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1.
Food Microbiol ; 122: 104563, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38839237

RESUMO

Thermosonication (UT) prestress treatments combining with varied fermentation patterns has been revealed as an effective method to regulate post-acidification as exerted by Lactobacillus delbrueckii subsp. bulgaricus (L. delbrueckii), but sono-biochemical controlling mechanisms remain elusive. This study employed physiological and transcriptomic analysis to explore the response mechanism of L. delbrueckii to UT-induced microstress (600 W, 33 kHz, 10 min). UT stress-induced inhibition of acidification of L. delbrueckii during (post)-fermentation was first confirmed, relying on the UT process parameters such as stress exposure duration and UT power. The significantly enhanced membrane permeability in cells treated by 600 W for 10 min than the microbes stressed by 420 W for 20 min suggested the higher dependence of UT-derived stresses on the treatment durations, relative to the ultrasonic powers. In addition, ultrasonication treatment-induced changes in cell membrane integrity enhanced and/or disrupted permeability of L. delbrueckii, resulting in an imbalance in intracellular conditions associated with corresponding alterations in metabolic behaviors and fermentation efficiencies. UT-prestressed inoculum exhibited a 21.46% decrease in the membrane potential during the lag phase compared to untreated samples, with an intracellular pH of 5.68 ± 0.12, attributed to the lower activities of H+-ATPase and lactate dehydrogenase due to UT stress pretreatments. Comparative transcriptomic analysis revealed that UT prestress influenced the genes related to glycolysis, pyruvate metabolism, fatty acid synthesis, and ABC transport. The genes encoding 3-oxoacyl-[acyl-carrier-protein] reductases I, II, and III, CoA carboxylase, lactate dehydrogenase, pyruvate oxidase, glucose-6-phosphate isomerase, and glycerol-3-phosphate dehydrogenase were downregulated, thus identifying the relevance of the UT microstresses-downregulated absorption and utilization of carbohydrates with the attenuated fatty acid production and energy metabolisms. These findings could contribute to provide a better understanding of the inactivated effects on the post-acidification of L. delbrueckii by ultrasonic pretreatments, thus providing theoretical basis for the targeted optimization of acidification inhibition efficiencies for yogurt products during chilled preservation processes.


Assuntos
Fermentação , Perfilação da Expressão Gênica , Lactobacillus delbrueckii , Lactobacillus delbrueckii/metabolismo , Lactobacillus delbrueckii/genética , Concentração de Íons de Hidrogênio , Transcriptoma , Sonicação , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética
2.
Biomed Chromatogr ; 38(2): e5779, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38050189

RESUMO

To clarify the residue behavior and possible dietary risk of abamectin in fresh corn, bitter melon, and Fritillaria, a method was developed for the simultaneous determination of abamectin residues in fresh corn, bitter melon, and Fritillaria by QuEChERS (quick, easy, cheap, effective, rugged, safe) ultra-performance liquid chromatography-tandem mass spectrometry. The mean recovery of abamectin in fresh corn, bitter melon, and Fritillaria was 86.48%-107.80%, and the relative standard deviation was 2.07%-10.12%. The detection rates of abamectin residues in fresh corn, bitter melon, and Fritillaria were 62.50%, 87.50%, and 80.00%, respectively. The residues of abamectin in fresh corn, bitter melon, and Fritillaria were not more than 0.020, 0.019, and 0.087 mg/kg, respectively. Based on these results, dietary risk assessment showed that the risk content of abamectin residues in long- and short-term dietary exposure for Chinese consumers was 61.57% and 0.41%-1.11%, respectively, indicating that abamectin in fresh corn, bitter melon, and Fritillaria in the market would not pose a significant risk to consumers.


Assuntos
Fritillaria , Ivermectina/análogos & derivados , Momordica charantia , Resíduos de Praguicidas , Momordica charantia/química , Zea mays , Medição de Risco , Resíduos de Praguicidas/análise
3.
J Dairy Sci ; 107(5): 2760-2773, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38135047

RESUMO

This study aims to identify lactic acid bacteria (LAB) isolates possessing physiological characteristics suitable for use as probiotics in yogurt fermentation. Following acid and bile salt tolerance tests, Lactiplantibacillus plantarum (NUC08 and NUC101), Lacticaseibacillus rhamnosus (NUC55 and NUC201), and Lacticaseibacillus paracasei (NUC159, NUC216, and NUC351) were shortlisted based on intraspecies distribution for further evaluation. Their physiological probiotic properties, including transit tolerance, adhesion, autoaggregation, surface hydrophobicity, biofilm formation, and antibacterial activity, were assessed. Principal component analysis indicated that Lactiplantibacillus plantarum NUC08 was the preferred choice among the evaluated strains. Subsequent investigations revealed that co-culturing Lactiplantibacillus plantarum NUC08 with 2 yogurt starter strains resulted in a cooperative and synergistic effect, enhancing the growth of mixed strains and increasing their tolerance to simulated gastric and intestinal conditions. Additionally, when Vibrio harveyi bioluminescent reporter strain was used, the 3 cocultured strains cooperated to induce the activity of a quorum sensing (QS) molecule autoinducer-2 (AI-2), hinting a potential connection between phenotypic traits and QS in the cocultured strains. Importantly, LAB viable counts were significantly higher in yogurt co-fermented with Lactiplantibacillus plantarum NUC08, consistently throughout the storage period. In conclusion, the study demonstrates that the probiotic strain Lactiplantibacillus plantarum NUC08 can be employed in synergy with yogurt starter strains, affirming its potential for use in the development of functional fermented dairy products.


Assuntos
Produtos Fermentados do Leite , Lactobacillus plantarum , Probióticos , Animais , Iogurte/microbiologia , Lactobacillus plantarum/fisiologia , Lactobacillaceae
4.
Int J Mol Sci ; 24(7)2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37047555

RESUMO

Flavonoids are easily destroyed and their activity lost during gastrointestinal digestion. Protein-based nanocomplexes, a delivery system that promotes nutrient stability and bioactivity, have received increasing attention in recent years. This study investigated the stability, inhibitory activity against α-glucosidase and interaction mechanisms of protein-based nanocomplexes combining whey protein isolate (WPI), soybean protein isolate (SPI) and bovine serum albumin (BSA) with flavonoids (F) from A. keiskei using spectrophotometry, fluorescence spectra and molecular docking approaches. The results show that the flavonoid content of WPI-F (23.17 ± 0.86 mg/g) was higher than those of SPI-F (19.41 ± 0.56 mg/g) and BSA-F (20.15 ± 0.62 mg/g) after simulated digestion in vitro. Furthermore, the inhibition rate of WPI-F (23.63 ± 0.02%) against α-glucosidase was also better than those of SPI-F (18.56 ± 0.02%) and BSA-F (21.62 ± 0.02%). The inhibition rate of WPI-F increased to nearly double that of F alone (12.43 ± 0.02%) (p < 0.05). Molecular docking results indicated that the protein-flavonoids (P-F) binding occurs primarily through hydrophobic forces, hydrogen bonds and ionic bonds. Thermodynamic analysis (ΔH > 0, ΔS > 0) indicated that the P-F interactions are predominantly hydrophobic forces. In addition, the absolute value of ΔG for WPI-F is greater (-30.22 ± 2.69 kJ mol-1), indicating that WPI-F releases more heat energy when synthesized and is more conducive to combination. This paper serves as a valuable reference for the stability and bioactivity of flavonoids from A. keiskei.


Assuntos
Angelica , Flavonoides , Flavonoides/farmacologia , Flavonoides/química , alfa-Glucosidases/metabolismo , Simulação de Acoplamento Molecular , Angelica/metabolismo , Ligação Proteica , Termodinâmica , Soroalbumina Bovina/química , Espectrometria de Fluorescência
5.
J Sci Food Agric ; 103(8): 3915-3925, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36335574

RESUMO

BACKGROUND: The traditional screening method for umami peptide, extracted from porcine bone, was labor-intensive and time-consuming. In this study, the rapid screening method and molecular mechanism of umami peptide was investigated. RESULTS: This article showed that a more precisely rapid screening method with composite machine learning and molecular docking was used to screen the potential umami peptide from porcine bone. As reference, 24 reported umami peptides were predicated by composite machine learning, with the accuracy of 86.7%. In this study, potential umami peptide sequences from porcine bone were screened by UMPred-FRL, Umami-MRNN Demo, and molecular docking was used to provide further screening. Finally, nine peptides were screened and verified as umami peptides by this method: LREY, HEAL, LAKVH, FQKVVA, HVKELE, AEVKKAP, EAVEKPQS, KALSEEL and KKMFETES. The hydrogen bonding was deemed to be the main interaction force with receptor T1R3, and domain binding sites were Ser146, His121 and Glu277. The result demonstrated the feasibility of machine learning assisted T1R1/T1R3 receptor for rapid screening umami peptides. The screening method would not only adapt to screen umami peptides from porcine bone but possibly applied for other sources. It also provided a reference for rapid screening of umami peptides. CONCLUSION: The manuscript lays a rapid screening method in screening umami peptide, and nine umami peptides from porcine bone were screened and identified. © 2022 Society of Chemical Industry.


Assuntos
Peptídeos , Receptores Acoplados a Proteínas G , Suínos , Simulação de Acoplamento Molecular , Receptores Acoplados a Proteínas G/metabolismo , Peptídeos/química , Sítios de Ligação , Ligação de Hidrogênio , Paladar , Animais
6.
Appl Microbiol Biotechnol ; 106(7): 2481-2491, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35344091

RESUMO

Herein, two genes (LBA0625 and LBA1719) encoding UGPases (UDP-glucose pyrophosphorylase) in Lactobacillus acidophilus (L. acidophilus) were successfully transformed into Escherichia coli BL21 (DE3) to construct recombinant overexpressing strains (E-0625, E-1719) to investigate the biological characteristics of UGPase-0625 and UGPase-1719. The active sites, polysaccharide yield, and anti-freeze-drying stress of L. acidophilus ATCC4356 were also detected. UGPase-0625 and UGPase-1719 belong to the nucleotidyltransferase of stable hydrophilic proteins; contain 300 and 294 amino acids, respectively; and have 20 conserved active sites by prediction. Αlpha-helixes and random coils were the main secondary structures, which constituted the main skeleton of UGPases. The optimal mixture for the high catalytic activity of the two UGPases included 0.5 mM UDP-Glu (uridine diphosphate glucose) and Mg2+ at 37 °C, pH 10.0. By comparing the UGPase activities of the mutant strains with the original recombinant strains, A10, L130, and L263 were determined as the active sites of UGPase-0625 (P < 0.01) and A11, L130, and L263 were determined as the active sites of UGPase-1719 (P < 0.01). In addition, UGPase overexpression could increase the production of polysaccharides and the survival rates of recombinant bacteria after freeze-drying. This is the first study to determine the enzymatic properties, active sites, and structural simulation of UGPases from L. acidophilus, providing in-depth understanding of the biological characteristics of UGPases in lactic acid bacteria.Key points• We detected the biological characteristics of UGPases encoded by LBA0625 and LBA1719.• We identified UGPase-0625 and UGPase-1719 active sites.• UGPase overexpression elevates polysaccharide levels and post-freeze-drying survival.


Assuntos
Lactobacillus acidophilus , UTP-Glucose-1-Fosfato Uridililtransferase , Domínio Catalítico , Lactobacillus acidophilus/genética , Lactobacillus acidophilus/metabolismo , Estrutura Secundária de Proteína , UTP-Glucose-1-Fosfato Uridililtransferase/química , UTP-Glucose-1-Fosfato Uridililtransferase/genética , UTP-Glucose-1-Fosfato Uridililtransferase/metabolismo , Uridina Difosfato Glucose/metabolismo
7.
Mikrochim Acta ; 189(11): 433, 2022 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-36287256

RESUMO

A rapid, convenient, low-cost, and selective DNA isolation method was developed for identifying meat adulteration. A mesoporous metal organic framework (Meso-UIO-66)-coated solid phase microextraction system was employed as an isolation device to simplify DNA isolation into three steps (lysis, washing, and elution). Meso-UIO-66 was utilized as the adsorbent because of its positively charged surface, high chemical stability, and mesoporous structure. Meso-UIO-66 was characterized by scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet‒visible spectroscopy, X-ray photoelectron spectroscopy, and nitrogen adsorption-desorption tests. Parameters that affected DNA isolation were optimized. This method can be used to isolate and purify DNA from meat in 60 s, and the DNA concentration and purity are comparable to those of samples isolated with a commercial kit. Multiple DNA detection was achieved by coupling this method with the multiplex polymerase chain reaction technique, and the detection limit was lower than 1% (w/w).


Assuntos
Estruturas Metalorgânicas , Estruturas Metalorgânicas/química , Microextração em Fase Sólida/métodos , Pós , Limite de Detecção , Carne , Reação em Cadeia da Polimerase , DNA/genética , Nitrogênio
8.
Compr Rev Food Sci Food Saf ; 21(2): 1462-1490, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35201672

RESUMO

Umami is an important element affecting food taste, and the development of umami peptides is a topic of interest in food-flavoring research. The existing technology used for traditional screening of umami peptides is time-consuming and labor-intensive, making it difficult to meet the requirements of high-throughput screening, which limits the rapid development of umami peptides. The difficulty in performing a standard measurement of umami intensity is another problem that restricts the development of umami peptides. The existing methods are not sensitive and specific, making it difficult to achieve a standard evaluation of umami taste. This review summarizes the umami receptors and umami peptides, focusing on the problems restricting the development of umami peptides, high-throughput screening, and establishment of evaluation standards. The rapid screening of umami peptides was realized based on molecular docking technology and a machine learning method, and the standard evaluation of umami could be realized with a bionic taste sensor. The progress of rapid screening and evaluation methods significantly promotes the study of umami peptides and increases its application in the seasoning industry.


Assuntos
Peptídeos , Paladar , Simulação de Acoplamento Molecular , Peptídeos/química
9.
J Proteome Res ; 20(5): 2447-2457, 2021 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-33705137

RESUMO

The ability to survive in the harsh gastrointestinal tract (GIT) environment is essential for Lactobacillus reuteri (L. reuteri) exhibiting beneficial effects. In this study, we found that the hydrophobicity and auto-aggregation of L. reuteri SH23 were significantly decreased and biofilm production was also significantly decreased when L. reuteri SH23 passes through the simulated GIT. Furthermore, according to the comparative transcriptome analysis, gene expression involved in the cell envelope, metabolic processes, common stress response, regulatory systems, and transporters were also affected. Meanwhile, label-free quantitative proteomics was used to identify the differential expression of surface proteins of L. reuteri in response to simulated gastrointestinal fluid. Proteins related to the ABC transporters (Lreu_0517, Lreu_0098, and Lreu_0296) and LPxTG anchor domain proteins were upregulated in the cell surface after gastrointestinal fluid treatment, which is useful for adherence and colonization of L. reuteri in the GIT. Additionally, the recombinant Mub protein could also enhance the survival ability of L. reuteri SH23 in GIT stress environment. This study provides a comprehensive understanding of the adaptation and adhesion mechanisms of L. reuteri SH23 under the gastrointestinal tract by the transcriptomics and proteomics analysis, and mucus-binding proteins were involved in the adhesion and GIT tolerance process.


Assuntos
Limosilactobacillus reuteri , Probióticos , Aderência Bacteriana , Limosilactobacillus reuteri/genética , Muco , Proteômica , Transcriptoma
10.
Biotechnol Lett ; 43(4): 855-864, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33387114

RESUMO

OBJECT: As a broad-spectrum fluoroquinolone antibiotic drug, ciprofloxacin (CIP) is frequently used in the treatment of a wide variety of infections. However, the residues of this antibiotic pose a big threat to the aquatic environment and human health. In this research, Lactobacillus reuteri WQ-Y1 with CIP degradation ability was screened and identified. RESULTS: L. reuteri WQ-Y1 with a degradation rate of 65.1% for 4 µg mL-1 CIP was screened from 17 lactic acid bacteria (LAB), and cytochrome P450 enzyme was confirmed to promote the degradation of CIP by L. reuteri WQ-Y1. Meanwhile, the CIP degradation rate were also higher in 48 h' culture time when co-cultured with 1 mg/mL of glucose in the culture media. Furthermore, result also proved that fluoroquinolone antibiotics with the similar piperazine ring structures could be degraded by L. reuteri WQ-Y1. CONCLUSIONS: L. reuteri WQ-Y1 could degrade fluoroquinolone antibiotics with the similar piperazine ring structure. However, future work still needs to be done on the confirmation of the key enzymes in the cytochrome P450 enzymes family in the biodegradation. The isolated ciprofloxacin-degrading strain L. reuteri WQ-Y1 had a CIP degradation rate of 65.1% at 24 hours, and one biodegradation metabolite was identified and proved to be an important metabolite of CIP from cytochrome P450 enzymes family hydrolysis with UPLC-MS/MS spectrograms approach.


Assuntos
Ciprofloxacina/química , Glucose/química , Limosilactobacillus reuteri/crescimento & desenvolvimento , Técnicas Bacteriológicas , Biodegradação Ambiental , Cromatografia Líquida de Alta Pressão , Meios de Cultura/química , Sistema Enzimático do Citocromo P-450/metabolismo , Fermentação , Limosilactobacillus reuteri/isolamento & purificação , Limosilactobacillus reuteri/metabolismo , Espectrometria de Massas em Tandem
11.
Cell Microbiol ; 20(10): e12864, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29845725

RESUMO

Copper (Cu) and zinc (Zn) are essential nutrients for both pathogens and hosts; however, their excess accumulation is toxic for all cells. The Aspergillus transcription factor AceA has been identified having function for Cu detoxification through up-regulation of the expression of the P-type ATPase, CrpA. Here, we demonstrate that Aspergillus fumigatus CrpA is involved in both Cu and Zn detoxification and a putative metallothionein AfCrdA plays a major function in Cu detoxification, and a putative transporter AfZrcA has a dominant role in Zn detoxification, but all three members are transcriptionally dependent on AfAceA. Moreover, the Cys, RGHR, and KGRP motifs in the conserved N-terminus of AfAceA are essential, but not sufficient for AfAceA-mediated Cu and Zn tolerance. Our findings suggest that fungal pathogens have developed very precise systems with overlapping machinery to respond to the two different metal stressors. Meanwhile, there is separate specific machinery for Zn detoxification in response to high environmental Zn. Importantly, virulence testing demonstrated that the conserved Cu and Zn detoxification-related Cys residues in AfAceA have key roles in pathogenesis. Therefore, these findings will broaden the current understanding of the adaption of saprophytic fungi to Cu and Zn stress and their survival in hosts and other environmental niches.


Assuntos
Aspergillus fumigatus/metabolismo , Aspergillus fumigatus/patogenicidade , Proteínas de Transporte de Cátions/metabolismo , Cobre/metabolismo , Fatores de Transcrição/metabolismo , Zinco/metabolismo , Aspergillus fumigatus/genética , Inativação Metabólica/genética , Metalotioneína/metabolismo
12.
Fungal Genet Biol ; 107: 31-43, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28803907

RESUMO

Copper (Cu) is an essential trace element and is regarded as an important virulence factor in fungal pathogens. Previous studies suggest that a putative Cu-sensing transcription factor Mac1 and the Cu transporter Ctr family play important roles during fungal development and virulence. However, how Cu importers of the Ctr family are involved in the Cu acquisition and what is the functional relationship between them have not been fully investigated yet. Here, we demonstrate that the yeast Mac1 homolog in the opportunistic human pathogen Aspergillus fumigatus is required during colony development under low Cu conditions. Transcriptional profiling combined with LacZ reporter analyses indicate that Cu transporters ctrA2 and ctrC are expressed in an Afmac1-dependent manner upon Cu starvation, and over-expression of ctrA2 or ctrC transporters almost completely rescue the Afmac1-deletion defects, suggesting a redundancy of both transporters in Afmac1-mediated Cu uptake. Genetic analysis showed that ctrC may play a dominant role against Cu starvation relative to ctrA2 and elevated expression of ctrA2 can compensate for ctrC deletion under Cu starvation. Interestingly, both ctrA2 and ctrC deletions can suppress ctrB deletion colony defects. Our findings suggest that Ctr family proteins might coordinately regulate their functions to adapt to different Cu environments. Compared to yeast homologs, Cu family proteins in A. fumigatus may have their own working styles. Most importantly, the Afmac1 deletion strain shows a significantly attenuated pathogenicity in the neutropenic immunocompromised (a combination of cyclophosphamide and hydrocortisone) mice model, demonstrating that Afmac1 is required for pathogenesis in vivo.


Assuntos
Aspergillus fumigatus/metabolismo , Aspergillus fumigatus/patogenicidade , Cobre/metabolismo , Regulação Fúngica da Expressão Gênica , Proteínas de Membrana Transportadoras/genética , Fatores de Transcrição/genética , Aspergillus fumigatus/genética , Aspergillus fumigatus/crescimento & desenvolvimento , Proteínas Fúngicas/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Transcrição Gênica , Virulência , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
14.
Cancer Cell Int ; 16: 73, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27688736

RESUMO

BACKGROUND: Osteosarcoma is the most common malignancy of bone. Intratumoral hypoxia occurs in many solid tumors, where it is associated with the development of aggressive phenotype. ANRIL has been shown to be a long noncoding RNA that facilitates the progression of a number of malignancies. Yet, few studies have explored the expression pattern of ANRIL in osteosarcoma and the effect of hypoxia on ANRIL. METHODS: We evaluated the expression levels of ANRIL in osteosarcoma tissues, adjacent normal tissues and cells with quantitative real-time polymerase chain reaction. Multiple approaches including luciferase reporter assay with nucleotide substitutions, chromatin immunoprecipitation assay and electrophoretic mobility shift assay were used to confirm the direct binding of HIF-1α to the ANRIL promoter region. SiRNA-based knockdown and other molecular biology techniques were employed to measure the effect of HIF-1α on the expression of ANRIL. RESULTS: We found that the expression of ANRIL was upregulated in 15 pairs of osteosarcoma compared with adjacent normal tissues. We found that hypoxia is sufficient to upregulate ANRIL expression in osteosarcoma cells (MNNG and U2OS). HIF-1α directly binds to the putative hypoxia response element in the upstream region of ANRIL. What's more, siRNA and small molecular inhibitors-mediated HIF-1α suppression attenuated ANRIL upregulation under hypoxic conditions. Upon hypoxia, ANRIL promoted cancer cell invasion and suppressed cell apoptosis. CONCLUSION: Taken together, these data suggest that HIF-1α may contribute to the upregulation of ANRIL in osteosarcoma under hypoxic conditions. ANRIL is involved in hypoxia-induced aggressive phenotype in osteosarcoma.

15.
Fungal Genet Biol ; 81: 120-31, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25892048

RESUMO

CpcB (cross pathway control B) encodes a yeast Cpc2 and mammalian RACK1 (receptor for activated protein kinase C) ortholog, which is a WD repeat protein with functional homology to the ß subunit of heterotrimeric G proteins in Aspergillus fumigatus. Previous study has reported that CpcB governs growth and development in both A. fumigatus and Aspergillus nidulans. However, little is known about the functional identities of CpcB orthologs and their relationships with G protein complexes. In this study, we verified that cytoplasmic AfCpcB acts as a Gß-like protein ortholog and plays important roles in hyphal growth, conidiophore morphology, cell wall integrity, and virulence in A. fumigatus. Furthermore, double deletion of AfcpcB and AfgpaB (Gα) causes a similar phenotype to AfgpaB mutant with abnormal multiple septa conidiophores but exhibits sparse conidiation with white and fluffy colonies. Thus, the exacerbated conidiation defect suggests that AfcpcB has its own specific function compared to the Gα subunit of AfgpaB or the G-protein complex. In addition, complementation assays using AfcpcB orthologs of A. nidulans and yeasts (Saccharomyces cerevisiae, Schizosaccharomyces pombe, Candida albicans) suggest that all tested fungal AfcpcB orthologs under the A. fumigatus native promoter can largely restore hyphal growth defects in AfcpcB deletion mutant, but only the A. nidulans cpcB ortholog completely rescues the ΔAfcpcB conidiation defect, suggesting that CpcB acts as a Gß-like protein ortholog in the Aspergilli, but may have unique and important unexplored functions that required for conidiation, which is absent in yeast.


Assuntos
Aspergillus fumigatus/crescimento & desenvolvimento , Aspergillus fumigatus/patogenicidade , Proteínas de Ligação ao GTP/metabolismo , Regulação Fúngica da Expressão Gênica , Hifas/crescimento & desenvolvimento , Esporos Fúngicos/crescimento & desenvolvimento , Aspergillus fumigatus/genética , Deleção de Genes , Teste de Complementação Genética
16.
Fungal Genet Biol ; 81: 250-60, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25776795

RESUMO

Aspergillus fumigatus (A. fumigatus) commonly produces abundant and heavily melanized infectious conidia, which are the primary agents that cause invasive aspergillosis (IA) in immunocompromised patients. We isolated a white nonsporulating A. fumigatus strain (A1j) from an immunocompetent patient. It was identified by histopathological examination and morphological observation, and subsequently confirmed by DNA sequencing of internal transcribed spacer (ITS) regions and partial ß-tubulin genes. Neither a long waiting time nor passage on various medium types could stimulate the formation of spores and pigment. No significant relative difference was found in sensitivity to antifungal agents or cell wall destabilizing reagents, as compared to wild-type A. fumigatus Af293. Nevertheless, A1j was hypovirulent in the immunosuppressed mice model, consistent with the good result in our patient. RNA deep-sequencing analysis (RNA-seq) revealed that hundreds of transcripts were significantly dysregulated, including those related to pigmentation and sporulation. qRT-PCR confirmed the anergic state of key regulator brlA for sporulation under the induction of conidiation conditions, but without mutation. To the best of our knowledge, this is the first report of a white, nonsporulating A. fumigatus strain infection in an immunocompetent patient. In our opinion, A1j may represent a mutant of typical A. fumigatus, providing a new clue for identification of clinical A. fumigatus isolates. Furthermore, the good prognosis of our patient and the reduced virulence in the mice model infected with A1j highlight the potential of sporulation inhibitors as a new generation of antifungal agents.


Assuntos
Aspergilose/microbiologia , Aspergilose/patologia , Aspergillus fumigatus/crescimento & desenvolvimento , Mutação , Pigmentos Biológicos/metabolismo , Esporos Fúngicos/crescimento & desenvolvimento , Animais , Aspergillus fumigatus/genética , Aspergillus fumigatus/isolamento & purificação , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Camundongos , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de DNA , Tubulina (Proteína)/genética , Virulência
17.
Foods ; 13(2)2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38254570

RESUMO

To better understand the textural transformation of Chinese dried noodles during the drying process, a convenient acoustic-force detection method was established. By comparing the breaking point, it was possible to determine the time-scale correlation between the force-displacement curves and acoustic spectrograms. The acoustic eigenvalues showed a consistent upward trend with the mechanical parameters during the drying process. With a wave crest reaching 152.8 dB and a signal maximum reaching 0.072, the structural stability of the dried noodles hardly induces a higher acoustic response. This suggests that the mechanical strength and rigidity of the dried noodles undergo minimal changes during this period. In comparison to the mechanical parameters, the acoustic eigenvalues accurately describe the changes in texture of dried noodles under various drying conditions, moreover, the sound threshold also provides a more effective response to the dried noodles' structural strength threshold. Therefore, the acoustic detection method can be applied to assist the conventional mechanical measurement in the field of the texture evaluation of dried food.

18.
Ultrason Sonochem ; 105: 106857, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38552299

RESUMO

This work investigated the effects of the combined use of thermosonication-preconditioned lactic acid bacteria (LAB) with the addition of ultrasound-assisted pineapple peel extracts (UU group) on the post-acidification potential, physicochemical and functional qualities of yogurt products, aimed at achieving prolonged preservation and enhancing functional attributes. Accordingly, the physical-chemical features, adhesion properties, and sensory profiles, acidification kinetics, the contents of major organic acids, and antioxidant activities of the differentially processed yogurts during refrigeration were characterized. Following a 14-day chilled storage process, UU group exhibited acidity levels of 0.5-2 oT lower than the control group and a higher lactose content of 0.07 mg/ml as well as unmodified adhesion potential, indicating that the proposed combination method efficiently inhibited post-acidification and delayed lactose metabolism without leading to significant impairment of the probiotic properties. The results of physicochemical analysis showed no significant changes in viscosity, hardness, and color of yogurt. Furthermore, the total phenolic content of UU-treated samples was 98 µg/mL, 1.78 times higher than that of the control, corresponding with the significantly lower IC50 values of DPPH and ABTS radical scavenging activities of the UU group than those of the control group. Observations by fluorescence inverted microscopy demonstrated the obvious adhesion phenomenon with no significant difference found among differentially prepared yogurts. The results of targeted metabolomics indicated the proposed combination strategy significantly modified the microbial metabolism, leading to the delayed utilization of lactose and the inhibited conversion into glucose during post-fermentation, as well as the decreased lactic acid production and a notable shift towards the formation of relatively weak acids such as succinic acid and citric acid. This study confirmed the feasibility of thermosonication-preconditioned LAB inocula, in combination with the use of natural active components from fruit processing byproducts, to alleviate post-acidification in yogurt and to enhance its antioxidant activities as well as simultaneously maintaining sensory features.


Assuntos
Ananas , Antioxidantes , Fermentação , Extratos Vegetais , Iogurte , Iogurte/microbiologia , Iogurte/análise , Ananas/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Antioxidantes/farmacologia , Sonicação , Temperatura , Concentração de Íons de Hidrogênio , Manipulação de Alimentos/métodos , Qualidade dos Alimentos
19.
Front Psychol ; 13: 881491, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35496234

RESUMO

This study attempted to explore the personality traits of higher achievers at the university level. The core objective of this investigation was to illustrate the nature of personality traits of the higher achievers' students. To study this phenomenon, a quantitative research approach was used. The students were chosen by using a purposive sampling technique and included 758 high achievers enrolled in various programs at the Chinese universities. Based on the Hexaco model of personality, a questionnaire was used to gather information from respondents as a research tool to examine the personality traits of position holders after an extensive review of the relevant literature. Tool validity was determined by following the face, content, construct (convergent and discriminant validity) validation process. This investigation concluded that honesty, emotionality, and openness to experience were very high among the higher achievers' students. Only honesty in female higher achievers' students was significantly high than male, remaining factors "extraversion, agreeableness, conscientiousness, and openness to experience" were significantly high among male higher achievers' students. Moreover, the higher achievers of science group students were more extraversion, agreeableness, and conscientiousness than arts group students. However, higher achievers in hostels were more emotional and agreeableness than the day scholars. Overall step-wise regression analysis, indicated that agreeableness and extraversion factor has significant influence on higher achievers.

20.
Foods ; 11(11)2022 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-35681360

RESUMO

Lactobacillus are normal inhabitants of the gastrointestinal tract and confer a variety of health effects. Lipoteichoic acid (LTA), an amphiphilic substance located in the cell membrane, is a key molecule in probiotic-host crosstalk. Through the characterization of structural characteristics of LTA molecules derived from Lactobacillus plantarum A3, Lactobacillus reuteri DMSZ 8533, and Lactobacillus acidophilus CICC 6074, there exists some heterogeneity in LTA molecules, which perhaps contributes to the distinguishable adhesion properties of Lactobacillus strains based on fluorescence microscopy observations. In LPS-induced RAW 264.7 cells, LTAs derived from three Lactobacillus strains obviously alleviated inflammatory responses as evidenced by the altered inflammatory cytokine levels of TNF-α, IL-6, and IL-10. Western blotting demonstrated that L. reuteri LTA blocked LPS-triggered expression of the MAPK and NF-κB pathways. The findings further validated that LTA is an important effector molecule and deserves further consideration as an alternative therapeutic for ulcerative colitis treatment.

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