Novel Lipase from Golden Pompano(Trachinotus ovatus)Viscera:Purification,Characterization,and Application in the Concentrating of n-3 Polyunsaturated Fatty Acids

Lipases have been widely applied in a variety of industrial fields,such as food,pharmaceuticals,biofuels,and biotechnology.Recent years have witnessed a great interest in modifying lipids for the production of triacylglycerols enriched with n-3 polyunsaturated fatty acids(PUFAs).Here,a novel salt-tolerant,organic solvent-stable,and bile salt-activated lipase was purified from golden pompano(Trachinotus ovatus)viscera,which was named as golden pompano lipase(GPL).GPL had a specific activity of 57.2U mg^(-1)with an estimated molecular weight of 14 k Da,exhibited optimal activity at 40℃a nd pH 8.0,and showed K_(m)and V_(max)of 40.16μmol L^(-1)and 769.23μmol L^(-1)min^(-1),respectively.GPL activity was enhanced by Mn^(2+)and sodium deoxycholate.It was active in organic solvents,including methanol,ethanol,chloroform,and hexane.GPL also showed a good salinity tolerance of up to 1 mol L^(-1).n-3PUFA enrichment in the glyceride fraction of golden pompano oil was performed by GPL-catalyzed hydrolysis and yielded a total PUFA concentration of 56.99%.EPA,DHA,and DPA were enriched by 10.4-,3.2-,and 1.8-fold of their initial levels,respectively.This study recognized the industrial applicability of GPL to prepare enriched C_(20-22)n-3 PUFA.

Anti-diabetic potential of apigenin,luteolin,and baicalein via partially activating PI3K/Akt/GLUT-4 signaling pathways in insulin-resistant HepG2 cells

Dietary flavonoids are abundant in natural plants and possess multiple pharmacological and nutritional activities.In this study,apigenin,luteolin,and baicalein were chosen to evaluate their anti-diabetic effect in high-glucose and dexamethasone induced insulin-resistant(IR)HepG2 cells.All flavonoids improves the glucose consumption and glycogen synthesis abilities in IR-HepG2 cells via activating glucose transporter protein 4(GLUT4)and phosphor-glycogen synthase kinase(GSK-3β).These fl avonoids signifi cantly inhibited the production of reactive oxygen species(ROS)and advanced glycation end-products(AGEs),which were closely related to the suppression of the phosphorylation form of NF-κB and P65.The expression levels of insulin receptor substrate-1(IRS-1),insulin receptor substrate-2(IRS-2)and phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt)pathway in IR-HepG2 cells were all partially activated by the fl avonoids,with variable effects.Furthermore,the intracellular metabolic conditions of the fl avonoids were also evaluated.

Isolation and characterization of bioactive fungi from shark Carcharodon carcharias' gill with biopharmaceutical prospects

Until recently,little was known about the fungi found in shark gills and their biomedicinal potential. In this article,we described the isolation,bioactivity,diversity,and secondary metabolites of bioactive fungi from the gill of a shark(Carcharodon carcharias). A total of 115 isolates were obtained and grown in 12 culture media. Fifty-eight of these isolates demonstrated significant activity in four antimicrobial,pesticidal,and cytotoxic bioassay models. Four randomly selected bioactive isolates inhibited human cancer cell proliferation during re-screening. These active isolates were segregated into 6 genera using the internal transcribed spacer-large subunit(ITS-LSU) rDNA-sequence BLAST comparison. Four genera,Penicillium,Aspergillus,Mucor,and Chaetomium were the dominant taxa. A phylogenic tree illustrated their intergenera and intragenera genetic diversity. HPLC-DAD-HRMS analysis and subsequent database searching revealed that nine representative strains produced diverse bioactive compound profiles. These results detail the broad range of bioactive fungi found in a shark's gills,revealing their biopharmaceutical potential. To the best of our knowledge,this is the first study characterizing shark gill fungi and their bioactivity.

Nutritional properties of Europen eel(Anguilla anguilla)bone peptide-calcium and its apoptosis effect on Caco-2 cells

The present study aimed at making a rational usage for European eel bone by-products by preparing Europen eel bone peptide chelated calcium(EBPC-Ca).Nutritional properties and bioactivity of EBPC-Ca were evaluated.Results showed that nutritional properties of calcium ions will cause intra-and inter-molecular folding and aggregation of peptide to uniformly form EBPC-Ca chelate.The chelated compound of EBPC and calcium ion triggered a strong apoptosis in heterogeneous human epithelial colorectal adenocarcinoma(Caco-2)in concentration-and time-dependent manners.Western blot analysis revealed that the EBPC-Ca induced apoptosis may be the result of a blocked autophagy flux through mitochondrial-dependent pathway.Additionally,the increase in FGF-23 protein expression inhibited the absorption of calcium ions and alleviated cell apoptosis.It was also found that the cell apoptosis occurs with significant increases in the levels of reactive oxygen species(ROS)and Ca^(2+)in the cells,indicating the anti-tumor potential of EBPC-Ca may involve multiple channels.

Investigation of Export Aquaculture in Zhanjiang City and Development Suggestions

History of aquaculture in Zhanjiang City was reviewed by reviewing literatures, human resources, cultured species and culture modes, and distribution of aquaculture system were investigated and summarized. Output and export of processed aquatic products of Zhanjiang in the past years were analyzed, and the role of export aquaculture in economic development and social construction of Zhanjiang City was explored, and suggestions were given for enhancing the development of local export aquaculture.

Oyster Protein Hydrolysate Alleviates Cadmium Toxicity by Restoring Cadmium-Induced Intestinal Damage and Gut Microbiota Dysbiosis in Mice via Its Abundance of Methionine,Tyrosine,and Glutamine

As a typical heavy metal contaminant in food,cadmium(Cd)easily enters the human food chain via crop production,and therefore,threatens human health[1].Intestinal absorption is the principal route for Cd entry into the body,and therefore,intestinal tissue become the primary target for Cd toxicity[2].Previous studies showed that acute Cd exposure damaged intestinal tight junctions,resulting in gut barrier destruction and alterations in gut microbiota[3].Thus,the effective prevention of Cd-induced intestinal damage has become a major research challenge.

The role of flavonoids in mitigating food originated heterocyclic aromatic amines that concerns human wellness

Meat products are an important part in our daily diet,providing valuable nutrients for the human body.However,heating processes cause the meat to become more appetizing with changes in texture,appearance,flavor,and chemical properties by the altering of protein structure and other ingredients.As one kind of cooking-induced contaminants,heterocyclic aromatic amines(HAAs)are widely present in protein aceous food products with strong carcinogenic and mutagenic properties.In order to promote the safety of traditional meat products,this review focused on the formation,metabolism,biological monitoring and inhibitory mechanism of HAA.An overview of the formation pathways,hazards,and control methods of HAAs during food processing in recent years was studied,aiming to provide some valuable information for exploring effective methods to inhibit the production of associated hazards during food processing.Systematic selection of different types of flavonoids to explore their effects on the formation of HAAs in an actual barbecue system can provide theoretical reference for effectively controlling the formation of HAAs and reducing their harm to human health.

Endogenous Trypsin Triggers Free Fluoride Release from Antarctic Krill(Euphausia superba)Cuticle

During postmortem storage,fluoride in Antarctic krill can be enriched in the muscle.Trypsin,as the most important digestive enzyme in Antarctic krill with a high activity in low temperature,plays a potential role in this process.In this study,endogenous trypsin was purified and its properties were investigated.The involvement of trypsin in the generation of free fluoride from Antarctic krill cuticle was explored.Cuticle microstructure before and after hydrolysis was compared with scanning electron microscopy,and the ash samples of the hydrolyzed Antarctic krill cuticle were analyzed with X-ray diffraction,Fourier transform infrared spectroscopy,and electron dispersive spectroscopy,respectively.Mass spectrometry analysis and inhibition tests confirmed that the purified enzyme was endogenous trypsin.Results of the present study indicated that trypsin digestion caused the increases of the concentrations of both fluoride ions and free amino N simultaneously,while the protein coated on the cuticle surface was dissolved too.However,no compositional change was detected in the cuticle inorganic salts.These findings suggest that trypsin triggered free fluoride release from Antarctic krill cuticle.In addition,the kinetics of free fluoride release could be described by the equation C_(W)=(1-0.97^(-0.006t)-0.03e^(0.0558t))x337.53+10.50.The present study improved the understanding of the role of trypsin in free fluoride release from Antarctic krill cuticle,facilitating future studies aimed at reducing the fluoride content in krill protein during Antarctic krill processing.

富油新绿藻在不同培养期油脂的脂肪酸组成

用改良SE培养基培养富油新绿藻(Neochloris oleoabundans),用缺氮改良SE培养基培养处于稳定期后期的藻细胞3 d,分别收集处于生长期、稳定期、衰亡期和缺氮胁迫状态的藻细胞,用Folch法提取藻细胞油脂,以质量法计算油脂产率,用气相色谱法测定脂肪酸组成。结果表明,富油新绿藻随着培养期延长油脂含量提高,在缺氮胁迫状态下藻细胞油脂质量分数达28.99%;随着细胞油脂含量的增加,油脂脂肪酸组成也发生变化,从生长期到氮缺乏胁迫状态油酸质量分数由24%增至44%,而亚油酸质量分数由26.84%降至19.85%,亚麻酸质量分数由12.74%降至4.75%。富油新绿藻在分批培养后期和氮缺乏而碳源充足的条件下可积累油脂,而在油脂积累阶段油脂的脂肪酸组成亦不同。

Physicochemical properties of gelatin produced from Nile tilapia skin using chemical and fermentation pretreatments

In this study,we aimed to verify the effectiveness of fermentation as a pretreatment in Nile tilapia(Oreochromis niloticus)skin gelatin production and to assess its effects on the extracted gelatin.Chemical-gelatin(CG)and fermentation-gelatin(FG)were extracted using hot water from tilapia skin after immersion in chemical reagents(sodium hydroxide and butanol)and after fermentation with Bacillus velezensis FEL-BM21,respectively.FG presented a higher recovery(27.40%),yield(49.99%),and imino acid(proline and hydroxyproline)content(177.17±0.35 residues/1000 residues)than CG,but had a lower molecular weight.Fourier transform infrared and circular dichroism spectroscopy confirmed that the collagen was denatured,and scanning electron microscopy revealed that FG had a more continuous filamentous structure than CG.Furthermore,except for transmittance(66.19%at 450 nm and 86.36%at 620 nm),FG exhibited higher gel strength(492.81 g),gelling point(28.93℃),and melting point(18.33℃)than CG.These findings suggest that fermentation can be used to treat gelatin raw materials without negatively affecting the structure of gelatin.Moreover,fermentation has potential industrial applications as an alternative to chemical treatment.

Effects of Rhodiola rosea and its major compounds on insulin resistance in Caenorhabditis elegans

By establishing insulin resistance model of Caenorhabditis elegans,the effects of Rhodiola rosea extract and its compounds on glucose level,insulin signal intensity,antioxidant enzymes and cell apoptosis of C.elegans were investigated in present study.The mRNA expression of DAF-2,DAF-16,AkT-1,SKN-1,AAK-2 and SOD-3 were detected by qRT-PCR.The results revealed that R.rosea extract contain salidroside,kaempferol,chlorogenic acid,kaemphenol-7-O-glucoside,caffeic acid,and quercetin,etc.At the concentration of 200μg/mL,R.rosea extract treated C.elegans showed increased insulin signal intensity by 52.46%compared with the normal group,while,glucose content decreased by 72.13%and reactive oxygen species(ROS)level decreased by 36.84%.Compared with high glucose model group,the activities of superoxide dismutase(SOD),catalase(CAT)and glutathione peroxidase(GSH-Px)increased by 10.9,14.2 and 27.9,respectively.After R.rosea extract intervention,the expression levels of DAF-2,AkT-1,AAK-2,SKN-1 and other genes significantly increased.These results also indicated that R.rosea extract could activate insulin receptor substrate(IRS)and adenosine 5′-monophosphate(AMP)-activated protein kinase(AMPK)pathways to enhance insulin signaling,promote nutrient metabolism,and achieve the effect for improving insulin resistance of C.elegans.