy and shorter chain lengths and presence of unsaturation in the fatty acid chains. All the oils studied delivered single fibre fatigue strength benefits.


OBJECTIF: L'objectif de ce travail était de comprendre comment les huiles végétales à base de triglycérides peuvent apporter aux cheveux des bienfaits en termes de résistance et de douceur grâce à leur pénétration. Ces huiles végétales sont des mélanges complexes de TAG, donc les études réalisées initiales ont porté sur des TAG purs et ces données ont été comparées à des huiles végétales et leurs compositions en TAG mesurées. MÉTHODES: La LC­MS a été utilisée pour identifier les di­ et triglycérides dans l'huile de noix de coco, l'huile de Camellia oleifera et l'huile de graines de carthame. La pénétration de ces huiles végétales et des triglycérides individuels purs a été mesurée par une méthode d'extraction différentielle. Des coupes transversales d'huiles traitées avec de la trioléine marquée au C13 ont été étudiées par NanoSIMS pour visualiser l'emplacement des triglycérides à l'intérieur des cheveux. La résistance à la fatigue a été mesurée à l'aide d'une sollicitation constante pour générer une distribution de la survie. Des modèles du complexe de membrane cellulaire riche en lipides (CMC) ont été créés avec le rapport équimolaire en acide 18­méthyleicosanoïque (MEAS), acide palmitique (C16:0) et acide oléique (C18:1). RÉSULTATS: La pénétration des TAG purs individuels a été confirmée pour toutes les longueurs de chaîne et le degré d'insaturation a été testé avec une pénétration plus élevée pour les chaînes plus courtes et les acides gras insaturés. Une analyse détaillée de la composition de certaines huiles végétales a montré une grande variété de TAG et la pénétration a également été démontrée pour ces huiles. Le NanoSIMS et la modélisation ont confirmé que ces TAG pénètrent dans la CMC riche en lipides des cheveux et interagissent avec les acides gras qui composent le CMC. Toutes les huiles végétales ont produit une amélioration de la résistance à la fatigue par pénétration dans le CMC et il est proposé que ces huiles préviennent la formation et/ou la propagation de défauts dans le réseau CMC qui entraînent une rupture. CONCLUSIONS: De nombreuses huiles végétales avec un large éventail de compositions de triglycérides peuvent pénétrer dans les cheveux et les données du NanoSIMS ont confirmé que ces huiles se divisent en complexe de membrane cellulaire riche en lipides. Les études de pénétration des TAG individuels qui se sont avérés présents dans ces huiles ont confirmé que les TAG de longueur de chaîne variable peuvent pénétrer et il existe une corrélation entre l'augmentation de l'efficacité de pénétration et les longueurs de chaîne plus courtes et la présence d'une insaturation dans les chaînes d'acides gras. Toutes les huiles étudiées ont montré des bienfaits en matière de résistance à la fatigue pour une seule fibre.

4.
Nat Commun ; 15(1): 4677, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38824146

RESUMO

Electron microscopy (EM) revolutionized the way to visualize cellular ultrastructure. Volume EM (vEM) has further broadened its three-dimensional nanoscale imaging capacity. However, intrinsic trade-offs between imaging speed and quality of EM restrict the attainable imaging area and volume. Isotropic imaging with vEM for large biological volumes remains unachievable. Here, we developed EMDiffuse, a suite of algorithms designed to enhance EM and vEM capabilities, leveraging the cutting-edge image generation diffusion model. EMDiffuse generates realistic predictions with high resolution ultrastructural details and exhibits robust transferability by taking only one pair of images of 3 megapixels to fine-tune in denoising and super-resolution tasks. EMDiffuse also demonstrated proficiency in the isotropic vEM reconstruction task, generating isotropic volume even in the absence of isotropic training data. We demonstrated the robustness of EMDiffuse by generating isotropic volumes from seven public datasets obtained from different vEM techniques and instruments. The generated isotropic volume enables accurate three-dimensional nanoscale ultrastructure analysis. EMDiffuse also features self-assessment functionalities on predictions' reliability. We envision EMDiffuse to pave the way for investigations of the intricate subcellular nanoscale ultrastructure within large volumes of biological systems.

5.
World J Clin Oncol ; 15(4): 540-547, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38689622

RESUMO

BACKGROUND: Immunotherapy have demonstrated promising outcomes in patients with high microsatellite instability (MSI) (MSI-H) metastatic colorectal cancer. However, the comparative effectiveness of Immunotherapy and chemotherapy for patients with low MSI (MSI-L), and microsatellite stable (MSS) metastatic colorectal cancer remains unclear. AIM: To investigate immunotherapy vs chemotherapy for treatment of MSI-L/MSS metastatic colorectal cancer, and to evaluate the success of immunotherapy against chemotherapy in managing MSI-H metastatic colorectal cancer during a follow-up of 50 months. METHODS: We conducted a retrospective cohort study using the National Cancer Database (NCDB) to evaluate the overall survival (OS) of patients with metastatic colorectal cancer treated with immunotherapy or chemotherapy. The study population was stratified by MSI status (MSI-H, MSI-L, and MSS). Multivariable Cox proportional hazard models were used to assess the association between treatment modality and OS, adjusting for potential confounders. RESULTS: A total of 21951 patients with metastatic colorectal cancer were included in the analysis, of which 2358 were MSI-H, and 19593 were MSI-L/MSS. In the MSI-H cohort, immunotherapy treatment (n = 142) was associated with a significantly improved median OS compared to chemotherapy (n = 860). After adjusting for potential confounders, immunotherapy treatment remained significantly associated with better OS in the MSI-H cohort [adjusted hazard ratio (aHR): 0.57, 95% confidence interval (95%CI): 0.43-0.77, P < 0.001]. In the MSS cohort, no significant difference in median OS was observed between immunotherapy treatment and chemotherapy (aHR: 0.94, 95%CI: 0.69-1.29, P = 0.715). CONCLUSION: In this population-based study using the NCDB, immunotherapy treatment was associated with significantly improved OS compared to chemotherapy in patients with MSI-H metastatic colorectal cancer, but not in those with MSI-L/MSS metastatic colorectal cancer. Further studies are warranted to determine the optimal therapeutic approach for patients with MSI-L/MSS metastatic colorectal cancer.

6.
Foods ; 12(15)2023 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-37569114

RESUMO

This study investigated the effects of different cold plasma treatment conditions on the lipid oxidation kinetics of tilapia fillets. The results indicated that increasing the voltage and prolonging the treatment time of cold plasma could cause an increase in the peroxide value and thiobarbituric acid-reactive substance values of the fillets. The changes in the primary and secondary oxidation rates of the lipids in the fillets under different treatment conditions were consistent with zero-order reaction kinetics. The analysis of the fitting of the Arrhenius equation showed that the effect of treatment voltage on the activation energy of lipid oxidation was higher than that of treatment time. When the voltage was higher than 64.71 kV, the activation energy of the primary oxidation of lipids was greater than that of secondary oxidation. Within 0-5 min, the activation energy of primary oxidation first increased then decreased, and was always greater than that of secondary oxidation. Therefore, the primary lipid oxidation of tilapia was more sensitive to the treatment conditions of cold plasma.

7.
J Dig Dis ; 24(5): 321-331, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37409681

RESUMO

OBJECTIVES: Postponed open necrosectomy or minimally invasive intervention has become the treatment option for necrotizing pancreatitis. Nevertheless, several studies point to the safety and efficacy of early intervention for necrotizing pancreatitis. Therefore, we conducted a systematic review and meta-analysis to compare clinical outcomes of acute necrotizing pancreatitis between early and late intervention. METHODS: Literature search was performed in multiple databases for articles that compared the safety and clinical outcomes of early (<4 weeks from the onset of pancreatitis) versus late intervention (≥4 weeks from the onset of pancreatitis) for necrotizing pancreatitis published up to August 31, 2022. The meta-analysis was performed to determine pooled odds ratio (OR) of mortality rate and procedure-related complications. RESULTS: Fourteen studies were included in the final analysis. For open necrosectomy intervention, the overall pooled OR of mortality rate with the late intervention compared with early intervention was 7.09 (95% confidence interval [CI] 2.33-21.60; I2 = 54%; P = 0.0006). For minimally invasive intervention, the overall pooled OR of mortality rate with the late intervention compared with early intervention was 1.56 (95% CI 1.11-2.20; I2 = 0%; P = 0.01). The overall pooled OR of pancreatic fistula with the late minimally invasive intervention compared with early intervention was 2.49 (95% CI 1.75-3.52; I2 = 0%; P < 0.00001). CONCLUSION: These results showed the benefit of late interventions in patients with necrotizing pancreatitis in both minimally invasive procedures and open necrosectomy. Late intervention is preferred in the management of necrotizing pancreatitis.


Assuntos
Pancreatite Necrosante Aguda , Humanos , Pancreatite Necrosante Aguda/cirurgia , Drenagem/métodos , Resultado do Tratamento , Fístula Pancreática
8.
Int J Mol Sci ; 24(7)2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37047577

RESUMO

Excess ammonium imposes toxicity and stress response in cyanobacteria. How cyanobacteria acclimate to NH4+ stress is so far poorly understood. Here, Synechocystis sp. PCC6803 S2P homolog Slr1821 was identified as the essential regulator through physiological characterization and transcriptomic analysis of its knockout mutant. The proper expression of 60% and 67% of the NH4+ activated and repressed genes, respectively, were actually Slr1821-dependent since they were abolished or reversed in ∆slr1821. Synechocystis 6803 suppressed nitrogen uptake and assimilation, ammonium integration and mobilization of other nitrogen sources upon NH4+ stress. Opposite regulation on genes for assimilation of nitrogen and carbon, such as repression of nitrogen regulatory protein PII, PII interactive protein PirC and activation of carbon acquisition regulator RcbR, demonstrated that Synechocystis 6803 coordinated regulation to maintain carbon/nitrogen homeostasis under increasing nitrogen, while functional Slr1821 was indispensable for most of this coordinated regulation. Additionally, slr1821 knockout disrupted the proper response of regulators and transporters in the ammonium-specific stimulon, and resulted in defective photosynthesis as well as compromised translational and transcriptional machinery. These results provide new insight into the coordinated regulation of nutritional fluctuation and the functional characterization of S2Ps. They also provide new targets for bioengineering cyanobacteria in bioremediation and improving ammonium tolerance in crop plants.


Assuntos
Compostos de Amônio , Synechocystis , Synechocystis/genética , Synechocystis/metabolismo , Compostos de Amônio/metabolismo , Nitrogênio/metabolismo , Carbono/metabolismo , Proteínas de Bactérias/metabolismo , Homeostase , Aclimatação , Peptídeo Hidrolases/metabolismo , Regulação Bacteriana da Expressão Gênica
9.
Int J Mol Sci ; 23(24)2022 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-36555789

RESUMO

Proteasome is a large proteolytic complex that consists of a 20S core particle (20SP) and 19S regulatory particle (19SP) in eukaryotes. The proteasome degrades most cellular proteins, thereby controlling many key processes, including gene expression and protein quality control. Proteasome dysfunction in plants leads to abnormal development and reduced adaptability to environmental stresses. Previous studies have shown that proteasome dysfunction upregulates the gene expression of proteasome subunits, which is known as the proteasome bounce-back response. However, the proteasome bounce-back response cannot explain the damaging effect of proteasome dysfunction on plant growth and stress adaptation. To address this question, we focused on downregulated genes caused by proteasome dysfunction. We first confirmed that the 20SP subunit PBE is an essential proteasome subunit in Arabidopsis and that PBE1 mutation impaired the function of the proteasome. Transcriptome analyses showed that hypoxia-responsive genes were greatly enriched in the downregulated genes in pbe1 mutants. Furthermore, we found that the pbe1 mutant is hypersensitive to waterlogging stress, a typical hypoxic condition, and hypoxia-related developments are impaired in the pbe1 mutant. Meanwhile, the 19SP subunit rpn1a mutant seedlings are also hypersensitive to waterlogging stress. In summary, our results suggested that proteasome dysfunction downregulated the hypoxia-responsive pathway and impaired plant growth and adaptability to hypoxia stress.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Citoplasma/metabolismo , Regulação da Expressão Gênica de Plantas , Hipóxia , Complexo de Endopeptidases do Proteassoma/genética , Complexo de Endopeptidases do Proteassoma/metabolismo
10.
Foods ; 11(17)2022 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-36076891

RESUMO

In order to investigate the effects of high voltage atmospheric cold plasma (HVACP) treatment on the number of microorganisms in and the quality of Trachinotus ovatus during refrigerator storage, fresh fish was packaged with gases CO2:O2:N2 (80%:10%:10%) and treated by HVACP at 75 kV for 3 min; then, the samples were stored at 4 ± 1 °C for nine days. The microbial numbers, water content, color value, texture, pH value, thiobarbituric acid reactive substance (TBARS), and total volatile base nitrogen (TVB-N) values of the fish were analyzed during storage. The results showed the growth of the total viable bacteria (TVB), psychrophilic bacteria, Pseudomonas spp., H2S-producing bacteria, yeast, and lactic acid bacteria in the treated samples was limited, and they were 1.11, 1.01, 1.04, 1.13, 0.77, and 0.80 log CFU/g-1 lower than those in the control group after nine days of storage, respectively. The hardness, springiness, and chewiness of the treated fish decreased slowly as the storage time extended, and no significant changes in either pH or water content were found. The lightness (L*) value increased and the yellowness (b*) value decreased after treatment, while no changes in the redness (a*) value were found. The TBARS and TVB-N of the treated samples increased to 0.79 mg/kg and 21.99 mg/100 g, respectively, after nine days of refrigerator storage. In conclusion, HVACP can limit the growth of the main microorganisms in fish samples effectively during nine days of refrigerator storage with no significant negative impact on their quality. Therefore, HVACP is a useful nonthermal technology to extend the refrigerator shelf-life of Trachinotus ovatus.

11.
J Am Chem Soc ; 144(16): 7414-7421, 2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35420809

RESUMO

Identifying ordering in non-crystalline solids has been a focus of natural science since the publication of Zachariasen's random network theory in 1932, but it still remains as a great challenge of the century. Literature shows that the hierarchical structures, from the short-range order of first-shell polyhedra to the long-range order of translational periodicity, may survive after amorphization. Here, in a piece of AlPO4, or berlinite, we combine X-ray diffraction and stochastic free-energy surface simulations to study its phase transition and structural ordering under pressure. From reversible single crystals to amorphous transitions, we now present an unambiguous view of the topological ordering in the amorphous phase, consisting of a swarm of Carpenter low-symmetry phases with the same topological linkage, trapped in a metastable intermediate stage. We propose that the remaining topological ordering is the origin of the switchable "memory glass" effect. Such topological ordering may hide in many amorphous materials through disordered short atomic displacements.

12.
Bioresour Technol ; 346: 126513, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34890818

RESUMO

Advances in microbial enzyme technology offer a significant opportunity for developing low-energy bioconversion solutions for industrial wastes as inexpensive feedstocks for useful products. In this short communication, two agro-food industrial wastes, chicken feather powder (CFP) and okara, were converted into peptides by a Bacillus licheniformis mutant using solid-state fermentation (SSF). The optimum SSF conditions for okara to CFP ratio, inoculum size, and time were 0.7 (7:10), 15%, and 90 h, respectively, which produced 185.99 mg/g peptides, with 910.12 U/g keratinase activity and 85.03% antioxidant scavenging activity. Compared to okara, CFP with mutant strain showed 11.28% higher keratinase activity and produced higher amounts of peptides (5.51%).


Assuntos
Bacillus licheniformis , Bacillus , Bacillus/genética , Bacillus licheniformis/genética , Fermentação , Resíduos Industriais , Peptídeos
13.
Appl Biochem Biotechnol ; 194(4): 1546-1565, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34806139

RESUMO

Keratinase is one of the important proteases, which is widely used for converting keratin of the keratinaceous materials into various value-added products. In this study, a popular keratinase producer, Bacillus licheniformis PWD-1, was exposed to ultraviolet (UV) and He-Ne laser irradiations to develop high keratinase-producing mutants. Laser irradiation showed a higher lethality of cells (94%) than UV treatment (92%), whereas laser treatment required a longer time (75 min) than UV treatment (20 min). A total of 58 mutants were selected from 176 isolates to study protein and keratinase production capability of the mutants. The highest keratin-to-casein (K:C) ratio (1.43) was exhibited by LU11 mutant, which was obtained from the combined laser and UV irradiations. The purified keratinase (65 kDa) of LU11 showed 40% yield 1.7-fold purity, while the respective value for wild enzyme was 29% and 1.3-fold. Both enzymes showed optimal activity at 55 ℃ and pH 8, with a Z value of 15.78 ℃ for LU11 and 19.72 ℃ for wild strain. The Vmax and specific constant (Kcat/Km) of the mutant enzyme were 357.17 U/ml and 33.11 min-1 mM-1, respectively, which were significantly higher than the respective values of wild enzyme (102.04 U/ml and 28.36 min-1 mM-1).


Assuntos
Bacillus licheniformis , Bacillus licheniformis/genética , Bacillus licheniformis/metabolismo , Concentração de Íons de Hidrogênio , Queratinas , Mutagênese , Peptídeo Hidrolases/metabolismo
14.
Int J Food Microbiol ; 358: 109402, 2021 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-34547531

RESUMO

The quorum sensing (QS) inhibition effect of methyl N-methylanthranilate (MMA) from Pericarpium Citri Reticulatae Chachiensis against foodborne pathogen Pseudomonas aeruginosa was reported for the first time. MMA effectively attenuated QS related virulence factors production and biofilm formation, while suppressed expression of a dozen of QS related genes. Untargeted LC-MS metabolomics revealed 108 significantly altered metabolites after MMA treatment. They indicated that MMA addition reduced the efficiency of TCA cycle and antioxidant systems, disturbed amino acid and nucleotide metabolism, increased unsaturated fatty acid and decreased peptidoglycan components, which might ultimately attenuate P. aeruginosa pathogenicity and restrain biofilm formation. Physiological characterization confirmed the compromised membrane integrity and increased intracellular oxidative stress after MMA treatment. Furthermore, metabolomics data implied that MMA inhibition on QS might exert through disrupting QS autoinducer PQS biosynthesis, which was supported by molecular docking. Our data indicated that MMA could be used as a novel QS inhibitor and anti-biofilm agent to improve food safety. It also provided new insight in the possible underlying inhibition mechanism of MMA and the response of P. aeruginosa to MMA.


Assuntos
Pseudomonas aeruginosa , Percepção de Quorum , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/farmacologia , Biofilmes , Metabolômica , Simulação de Acoplamento Molecular , Fatores de Virulência , ortoaminobenzoatos
15.
Microorganisms ; 9(6)2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-34200041

RESUMO

Pericarpium Citri Reticulatae 'Chachiensis' (PCR-Chachiensis), the pericarps of Citri Reticulatae Blanco cv. Chachiensis, is a food condiment and traditional medicine in southeast and eastern Asia. Its rich and various bacterial community awaits exploration. The present study is the first report on probiotic screening and characterization of bacteria from PCR-Chachiensis. Based on 64 culturable bacterial isolates, 8 strains were screened out to have great survival in the simulated gastrointestinal stressful condition, being nonhemolytic and without biogenic amine formation. They were identified by 16S rRNA gene sequencing as two Bacillus, three Lactobacillus, and three strains from Bacillales. Their probiotic properties, cholesterol-lowering potential and carbohydrate utilization capability were further investigated. Though these eight strains all displayed distinct cholesterol removal potential, Bacillus licheniformis N17-02 showed both remarkable cholesterol removal capability and presence of bile salt hydrolase gene, as well as possessing most of the desirable probiotic attributes. Thus, it could be a good probiotic candidate with hypocholesterolemic potential. Bacillus megaterium N17-12 displayed the widest carbohydrate utilization profile and the strongest antimicrobial activity. Hence, it was promising to be used as a probiotic in a host and as a fermentation starter in fermented food or feed.

16.
Food Res Int ; 125: 108624, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31554059

RESUMO

The dried and aged pericarps of Citri Reticulatae are condiments and medicinal products in southeast and eastern Asia for hundreds of years, among which Pericarpium Citri Reticulatae 'Chachiensis' (PCR-C) is the premium one with obvious health benefits. In order to explore the microbiota in PCR-C and their relationship with the chemical components during aging, culture-independent methods were applied to investigate PCR-C microbiota for the first time. Here in different PCR-C samples, 16S rRNA gene amplicon sequencing revealed common central bacterial community, which were absent or only accounted for small proportion in fresh pericarps or jute bag controls. Bacillus and Lactococcus were the top two dominant genera in PCR-C with acidic pH (4.06-4.51) and low moisture (11.48%-19.13%). Several OTUs were found to closely relate with specific compositions in essential oils and phenolics, such as d-limonene and nobiletin, which contributed to PCR-C flavor and quality. As the first study to reveal the central bacterial communities in PCR-C, it provides new insights to improve the quality and aging process of traditional Pericarpium Citri Reticulatae, and lays foundation for functional characterization of the microbes within.


Assuntos
Citrus/microbiologia , Condimentos/microbiologia , Medicamentos de Ervas Chinesas , Frutas/microbiologia , Bacillus/isolamento & purificação , Bactérias/classificação , Bactérias/isolamento & purificação , China , Flavonas/análise , Flavonoides/análise , Alimentos em Conserva/microbiologia , Frutas/química , Lactococcus/isolamento & purificação , Limoneno/análise , Óleos Voláteis/análise , Fenóis/análise
17.
Biotechnol Bioeng ; 116(12): 3333-3348, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31502661

RESUMO

Considerable attention has been given to the development of robust fermentation processes, but microbial contamination and phage infection remain deadly threats that need to be addressed. In this study, a robust Escherichia coli BL21(DE3) strain was successfully constructed by simultaneously introducing a nitrogen and phosphorus (N&P) system in combination with a CRISPR/Cas9 system. The N&P metabolic pathways were able to express formamidase and phosphite dehydrogenase in the host cell, thus enabled cell growth in auxotrophic 3-(N-morpholino)propanesulfonic acid medium with formamide and phosphite as nitrogen and phosphorus sources, respectively. N&P metabolic pathways also allowed efficient expression of heterologous proteins, such as green fluorescent protein (GFP) and chitinase, while contaminating bacteria or yeast species could hardly survive in this medium. The host strain was further engineered by exploiting the CRISPR/Cas9 system to enhance the resistance against phage attack. The resultant strain was able to grow in the presence of T7 phage at a concentration of up to 2 × 107 plaque-forming units/ml and produce GFP with a yield of up to 30 µg/109 colony-forming units, exhibiting significant advantages over conventional engineered E. coli. This newly engineered, robust E. coli BL21(DE3) strain therefore shows great potential for future applications in industrial fermentation.


Assuntos
Bacteriófago T7 , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/genética , Engenharia Metabólica , Microrganismos Geneticamente Modificados/crescimento & desenvolvimento , Microrganismos Geneticamente Modificados/genética , Sistemas CRISPR-Cas , Escherichia coli/virologia , Redes e Vias Metabólicas
18.
Int J Mol Sci ; 20(14)2019 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-31337051

RESUMO

Coccomyxa subellipsoidea C-169 (C-169) is an oleaginous microalga which is promising for renewable biofuel production. MicroRNAs (miRNAs), as the pivotal modulators of gene expression at post-transcriptional level, are prospective candidates for bioengineering practice. However, so far, no miRNA in C-169 has been reported and its potential impact upon CO2 supplementation remains unclear. High-throughput sequencing of small RNAs from C-169 cultured in air or 2% CO2 revealed 124 miRNAs in total, including 118 conserved miRNAs and six novel ones. In total, 384 genes were predicted as their potential target genes, 320 for conserved miRNAs and 64 for novel miRNAs. The annotated target genes were significantly enriched in six KEGG pathways, including pantothenate and CoA biosynthesis, C5-branched dibasic acid metabolism, 2-oxocarboxylic acid metabolism, butanoate metabolism, valine, leucine and isoleucine biosynthesis and alpha-linolenic acid metabolism. The miRNAs' target genes were enriched in lipid metabolism as well as RNA-interacting proteins involved in translation, transcription and rRNA processing. The pioneering identification of C-169 miRNAs and analysis of their putative target genes lay the foundation for further miRNA research in eukaryotic algae and will contribute to the development of C-169 as an oleaginous microalga through bioengineering in the future.


Assuntos
Clorófitas/genética , Regulação da Expressão Gênica , MicroRNAs/genética , Interferência de RNA , Clorófitas/metabolismo , Biologia Computacional/métodos , Metabolismo Energético , Redes Reguladoras de Genes , MicroRNAs/química , Família Multigênica
19.
Food Res Int ; 100(Pt 2): 19-30, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28888440

RESUMO

The demand from consumer for safe and nutritious berry and berry products has promoted the rapid development of non-conventional processing technologies. This review summarizes the recent advances of thermal and non-thermal processing technologies in berry and berry products, including microwave, ohmic heating, high pressure processing, irradiation, dense phase carbon dioxide, ultrasonic processing, pulsed electric field, ozone, membrane processing technologies, cold plasma, and hydrothermodynamic cavitation. These technologies individually or in combination have shown great potential for extraction, sterilization, drying, concentration and deacidfication. They could decrease processing time and temperature, improve processing efficiency and minimize nutritional losses, as well as reduce energy consumption. Given the nutritional benefits of anthocyanins and other polyphenols in berry, their content and compositional change during processing were highlighted, as well as the primarily studies of the underlying mechanisms. The advantage and limitation of these technologies are also discussed along with the perspective insight of their future development.


Assuntos
Suplementos Nutricionais , Manipulação de Alimentos/métodos , Frutas/química , Extratos Vegetais/química , Temperatura , Antioxidantes/química , Dessecação , Manipulação de Alimentos/instrumentação , Irradiação de Alimentos/métodos , Qualidade dos Alimentos , Frutas/efeitos da radiação , Benefícios do Seguro , Micro-Ondas , Valor Nutritivo , Gases em Plasma , Polifenóis/química , Pressão , Esterilização , Ultrassom/métodos
20.
Food Res Int ; 100(Pt 1): 873-884, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28873762

RESUMO

To explore the comprehensive phenolic profile of mulberry (Morus alba L.) fruit and reveal the novel anti-diabetic constituents, mulberry polyphenols (MP) were fractionated through gradient ethanol elution and subjected to composition and bioactivity analysis. Forty-seven phenolic compounds were identified and quantified through UHPLC-HR-ESI-TOF-MS/MS, including twenty-one newly identified compounds such as delphinidin 3-rutinoside-5-glucoside and cyanidin 3-rutinoside dimer. The antioxidant activity and anti-diabetic potential of fractionated MP were analyzed in vitro and ex vivo with HepG2 and pancreatic ß-cell RIN-m5F. Hierarchical cluster analysis and Pearson correlation coefficients revealed compounds such as syringic acid and galloylcyanidin-glycoside contributed most to inhibit α-glucosidase activity. Quercetin and cyanidin-glycosides were essential for cellular antioxidant activity. Dihydroquercetin and 1,5-dicaffeoylquinic acid were newly identified and validated as the main contributors after rutin to protect RIN-m5F cells against glucotoxicity. Such findings suggest the promising role of MP for type II diabetics and lay the foundation of further utilization and investigation.


Assuntos
Hipoglicemiantes , Morus/química , Extratos Vegetais/química , Polifenóis , Animais , Antocianinas/análise , Antocianinas/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Glucose/metabolismo , Glucosídeos/análise , Glucosídeos/química , Células Hep G2 , Humanos , Hipoglicemiantes/análise , Hipoglicemiantes/química , Hipoglicemiantes/farmacologia , Polifenóis/análise , Polifenóis/química , Polifenóis/farmacologia , Ratos , Espectrometria de Massas em Tandem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA