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1.
Sci Total Environ ; 934: 173118, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38750757

RESUMEN

The brominated flame retardant 2,2',4,4'-tetrabromodiphenyl ether (PBDE-47) is a ubiquitous environmental pollutant that causes neurotoxicity. However, incomplete understanding of the underlying mechanisms has hampered the development of effective intervention strategies. Oxidative stress and related cell death are the modes of action for PBDE-47 neurotoxicity, which are also the characteristics of ferroptosis. Nonetheless, the role of ferroptosis in PBDE-47-induced neurotoxicity remains unclear. In the present study, we found that PBDE-47 triggered ferroptosis in neuron-like PC12 cells, as evidenced by intracellular iron overload, lipid peroxidation, and mitochondrial damage. This was confirmed by ferroptosis inhibitors including the lipid reactive oxygen species scavenger ferrostatin-1 and iron chelator deferoxamine mesylate. Mechanistically, PBDE-47 impaired ferritinophagy by disrupting nuclear receptor coactivator 4-mediated lysosomal degradation of the iron storage protein ferritin. Moreover, PBDE-47 disturbed iron metabolism by increasing cellular iron import via upregulation of transferrin receptor 1 and decreasing cellular iron export via downregulation of ferroportin 1 (FPN1). Intriguingly, rescuing lysosomal function by overexpressing cathepsin B (CatB) mitigated PBDE-47-induced ferroptosis by partially restoring dysfunctional ferritinophagy and enhancing iron excretion via the upregulation of FPN1. However, FPN1 knockdown reversed the beneficial effects of CatB overexpression on the PBDE-47-induced iron overload. Finally, network pharmacology integrated with experimental validation revealed that Canolol, the main phenolic compound in canola oil, protected against PBDE-47-evoked iron overload, resulting in ferroptosis by restoring defective ferritinophagy and improving abnormal iron metabolism via lowering iron uptake and facilitating iron excretion. Overall, these data suggest that ferroptosis is a novel mechanism of PBDE-47-induced neuronal death and that manipulation of ferritinophagy and iron metabolism via Canolol represents a promising therapeutic strategy.

2.
Food Res Int ; 175: 113673, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38129022

RESUMEN

Enrichment of plant proteins with functionality is of great importance for expanding their application in food formulations. This study proposed an innovation to co-enrich soy protein and flaxseed protein to act as efficient interfacial stabilizers for generating foams and emulsions. The structure, interfacial properties, and functionalities of the soy protein-flaxseed protein natural nanoparticles (SFNPs) obtained by alkali extraction-isoelectric precipitation (AE) and salt extraction-dialysis (SE) methods were investigated. Overall, the foamability of AE-SFNPs (194.67 %) was 1.45-fold that of SE-SFNPs, due to their more flexible structure, smaller particle size, and suitable surface wettability, promoting diffusion and adsorption at the air-water interface. AE-SFNPs showed higher emulsion stability (140.89 min), probably because the adsorbed AE-SFNPs with smaller size displayed soft particle-like properties and stronger interfacial flexibility, and therefore could densely and evenly arrange at the interface, facilitating the formation of a stiff and solid-like interfacial layer, beneficial for more stable emulsion formation. The findings may innovatively expand the applications of SFNPs as food ingredients.


Asunto(s)
Lino , Proteínas de Soja , Proteínas de Soja/química , Emulsiones/química , Diálisis Renal , Proteínas de Plantas/química
3.
Anal Chem ; 95(43): 15933-15942, 2023 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-37852209

RESUMEN

Accurate oxylipin annotation is crucial for advancing our understanding of physiological processes in health and disease and identifying biomarkers. However, a full view of oxylipins for early diagnosis needs further attention due to the lack of proper analytical methods, which may be attributed to the wide dynamic range, poor sensitivity, extreme molecular complexity, and limited commercially available standards of oxylipins. Here, we devised a novel method by combining a chemical derivatization (CD)-based retention index (RI) algorithm and feature tandem mass spectrometric fragmentation annotation (CD-RI-LC-MS/MS) for identification and quantification of oxylipins. To this end, N,N-diethyl-1,3-diaminopropane (DEPA) was used for fast labeling of oxylipin (within 0.5 min at room temperature) to improve separation resolution and detection sensitivity. The RI algorithm was established to calibrate the retention time variances and assist the identification of oxylipins during liquid chromatography-tandem mass spectrometry (LC-MS) analysis. MS/MS analysis of in total 58 DEPA derivatives of authentic oxylipin standards was subsequently employed to obtain the tandem mass spectrometric feature fragmentation rules for further structure elucidation of the unknown regio-isomers. Finally, a method based upon CD-RI-LC-MS/MS was established for profiling oxylipins from Standard Reference Material (SRM) 1950 human plasma and nonalcoholic fatty liver disease (NAFLD) mouse liver tissue samples. A total of 87 and 96 potential oxylipins including 12 and 14 unreported oxylipins were detected and identified from human plasma and mouse liver tissues, respectively. The results showed that compared to the control group, in the liver samples of the NAFLD mouse, the content levels of prostaglandin (PG) E2, PGF2a, 8-hydroxy-eicosatrienoic acid (8-HETrE), and the newly discovered 2-hydroxy-octadecatrienoic acid (2-HOTrE) were remarkably increased, while the oxidation product of n-3 PUFA (p < 0.05) and all hydroperoxy oxylipins significantly decreased. On balance, this method contributes to future studies on oxylipin screening and application in other biological samples for facilitating the understanding of oxylipin roles in metabolic regulation of numerous diseases.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Oxilipinas , Humanos , Ratones , Animales , Oxilipinas/análisis , Espectrometría de Masas en Tándem/métodos , Cromatografía Liquida , Enfermedad del Hígado Graso no Alcohólico/diagnóstico , Biomarcadores
4.
Food Chem ; 424: 136362, 2023 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-37207605

RESUMEN

The current study was to investigate how microwave on flaxseed affected the physicochemical stability and gastrointestinal digestion of oil bodies (OBs) in flaxseed milk. Flaxseed was subjected to moisture adjustment (30-35 wt%, 24 h), and microwave exposure (0-5 min, 700  W). Microwave treatment slightly weakened the physical stability of flaxseed milk indicated by Turbiscan Stability Index, but there were no visual phase separation during 21 days of storage at 4 °C. Upon microwave treatment, OBs experienced the layer-by-layer encapsulation into loose interface embedding by storage protein-gum polysaccharide complex from bulk phase, resulting in lower viscoelasticity of flaxseed milk. The OBs underwent earlier interface collapse and lipolysis during gastrointestinal digestion, followed by synergistic micellar absorption, faster chylomicrons transport within enterocytes of rats fed flaxseed milk. The accumulation of α-linolenic acid and synergistic conversion into docosapentaenoic and docosahexanoic acids in jejunum tissue were achieved accompanied by the interface remodeling of OBs in flaxseed milk.


Asunto(s)
Lino , Ratas , Animales , Leche , Microondas , Digestión , Aceite de Linaza , Ácidos Grasos
5.
Food Chem ; 404(Pt B): 134683, 2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36323028

RESUMEN

This study investigated the impact of multiple thermal treatments (explosion-puffing, microwave, and roasting) on the processing qualities of sesame seeds and cold-pressed oil. The scanning electron microscopy (SEM) showed fissures and cavities of sesame seed surface upon thermal treatments. The microwave treatment promoted the maximum conversion of sesamolin into sesamol in the sesame oil. Compared with other treatments, explosion-puffing treatment resulted in most significant increases in the multiple beneficial phytochemicals, as well as in vitro antioxidant properties determined by 2,2-dipheny1-1-picrylhydrazyl radical (DPPH) radical scavenging activity, Ferric reducing antioxidant power (FRAP) and oxidative stability index (OSI). Additionally, thermal treatment processing caused varying degrees of damage of crude protein, total amino acids (TAA) and protein structure (tertiary and second structure). In which, explosion-puffing achieved minimal reduction in the first two indicators. Collectively, explosion-puffing might be a preferable thermal treatment method for industrial sesame processing with improved quality specifications.


Asunto(s)
Sesamum , Sesamum/química , Antioxidantes , Aceite de Sésamo/química , Oxidación-Reducción , Semillas
6.
J Adv Res ; 45: 31-42, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-35618634

RESUMEN

INTRODUCTION: Diminished brain insulin sensitivity is associated with reduced cognitive function. Docosahexaenoic acid (DHA) is known to maintain normal brain function. OBJECTIVES: This study aimed to determine whether DHA impacts hippocampal insulin sensitivity and cognitive function in aged rats fed a high-fat diet (HFD). METHODS: Eight-month-old female Sprague-Dawley rats were randomly divided into three groups (n = 50 each). Rats in the aged group, HFD group, and DHA treatment group received standard diet (10 kcal% fat), HFD (45 kcal% fat), and DHA-enriched HFD (45 kcal% fat, 1% DHA, W/W) for 10 months, respectively. Four-month-old female rats (n = 40) that received a standard diet served as young controls. Neuroinflammation, oxidative stress, amyloid formation, and tau phosphorylation in the hippocampus, as well as systemic glucose homeostasis and cognitive function, were tested. RESULTS: DHA treatment relieved a block in the insulin signaling pathway and consequently protected aged rats against HFD-induced hippocampal insulin resistance. The beneficial effects were explained by a DHA-induced decrease in systemic glucose homeostasis dysregulation, hippocampal neuroinflammation and oxidative stress. In addition, DHA treatment broke the reciprocal cycle of hippocampal insulin resistance, Aß burden, and tau hyperphosphorylation. Importantly, treatment of model rats with DHA significantly increased their cognitive capacity, as evidenced by their increased hippocampal-dependent learning and memory, restored neuron morphology, enhanced cholinergic activity, and activated cyclic AMP-response element-binding protein. CONCLUSION: DHA improves cognitive function by enhancing hippocampal insulin sensitivity.


Asunto(s)
Resistencia a la Insulina , Ratas , Femenino , Animales , Resistencia a la Insulina/fisiología , Ácidos Docosahexaenoicos/farmacología , Ácidos Docosahexaenoicos/metabolismo , Dieta Alta en Grasa/efectos adversos , Ratas Sprague-Dawley , Enfermedades Neuroinflamatorias , Cognición , Hipocampo/metabolismo , Insulina/metabolismo , Glucosa/metabolismo
7.
ACS Synth Biol ; 11(12): 4171-4183, 2022 12 16.
Artículo en Inglés | MEDLINE | ID: mdl-36454215

RESUMEN

Schizochytrium sp. is commercially used for the production of docosahexaenoic acid (DHA). Some strains of Schizochytrium sp. are also known to produce low amounts of carotenoids, including astaxanthin and ß-carotene. In order to enhance the production of astaxanthin in Schizochytrium sp., we established a seamless genome editing system with a dual selection marker for rapid screening of positive transformants. By using this system, we strengthened the endogenous mevalonate pathway, enhanced the supply of geranylgeranyl diphosphate and ß-carotene, upregulated endogenous ß-carotene hydroxylase, and introduced the algal astaxanthin pathway. The highest astaxanthin production in the engineered Schizochytrium sp. was achieved at 8.1 mg/L (307.1 µg/g dry cell weight) under shake-flask conditions, which was 2.6-fold higher than that in the start strain. Meanwhile, the percentage of DHA to total fatty acids was not obviously affected. We then eliminated the dual selection marker by using the Cre-loxP recombination system, and the engineered strain was ready for iterative editing. The developed system could be applied to seamlessly engineer DHA-producing Schizochytrium sp. toward astaxanthin and other value-added terpenoids, which broadens the application of this strain.


Asunto(s)
Ácidos Docosahexaenoicos , Estramenopilos , Ácidos Docosahexaenoicos/metabolismo , beta Caroteno/metabolismo , Edición Génica , Estramenopilos/genética
8.
Foods ; 11(19)2022 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-36230069

RESUMEN

In this study, an encapsulation system was developed for functional plant oil delivery. Through a series of orthogonal experiments and single factor experiments, the raw material compositions, emulsification conditions, and spray drying conditions for the preparation of flaxseed oil and safflower seed oil powders were optimized, and the final encapsulation efficiency was as high as 99% with approximately 50% oil loading. The storage stability experiments showed that oil powder's stability could maintain its physicochemical properties over six months. Oral supplementation of the spray-dried flaxseed oil powder exhibited a significant and better effect than flaxseed oil on alleviating colitis in C57BL/6J mice. It suppressed the pro-inflammatory cell factors, including IL-6 and TNF-α, and repaired gut microbial dysbiosis by increasing the microbial diversity and promoting the proliferation of probiotic taxa such as Allobaculum. This work suggests that spray-dried flaxseed oil powder has great potential as a nutraceutical food, with spray drying being a good alternative technique to improve its bioactivity.

9.
Front Bioeng Biotechnol ; 10: 951394, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36032715

RESUMEN

The artificial multienzyme systems developed by mimicking nature has attracted much interest. However, precisely controlled compositions and ratios of multienzymatic co-immobilization systems are still limited by the indistinguishable nature of enzymes. Herein, a strategy for fabricating DNA-directed immobilization of horseradish peroxidase (HRP) and glucose oxidase (GOx) on hybrid DNA nanoflowers (GOx-HRP@hDFs) is presented. The preparation of micron-sized hybrid DNA flowers (hDFs) begins with the predetermined repeatable polymer-like DNA sequences which contained two strands. The hDFs structure is generated through one-pot rolling circle amplification (RCA) and self-assembly with magnesium pyrophosphate inorganic crystals. Based on the rigid-base pairing, GOx and HRP conjugated with sequences complementary to strands would be anchored to the predesigned locations, respectively. By adjusting the loading amount/ratio of enzymes properly, the maximal catalytic efficiency can be precisely regulated. The reaction activity of GOx-HRP@hDFs was 7.4 times higher than that of the free GOx-HRP under the optimal mole ratio (GOx/HRP 4:1). In addition, this multienzyme catalyst system exhibits excellent precision, specificity, reproducibility, and long-term storage stability when applied to real human blood samples. The preceding results validate that GOx-HRP@hDFs are promising candidates for personal diabetes detection.

10.
Food Sci Nutr ; 10(6): 1975-1987, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35702282

RESUMEN

In this study, twenty-six peanut varieties and their cold-pressed oils from eleven provinces in China were investigated for their oil content, acid value, peroxide value, fatty acid profiles, bioactive constituents, and induction period (IP) of lipid oxidation. Meanwhile, the effect of the geographical origin of peanut on the quality of cold-pressed peanut oils (CPOs) was studied. The average acid value of CPOs in southern China was higher than that in northern China (0.49 mg KOH/g versus 0.22 mg KOH/g, p > .05). In addition, the average of oleic acid content, ratio of oleic acid to linoleic acid (O/L), and IP were also higher in southern China than that in northern China (p < .05). However, the average content of campesterol, ß-sitosterol, total phytosterol, linoleic acid, and ratio of unsaturated fatty acid to saturated fatty acid (UFA/SFA) exhibited reverse results (p < .05). At last, the comprehensive evaluation of CPOs based on principal component analysis (PCA) was performed. In all samples, Silihong from Liaoning province, northern China was No.1, and Zhonghua 21 from Xiaogan City, Hubei Province was No.4 which was the first one from southern China. Moreover, heat map clustering analysis further revealed the differences and similarities among different samples, and those results were in accordance with the comprehensive evaluation results.

11.
J Agric Food Chem ; 70(12): 3569-3584, 2022 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-35306817

RESUMEN

The plant polyphenols are normally presented as natural functional antioxidants, which also possess the potential ability to improve the physicochemical stability of polyunsaturated fatty acid (PUFA)-enriched emulsions by interface engineering. This review discussed the potential effects of polyphenols on the stability of PUFA-enriched emulsions from the perspective of the molecular thermodynamic antioxidative analysis, the kinetic of interfacial partitioning, and the covalent and non-covalent interactions with emulsifiers. Recently, research studies have proven that the interfacial structure of emulsions can be concurrently optimized via promoting interfacial partitioning of polyphenols and further increasing interfacial thickness and strength. Moreover, the applied limitations of polyphenols in PUFA-enriched emulsions were summarized, and then some valuable and constructive viewpoints were put forward in this review to provide guidance for the use of polyphenols in constructing PUFA-enriched emulsions.


Asunto(s)
Ácidos Grasos Insaturados , Polifenoles , Emulsionantes/química , Emulsiones/química , Ácidos Grasos Insaturados/química , Cinética , Polifenoles/química
12.
J Agric Food Chem ; 70(8): 2673-2683, 2022 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-35191700

RESUMEN

Astaxanthin is a highly value-added keto-carotenoid compound. The astaxanthin 3S,3'S-isomer is more desirable for food additives, cosmetics, and pharmaceuticals due to health concerns about chemically synthesized counterparts with a mixture of three isomers. Biosynthesis of 3S,3'S-astaxanthin suffers from limited content and productivity. We engineered Yarrowia lipolytica to produce high levels of 3S,3'S-astaxanthin. We first assessed various ß-carotene ketolases (CrtW) and ß-carotene hydroxylases (CrtZ) from two algae and a plant. HpCrtW and HpCrtZ from Haematococcus pluvialis exhibited the strongest activity in converting ß-carotene into astaxanthin in Y. lipolytica. We then fine-tuned the HpCrtW and HpCrtZ transcriptional expression by increasing the rounds of gene integration into the genome and applied a modular enzyme assembly of HpCrtW and HpCrtZ simultaneously. Next, we rescued leucine biosynthesis in the engineered Y. lipolytica, leading to a five-fold increase in biomass. The astaxanthin production achieved from these strategies was 3.3 g/L or 41.3 mg/g dry cell weight under fed-batch conditions, which is the highest level reported in microbial chassis to date. This study provides the potential for industrial production of 3S,3'S-astaxanthin, and this strategy empowers us to build a sustainable biorefinery platform for generating other value-added carotenoids in the future.


Asunto(s)
Ingeniería Metabólica , Yarrowia , Xantófilas/química , Yarrowia/genética , Yarrowia/metabolismo , beta Caroteno/metabolismo
13.
ACS Nano ; 16(2): 2198-2208, 2022 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-35142211

RESUMEN

To lower the risk of disease and improve health, many nutrients benefit from intestinal-targeted delivery. Here, we present a nutrient-delivery system based on a pH-responsive "wood scroll", in which nutrients are stored, protected, and controllably released through the rolled structure and natural microchannels of a flexible wood substrate, thus ensuring higher bioactivity as well as prolonged steady release of the nutrient load to the intestine. We loaded the wood's natural microchannels with probiotics as a proof-of-concept demonstration. The probiotic-loaded wood scrolls can survive the simulated conditions of the stomach with a high survival rate (95.40%) and exhibit prolonged release (8 h) of the probiotic load at a constant release rate (4.17 × 108 CFUs/h) in the simulated conditions of the intestine. Moreover, by modifying the macroscopic geometry and microstructures of the wood scrolls, both the nutrient loading and release behaviors can be tuned over a wide range for customized or personalized nutrient management. The wood scrolls can also deliver other types of nutrients, as we demonstrate for tea polyphenols and rapeseed oil. This wood scroll design illustrates a promising structurally controlled strategy for the delivery of enteric nutrients using readily available, low-cost, and biocompatible biomass materials that have a naturally porous structure for nutrient storage, protection, and controlled release.


Asunto(s)
Probióticos , Materiales Biocompatibles , Concentración de Iones de Hidrógeno , Intestinos , Nutrientes , Probióticos/química
14.
Food Chem ; 367: 130741, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34399272

RESUMEN

Volatile sulfur-containing compounds (VSCs) provide an important contribution to foods due to their special odors. In this study, VSCs in 21 cold-pressed rapeseed oils (CROs) from 9 regions in China were extracted and separated by headspace solid-phase microextraction combined with gas chromatography coupled with sulfur chemiluminescence detection. 19 VSCs were identified by authentic standards, and the total concentration of VSCs in all CROs ranged from 49.0 to 18129 µg/kg. Dimethyl sulfide (DMS), with its high odor activity value (7-14574), was the most significant aroma contributor to the CROs. Furthermore, S-methylmethionine (SMM) in rapeseed was first affirmed by ultra-performance liquid chromatography-tandem mass spectrometry and isotope quantitation. The positive correlation coefficient between DMS and SMM was 0.793 (p < 0.05), which confirmed SMM as a crucial precursor of DMS in CROs. This study provided a theoretical basis for selecting rapeseed materials by the distribution of essential VSCs and the source of DMS.


Asunto(s)
Compuestos de Azufre , Compuestos Orgánicos Volátiles , Cromatografía Líquida de Alta Presión , Cromatografía Liquida , Cromatografía de Gases y Espectrometría de Masas , Odorantes/análisis , Aceite de Brassica napus , Sulfuros , Azufre , Compuestos de Azufre/análisis , Espectrometría de Masas en Tándem , Compuestos Orgánicos Volátiles/análisis
15.
Food Chem ; 368: 130802, 2022 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-34411866

RESUMEN

This study aimed to investigate the influences of microwave (MV) exposure to flaxseed on the physicochemical stability of oil bodies (OBs) focused on the interface remodeling. The results showed that the intracellular OBs subjected to absolute rupture and then partial dispersion by protein bodies visualized by TEM following MV exposure (1-5 min; 700 W). After aqueous extraction, native flax OBs manifested excellent spherical particles with completely intact surface and wide particle size distribution (0.5-3.0 µm) examined by cryo-SEM. Upon 1-5 min of MV exposure, the defective interface integrity and beaded morphology were successively observed for flax OBs, accompanied by the impaired physical stability and rheological behavior due to the newly assembled phospholipid/protein interface. Notably, the profitable migration of phenolic compounds effectively suppressed the lipid peroxidation and protein carbonylation in flax OBs. Thus, MV exposure (1-5 min; 700 W) was unfavorable for improving the physical stability of flax OBs.


Asunto(s)
Lino , Aceite de Linaza , Gotas Lipídicas , Microondas , Fenoles , Fosfolípidos
16.
Food Chem ; 373(Pt B): 131607, 2022 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-34819247

RESUMEN

Volatile thiols are important aroma components of rapeseed oil. This study established an identification and quantification method of volatile thiols via headspace solid-phase microextraction and gas chromatography-sulfur chemiluminescence detection. Four thiols (phenylmethanthiol, 3-sulfanyl-1-hexanol, 2-methyl-3-furanthiol, and 2-furylmethanthiol) were newly identified in microwaved rapeseed oil, and cause sesame, roasted meat, and garlic odors. The total concentration of the four thiols in rapeseed oil obtained from 13 rapeseed varieties ranged from 11.47 to 153.72 µg/kg. Determination of the threshold revealed that 3-sulfanyl-1-hexanol possessed the highest odor active value (7565), followed by phenylmethanthiol (3589), 2-furylmethanthiol (626), and 2-methyl-3-furanthiol (28). Further, perceptual interactions between volatile thiols and characteristic odor (3-butenyl isothiocyanate) of rapeseed oil were evaluated by Feller's addition model and S-curve method, which revealed that 2-methyl-3-furanthiol, 2-furylmethanthiol, phenylmethanthiol, and 3-sulfanyl-1-hexanol present a positive effect with 3-butenyl isothiocyanate. This study provides deep insights into the impact of sulfur-containing compounds on the aroma of rapeseed oil.


Asunto(s)
Odorantes , Compuestos Orgánicos Volátiles , Cromatografía de Gases y Espectrometría de Masas , Odorantes/análisis , Olfatometría , Aceite de Brassica napus , Microextracción en Fase Sólida , Compuestos de Sulfhidrilo/análisis , Compuestos Orgánicos Volátiles/análisis
17.
Int J Biol Macromol ; 199: 61-68, 2022 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-34954297

RESUMEN

Here, we present highly porous, cellulose-based microspheres using (2,2,6,6-tetramethylpiperidine-1-oxyl) TEMPO-oxidized cellulose fibers (TOCFs) as starting materials. The TOCFs were first dissolved in a NaOH/urea solvent and transformed into microspheres via an emulsification method. The carboxyl groups on the surface of TOCFs were successfully carried on the cellulose-based microspheres, which provides them numerous reacting or binding sites, allowing them to be easily functionalized or immobilized with biomolecules for multi-functional applications. Furthermore, the introduction of magnetic nanoparticles awards these microspheres magnetic properties, allowing them to be attracted by a magnetic field. As a proof of concept, we demonstrate the application of using these carboxylate cellulose-based microspheres for enzyme immobilization. The cellulose-based microspheres can successfully create stable covalent bonds with enzymes after the activation of carboxyl groups. The enhanced pH tolerance, thermal stability, convenient recovery, and reusability position the emulsified microspheres as promising carriers for enzyme immobilization.


Asunto(s)
Celulosa , Enzimas Inmovilizadas , Celulosa/química , Estabilidad de Enzimas , Enzimas Inmovilizadas/química , Concentración de Iones de Hidrógeno , Microesferas , Porosidad
18.
New Phytol ; 233(4): 1797-1812, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34882804

RESUMEN

Long-chain acyl-CoA synthetases (LACS) play diverse and fundamentally important roles in lipid metabolism. While their functions have been well established in bacteria, yeast and plants, the mechanisms by which LACS isozymes regulate lipid metabolism in unicellular oil-producing microalgae, including the diatom Phaeodactylum tricornutum, remain largely unknown. In P. tricornutum, a family of five genes (ptACSL1-ptACSL5) encodes LACS activities. We generated single lacs knockout/knockdown mutants using multiplexed CRISPR/Cas9 method, and determined their substrate specificities towards different fatty acids (FAs) and subcellular localisations. ptACSL3 is localised in the mitochondria and its disruption led to compromised growth and reduced triacylglycerol (TAG) content when cells were bubbled with air. The ptACSL3 mutants showed altered FA profiles in two galactoglycerolipids and phosphatidylcholine (PC) with significantly reduced distribution of 16:0 and 16:1. ptACSL5 is localised in the peroxisome and its knockdown resulted in reduced growth rate and altered molecular species of PC and TAG, indicating a role in controlling the composition of acyl-CoAs for lipid synthesis. Our work demonstrates the potential of generating gene knockout mutants with the mutation of large fragment deletion using multiplexed CRISPR/Cas9 and provides insight into the functions of LACS isozymes in lipid metabolism in the oleaginous microalgae.


Asunto(s)
Diatomeas , Sistemas CRISPR-Cas/genética , Coenzima A/genética , Coenzima A/metabolismo , Coenzima A Ligasas/genética , Coenzima A Ligasas/metabolismo , Diatomeas/genética , Diatomeas/metabolismo , Ácidos Grasos/metabolismo , Mitocondrias/metabolismo
19.
Food Chem ; 372: 131256, 2022 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-34627092

RESUMEN

In this study, a continuous-flow bioreactor packed with well-organized lipase microarrays was developed for the sustainable synthesis of functional lipid-phytosterol esters (PEs). Hollow mesoporous silicon spheres with a suitable pore size were prepared for lipase immobilization, and the hydrophobic modification endowed the lipase with excellent catalytic activity and stability. The results showed that the condensely packed lipase microarrays offered large specific surface areas and guaranteed the thorough interaction between the lipase and substrates in the continuous-flow bioreactor. Meanwhile, the substrate could pass through the reactor at 1 mL/min with a high conversion of 93.6% due to the hollow structure of the packing spheres. Moreover, the reactors were able to produce 1564 g PEs/g catalyst in a continuous 30-day processing period, which set the highest records for PEs synthesis. This sustainable and highly-converting flow system provided a feasible path for scale-up production of PEs in the food processing area.


Asunto(s)
Lipasa , Fitosteroles , Reactores Biológicos , Enzimas Inmovilizadas/metabolismo , Esterificación , Ésteres , Lipasa/metabolismo , Fitosteroles/metabolismo
20.
Front Nutr ; 9: 1081717, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36726819

RESUMEN

Introduction: Taking antibiotics would interfere with gut microbiota and increase the risk of opportunistic pathogen infection and inflammation. Methods: In this study, 36 male C57BL/6 mice were divided into 4 groups (n = 9) to investigate whether two kinds of algal oil could alleviate the intestinal damage induced by CS (Ceftriaxone sodium). These algal oils were obtained from Schizochytrium sp. cultures using Yeast extract (YE) and Rapeseed meal (RSM) as substrate, respectively. All tested mice were administrated with CS for 8 days and then the colon pathological morphology, the expression levels of inflammatory factors and the gut microbial profile were analyzed in mice supplemented with or without algal oil. Results: The results showed that both YE and RSM algal oils markedly reduced mucosal damage and intestinal inflammatory response in CS-treated mice by inhibiting the pro-inflammatory cytokine tumor necrosis factor (TNF)-α, interleukin (IL)-6 and myeloperoxidase (MPO) activity. In addition, fluorescence immunohistochemistry showed that the tight junction protein ZO-1 was increased in mice supplemented with YE and RSM algal oil. Furthermore, YE algal oil promoted the beneficial intestinal bacteria such as Lachnospiraceae and S24_7 compared with the CS group, while supplementation with RSM algal oil enriched the Robinsoniella. Spearman's correlation analysis exhibited that Melissococcus and Parabacteroides were positively correlated with IL-6 but negatively correlated with IL-10. Discussion: This study suggested that supplementation with algal oil could alleviate intestinal inflammation by regulating gut microbiota and had a protective effect on maintaining intestinal barrier against antibiotic-induced damage in mice.

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