查看更多>>摘要：Bioremediation of organophosphorus pesticides in contaminated foodstuffs using probiotics has been increasingly under the spotlight in recent years,though the biodegradation mechanism and derived intermediate products remain unclear.This study aimed to help fill this knowledge gap and examined the degradation mechanism of organophosphorus pesticide,chlorpyrifos,in milk by Lactobacillus delbrueckii ssp.bulgaricus using gas chromatography-tandem mass spectrometry(GC-MS/MS)combined with transcriptome analysis.After the strain was cultured for 20 h in the presence of chlorpyrifos,differential expressions of 383 genes were detected,including genes probably implicated during chlorpyrifos degradation such as those related to hydrolase,phosphoesterase,diphosphatase,oxidoreductase,dehydratase,as well as membrane transporters.GC-MS/MS analysis revealed the changes of secondary metabolites in L.bulgaricus during milk fermentation due to chlorpyrifos stress.6-Methylhexahydro-2H-azepin-2-one,2,6-dihydroxypyridine and methyl 2-aminooxy-4-methylpentanoate as intermediates,along with the proposed pathways,might be involved in chlorpyrifos biodegradation by L.bulgaricus.
查看更多>>摘要：Natural polysaccharides named PEP-0.1-1,PEP-0-1 and PEP-0-2 from edible mushroom species Pleurotus eryngii were obtained in the present study.Results showed that molecular weights of these polysaccharides were 3 235,2 041 and 23 933 Da,respectively.Further,structural characterization revealed that PEP-0.1-1 had a →4-α-D-Glcp-1→ backbone and contained →4)-α-D-Glcp and →4)-β-D-Glcp reducing end groups.PEP-0-1 backbone contained→4-α-D-Glcp-1→ and →6-α-3-O-Me-D-Galp-1→,and the side chains contained α-D-Glcp,β-D-Manp-1→ and α-D-Glcp-3→.However,PEP-0-2 backbone consisted of →4-α-D-Glcp-1→ and →6-α-3-O-Me-D-Galp-(1→6)-α-D-Galp-1→ while the side chains contained α-D-Glcp and β-D-Manp-1→.Biological activity analysis was then carried out and found that all these polysaccharides could significantly suppress the relative mRNA expression of toll-like receptor 4,nitric oxide(NO),tumor necrosis factor-α,interleukin(IL)-1β and IL-6 in lipopolysaccharide(LPS)-induced inflammation of RAW264.7 cells,as well as the over secretion of the above cell cytokines.Moreover,Western blotting analysis revealed that all these purified fractions displayed significant inhibition effects on the expression of c-Jun N-terminal kinases protein induced by LPS in mitogen activated protein kinase pathway,along with the relieving on the inhibition effect of LPS on IκB-α protein expression.In summary,the information generated by the present study could provide a theoretical basis for the exploration of novel healthy food materials from edible mushroom with anti-inflammation activities.
查看更多>>摘要：Previous research reported litchi thaumatin-like protein(LcTLP)could lead to inflammation,which is a factor causing the adverse reactions after excessive intake of litchi.As a main amino acid in litchi pulp,γ-aminobutyric acid(GABA)was found with anti-inflammatory effect.Therefore,this study aimed to investigate the effects of GABA on LcTLP-induced inflammation through RAW264.7 macrophages and C57BL mice models.In vitro study showed GABA could effectively regulate the level of inflammatory cytokines(interleukin(IL)-1β,IL-6,IL-10,and prostaglandin E2)and Ca2+in cells,and inhibit the phosphorylation of p65,IκB,p38,c-Jun N-terminal kinase(JNK)and extracellular signal-regulated kinase(ERK).These results indicate GABA alleviated inflammation through nuclear factor-κB and mitogen-activated protein kinase pathway signaling pathways.In vivo experiment was performed to verify the anti-inflammatory effect of GABA,and the results demonstrated that GABA reduced the inflammation and oxidative stress in the liver of LcTLP-treated mice,as it down-regulated the pro-inflammatory cytokines,malondialdehyde,aspartate transferase,and alanine transaminase.The relative expression of phosphorylated p38,JNK and ERK in mice liver with GABA treatment were reduced to 65%,39%and 80%of the control group,respectively.Furthermore,GABA treatment enriched probiotic bacteria and decreased pathogenic bacteria in mice gut,which reveals GABA could effectively reduce the translocation of gut microbiota.
查看更多>>摘要：This study investigated if the variation in the effect of anti-cholesterol(AC)treatment on individual mice are related to gut microbiome composition.The bile salt hydrolase(BSH)activity of 23 commercial fermented milk products was examined to select a fermented milk product for AC treatment.Mice were fed to different diets for 6 weeks:high-fat(60%of total calories from fat;D1),high-dietary fibre(20%cellulose;D2),and low-fat(17.2%of total calories from fat;D3)diets to change their gut microbiomes.Subsequently,faecal microbiome was transplanted(FMT)into mice treated with high cholesterol diet contained 2%cholesterol,followed by AC or non-AC(sterile tap water,STW)treatments.Control groups with normal(NC)and high-cholesterol diets(PC)were prepared for both AC and STW treatment.All experimental groups were subjected to serum and liver cholesterol,cholesterol metabolism-related(CMR)gene expression,and intestinal microbiome analyses.D3-FMT mice showed the most significant enhancements in cholesterol ratio and decreased hepatic cholesterol levels with AC treatment.Moreover,upregulation of the Cyp7a1 gene expression was observed in this group.Furthermore,the intestinal microbiome analysis indicated higher abundances of BSH-producing Eubacterium,Bifidobacterium,and Parabacteroides in the D3-FMT+AC group compare to others,potentially contributing to increased bile acid synthesis.
查看更多>>摘要：The wild Lepista sordida is a kind of precious and rare edible fungus.An excellent strain of it by artificial domestication was obtained,which was high-yield and high in iron content.In this study,high-throughput comparative proteomics was used to reveal the regulatory mechanism of its primordium differentiation in the early fruiting body formation.The mycelium before the primordium differentiation mainly expressed high levels of mitochondrial functional proteins and carbon dioxide concentration regulatory proteins.In young mushrooms,the highly expressed proteins were mainly involved in cell component generation,cell proliferation,nitrogen compound metabolism,nucleotide metabolism,glutathione metabolism,and purine metabolism.The differential regulation patterns of pileus and stipe growth to maturity were also revealed.The highly expressed proteins related to transcription,RNA splicing,the production of various organelles,DNA conformational change,nucleosome organization,protein processing,maturation and transport,and cell detoxification regulated the pileus development and maturity.The proteins related to carbohydrate and energy metabolism,large amounts of obsolete cytoplasmic parts,nutrient deprivation,and external stimuli regulated the stipe development and maturity.Multiple CAZymes regulated nutrient absorption,morphogenesis,spore production,stress response,and other life activities at different growth and development stages.
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