Enzymatic hydrolysis

酶水解
  • 文章类型: Journal Article
    当母乳喂养对牛奶过敏的婴儿不可行时,使用基于水解牛奶蛋白的婴儿配方。大多数患有牛奶过敏(CMA)的儿童对骆驼奶的耐受性良好,可能是CMA管理的替代品。在这里,我们旨在评估加工对免疫原性的影响,致敏,牛乳和骆驼乳的抗体结合和交叉反应能力。牛乳和骆驼乳通过酶水解或热处理进行处理。棕色挪威大鼠用PBS免疫,非处理,酶水解或热处理的奶牛或骆驼奶。进行体内测试以评估临床体征。分析血液和粪便样品的抗体应答水平和特异性。牛乳和骆驼乳表现出相似的致敏能力。加工降低了牛奶的致敏能力,然而,只有酶水解而不是热处理降低了骆驼奶的致敏能力。加工影响了大鼠体内抗体的特异性,虽然奶牛和骆驼奶的效果不同。该研究表明,奶牛和骆驼奶之间的交叉反应性较低,随着加工的减少,这表明骆驼奶的加工可能会提高其在CMA管理中的有效性。
    Infant formulas based on hydrolysed cow\'s milk proteins are used when breastfeeding is not feasible in cow\'s milk allergic infants. Camel milk has been shown to be well-tolerated by the majority of children with cow\'s milk allergy (CMA) and may be a substitute in management of CMA. Here we aimed to evaluate the impact of processing on immunogenicity, sensitising, antibody-binding and cross-reactive capacity of cow\'s and camel milk. Cow\'s and camel milk were processed by means of enzyme hydrolysis or heat treatment. Brown Norway rats were immunised with PBS, non-processed, enzyme hydrolysed or heat-treated cow\'s or camel milk. In vivo tests were performed for evaluation of clinical signs. Blood and faecal samples were analysed for levels and specificity of antibody responses. Cow\'s and camel milk showed similar sensitising capacity. Processing decreased the sensitising capacity of cow\'s milk, yet only enzyme hydrolysis but not heat treatment decreased the sensitising capacity of camel milk. Processing affected the specificity of antibodies raised in the rats, though the effect differed between cow\'s and camel milk. The study showed a low cross-reactivity between cow\'s and camel milk, which was decreased with processing, suggesting that processing of camel milk may improve its usefulness in CMA management.
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  • 文章类型: Journal Article
    纤维素纳米晶体(CNCs)是从纤维素纤维分离的结晶域。它们已被用于广泛的应用,如增强填料,抗菌剂和生物传感器的制造。在这种背景下,这项工作的目的是使用两种不同的方法结合研磨预处理来获得和分析从细菌纳米纤维素(BNC)提取的CNCs:使用64%硫酸的酸性水解和使用商业纤维素酶混合物的酶促水解。观察到从酶途径获得的CNCs(e-CNCs)是直径为56±11nm的球形纳米颗粒。相比之下,来自酸水解的CNCs(a-CNCs)表现为具有高纵横比的针状纳米粒子,其长度/宽度为158±64nm/11±2nm。a-CNCs的表面ζ电位(ZP)为-30,8mV,而e-CNCs的电势为+2.70±3.32mV,表明a-CNCs由带负电荷的颗粒组成,在溶液中具有较高的稳定性。虽然酸性途径导致纳米晶体与酶途径相比具有略高的结晶度指数,发现e-CNCs比BNC和a-CNCs更热稳定。这里,我们还使用L929细胞系证实了a-CNCs和e-CNCs的安全性.最后,本文介绍了两种不同的CNCs合成方法,这些方法导致形成不同尺寸的纳米颗粒,形态和独特的物理化学性质。据我们所知,这是第一个研究产生球形纳米颗粒作为BNC酶处理的结果。
    Cellulose nanocrystals (CNCs) are crystalline domains isolated from cellulosic fibers. They have been utilized in a wide range of applications, such as reinforcing fillers, antibacterial agents and manufacturing of biosensors. Whitin this context, the aim of this work was to obtain and analyze CNCs extracted from bacterial nanocellulose (BNC) using two distinct methods combined with milling pre-treatment: an acidic hydrolysis using 64 % sulfuric acid and an enzymatic hydrolysis using a commercial cellulase enzyme mixture. The CNCs obtained from the enzymatic route (e-CNCs) were observed to be spherical nanoparticles with diameter of 56 ± 11 nm. In contrast, the CNCs from the acid hydrolysis (a-CNCs) appeared as needle-shaped nanoparticles with a high aspect ratio with lengths/widths of 158 ± 64 nm/11 ± 2 nm. The surface zeta potential (ZP) of the a-CNCs was -30,8 mV, whereas the e-CNCs has a potential of +2.70 ± 3.32 mV, indicating that a-CNCs consisted of negatively charged particles with higher stability in solution. Although the acidic route resulted in nanocrystals with a slightly higher crystallinity index compared to the enzymatic route, e-CNCs was found to be more thermally stable than BNC and a-CNCs. Here, we also confirmed the safety of a-CNCs and e-CNCs using L929 cell line. Lastly, this article describes two different CNCs synthesis approaches that leads to the formation of nanoparticles with different dimensions, morphology and unique physicochemical properties. To the best of our knowledge, this is the first study to yield spherical nanoparticles as a result of BNC enzymatic treatment.
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  • 文章类型: Journal Article
    本研究开发了一种新型的生物炭增强酶促方法,用于将食物垃圾快速转化为固体和液体生物肥料。通过用10%的生物炭增强和用5%的食物垃圾衍生的水解酶混合物(即真菌糊状物)介导,100公斤餐厨垃圾可转化为22.3公斤含水量为30%的固体生物肥料和55.0公斤液体生物肥料,符合中国固体和液体有机生物肥料的国家标准,分别。田间种植结果表明,在食物垃圾衍生的生物肥料上种植的白菜与商业肥料相当,在蔬菜生产力和营养成分方面。进一步表明,餐厨垃圾生物肥料的应用并未改变土壤化学性质,但丰富了微生物多样性。这项研究清楚地表明,将食物垃圾转化为生物肥料的生物炭增强酶促方法在技术上是可行的,对循环农业经济而言是经济可行的。
    The present study developed a novel biochar-augmented enzymatic approach for fast conversion of food waste to solid and liquid biofertilizers. By augmented with 10 % of biochar and mediated with 5 % of food waste-derived hydrolytic enzymes mixture (i.e. fungal mash), 100 kg of food waste could be converted into 22.3 kg of solid biofertilizer with a water content of 30 % and 55.0 kg of liquid biofertilizer, which fulfilled Chinese national standards for solid and liquid organic biofertilizers, respectively. Field plantation results showed that the Pak Choi grown on food waste-derived biofertilizers was comparable with that on commercial ones, in terms of the vegetable productivity and nutrient contents. It was further revealed that the application of food waste-derived biofertilizers did not change soil chemical properties but enriched microbial diversity. This study clearly indicated that the biochar-augmented enzymatic approach for food waste conversion to biofertilizers was technically feasible and economically viable towards circular agriculture economy.
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  • 文章类型: Journal Article
    在这项研究中,研究了超声辅助酶解对猪骨胶原抗炎肽提取的影响。结果表明,超声处理增加了α-螺旋的含量,减少了β-链和无规卷曲,促进小分子肽的生成。超声辅助酶解提高了多肽含量,ABTS+自由基清除和亚铁离子螯合能力比非超声组增强。超声功率450W(20min),肽具有显著的抗炎活性,白细胞介素-6(IL-6)的释放,在脂多糖(LPS)诱导的RAW264.7细胞中,肿瘤坏死因子-α(TNF-α)均受到抑制。用LC-MS/MS分析后,通过PeptideRanker和分子对接选择了8种具有潜在抗炎活性的肽。总的来说,超声辅助酶解是从猪骨中提取生物活性肽的有效策略,首先证明了骨胶原源肽的炎症调节能力。
    In this study, the effects of ultrasound-assisted enzymatic hydrolysis on the extraction of anti-inflammatory peptides from porcine bone collagen were investigated. The results showed that ultrasound treatment increased the content of α-helix while decreased β-chain and random coil, promoted generation of small molecular peptides. Ultrasound-assisted enzymatic hydrolysis improved the peptide content, enhanced ABTS+ radical scavenging and ferrous ion chelating ability than non-ultrasound group. At the ultrasonic power of 450 W (20 min), peptides possessed significant anti-inflammatory activity, where the releasing of interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) was all suppressed in lipopolysaccharide (LPS) induced RAW264.7 cells. After the analysis with LC-MS/MS, eight peptides with potential anti-inflammatory activities were selected by the PeptideRanker and molecular docking. In general, the ultrasound-assisted enzymatic hydrolysis was an effective strategy to extract the bioactive peptides from porcine bone, and the inflammatory regulation capacity of bone collagen sourced peptides was firstly demonstrated.
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  • 文章类型: Journal Article
    真菌毒素是由真菌产生的有毒物质,经常,不同的霉菌毒素在食品中共存。曲霉毒素A(OTA)和曲霉毒素B(OTB)可能在多种食物中共存,比如红葡萄酒和小麦,存在显著的人口暴露风险。在这项研究中,我们调查了五种脂肪酶(假丝酵母脂肪酶,南极念珠菌B脂肪酶,蓝藻热霉菌脂肪酶,来自黑曲霉(ANL)和猪胰脂肪酶(PPL)的Amano脂肪酶A)将OTA和OTB水解为非危险产品。只有ANL和PPL降解了两种底物,然而,具有不同程度的效率。PPL完全降解的OTB(9小时),但只有43%的OTA(25小时)。分子模拟表明OTA与PPL的结合能很高,这可以用氯基团的影响来解释,损害水解。ANL能够完全降解两种真菌毒素,OTA在3h和OTB在10h。ANL酶也显示出对OTA的高特异性,然而,这种酶的活性不受氯的影响,并且比OTB更快地水解OTA。这两种酶被发现能够解毒共存的曲霉毒素A和B,使分离的酶成为直接使用微生物缓解食品中霉菌毒素的替代方法。
    Mycotoxins are toxic substances produced by fungi and, frequently, different mycotoxins cooccur in food commodities. Ochratoxin A (OTA) and Ochratoxin B (OTB) may co-occur in a variety of foods, like red wines and wheat, presenting a significant risk of population exposure. In this study, we investigated the potential of five lipases (Candida rugosa Lipase, Candida antarctica B Lipase, Thermomyces lanuginosus Lipase, Amano Lipase A from Aspergillus niger (ANL) and Porcine Pancreas Lipase (PPL)) to hydrolyze OTA and OTB into non-hazardous products. Only ANL and PPL degraded both substrates, however, with varying degrees of efficiency. PPL completely degraded OTB (9 h), but only 43% of OTA (25 h). Molecular simulations indicated a high binding energy of OTA to PPL, that can be explained by the impact of the chlorine group, impairing hydrolysis. ANL was able to completely degrade both mycotoxins, OTA in 3 h and OTB in 10 h. The ANL enzyme showed also high specificity to OTA, however, the activity of this enzyme is not affected by chlorine and hydrolyzes OTA faster than OTB. These two enzymes were found to be able to detoxify co-occurring ochratoxins A and B, making isolated enzymes an alternative to the direct use of microorganisms for mycotoxin mitigation in food.
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  • 文章类型: Journal Article
    由于环境问题,以及其卓越的物理和机械能力,生物降解性,以及光学和屏障质量,纳米纤维素作为纳米尺寸的增强材料的来源引起了极大的兴趣。本文主要研究如何在不同浓度下,在纤维素酶和木聚糖酶等酶的存在下,使用不同类型的酸如H2SO4和HCl从棉花中制造纤维素纳米材料。在酸和酶水解之前使用两种不同类型的漂白方法。在第一种方法中,通过用H2O2漂白棉花来提取纤维素。在第二种方法中,使用NaOCl。对于这两种方法,使用不同浓度的酸和酶来分离纳米纤维素材料,纤维素纳米晶体(CNC),和纤维素纳米原纤维(CNF)在不同的温度。所有获得的纳米纤维素材料通过不同的技术,如FT-IR,Zeta电位,DLS,拉曼光谱,TGA,DSC,XRD,和SEM。借助拉曼和FT-IR光谱证实了与纤维素纳米晶体(CNC)相关的特征信号。根据XRD结果,样品的结晶度百分比范围从54.1%到63.2%。SEM图像显示长纤维分解成小纤维并且在纤维的表面上看到针状特征。使用不同类型的漂白对样品的热稳定性没有显著影响。结果表明,通过酶水解从棉花合成纤维素纳米原纤维(CNF)的成功方法,但结果还表明,漂白方法的选择对CNC和CNF样品的流体动力学性能和结晶度有显著影响。
    Due to environmental concerns, as well as its exceptional physical and mechanical capabilities, biodegradability, and optical and barrier qualities, nanocellulose has drawn a lot of interest as a source of reinforcing materials that are nanometer sized. This article focuses on how to manufacture cellulose nanomaterials from cotton by using different types of acids such as H2SO4 and HCI in different concentrations and in the presence of enzymes such as cellulase and xylanase. Two different types of bleaching methods were used before acid and enzyme hydrolysis. In the first method, cellulose was extracted by bleaching the cotton with H2O2. In the second method, NaOCl was utilized. For both methods, different concentrations of acids and enzymes were used to isolate nanocellulose materials, cellulose nanocrystals (CNC), and cellulose nanofibrils (CNF) at different temperatures. All obtained nanocellulose materials were analyzed through different techniques such as FT-IR, Zeta potentials, DLS, Raman spectroscopy, TGA, DSC, XRD, and SEM. The characteristic signals related to cellulose nanocrystals (CNC) were confirmed with the aid of Raman and FT-IR spectroscopy. According to the XRD results, the samples\' crystallinity percentages range from 54.1% to 63.2%. The SEM image showed that long fibers break down into small fibers and needle-like features are seen on the surface of the fibers. Using different types of bleaching has no significant effect on the thermal stability of samples. The results demonstrate a successful method for synthesizing cellulose nanofibrils (CNF) from cotton through enzymatic hydrolysis, but the results also demonstrated that the choice of bleaching method has a significant impact on the hydrodynamic properties and crystallinity of both CNC and CNF samples.
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  • 文章类型: Journal Article
    BACKGROUND: Organosolv pretreatment is one of the most efficient methods for delignification and boosting biomass saccharification. As compared to typical ethanol organosolv pretreatments, 1,4-butanediol (BDO) organosolv pretreatment is a high-boiling-point solvent pretreatment, which can generate low pressure in the reactor during high temperature cooking that improves the operation safety. Although several studies showed that organosolv pretreatment can lead to effective delignification and enhancement in glucan hydrolysis, there has been no studies on acid- and alkali-catalyzed BDO pretreatment, as well as their comparison on promoting biomass saccharification and lignin utilization.
    RESULTS: It was shown that BDO organosolv pretreatment was more effective in removing lignin from poplar as compared with typical ethanol organosolv pretreatment under the same pretreatment conditions. HCl-BDO pretreatment with 40 mM acid loading led to 82.04% of original lignin removed from biomass, as compared to the lignin removal of 59.66% in HCl-Ethanol pretreatment. Besides, acid-catalyzed BDO pretreatment was more effective in improving the enzymatic digestibility of poplar than alkali-catalyzed BDO pretreatment. As a result, HCl-BDO with acid loading of 40 mM provided a good enzymatic digestibility of cellulose (91.16%) and the maximum sugar yield of 79.41% from original woody biomass. The linear correlations between physicochemical structure (e.g., fiber swelling, cellulose crystallinity, crystallite size, surface lignin coverage and cellulose accessibility) changes of BDO pretreated poplar and enzymatic hydrolysis were plotted to figure out the main factors that influenced biomass saccharification. Moreover, acid-catalyzed BDO pretreatment mainly brought about the phenolic hydroxyl (PhOH) groups formation in lignin structure, while alkali-catalyzed BDO pretreatment mostly led to the lower molecular weight of lignin.
    CONCLUSIONS: Results indicated that the acid-catalyzed BDO organosolv pretreatment could significantly improve enzymatic digestibility of the highly recalcitrant woody biomass. The great enzymatic hydrolysis of glucan resulted from increased cellulose accessibility, which mostly associated with the higher degree of delignification and hemicellulose solubilization, as well as the more increase in fiber swelling. Besides, lignin was recovered from the organic solvent, which could be used as natural antioxidants. The formation of phenolic hydroxyl groups in lignin structure and the lower molecular weight of lignin contributed to its greater radical scavenging capacity.
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  • 文章类型: Journal Article
    稻草是用于生产乙醇的廉价碳水化合物来源的合适替代品。对于预处理效率,测试不同的氢氧化钠浓度(0.5-2.5%w/v)。与其他浓度相比,用2%NaOH(w/v)处理的稻草产生更多的糖(8.17±0.01mg/ml)。碱处理诱导生物质的有效脱木质素和溶胀。用2%氢氧化钠(w/v)预处理稻草可以实现55.34%的脱木质素和53.30%的纤维素富集。当前的研究表明,黑曲霉粗纤维素分解制剂的有效性导致80.51±0.4%纤维素水解。使用产乙醇的酿酒酵母(酵母)和运动发酵单胞菌(细菌)对稻草水解物进行发酵。总的来说,与细菌菌株39.18±0.5%相比,酵母获得了更高的糖转化为乙醇的效率70.34±0.3%。目前的研究表明,用氢氧化钠预处理是一种从稻草和酵母菌株生产乙醇的有效方法。
    Rice straw is a suitable alternative to a cheaper carbohydrate source for the production of ethanol. For pretreatment efficiency, different sodium hydroxide concentrations (0.5-2.5% w/v) were tested. When compared to other concentrations, rice straw processed with 2% NaOH (w/v) yielded more sugar (8.17 ± 0.01 mg/ml). An alkali treatment induces effective delignification and swelling of biomass. The pretreatment of rice straw with 2% sodium hydroxide (w/v) is able to achieve 55.34% delignification with 53.30% cellulose enrichment. The current study shows the effectiveness of crude cellulolytic preparation from Aspergillus niger resulting in 80.51 ± 0.4% cellulose hydrolysis. Rice straw hydrolysate was fermented using ethanologenic Saccharomyces cerevisiae (yeast) and Zymomonas mobilis (bacteria). Overall, superior efficiency of sugar conversion to ethanol 70.34 ± 0.3% was obtained with the yeast compared to bacterial strain 39.18 ± 0.5%. The current study showed that pretreatment with sodium hydroxide is an effective method for producing ethanol from rice straw and yeast strain S. cerevisiae having greater fermentative potential for bioethanol production than bacterial strain Z. mobilis.
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  • 文章类型: Journal Article
    可生物降解的聚合物为全球塑料问题提供了有希望的替代方案,尤其是在过去的十年中,微塑料问题。第一次,通过两阶段熔融缩聚程序通过原位聚合制备含有1、2.5和5wt%生物炭(BC)的聚(丁二酸丁二醇酯)(PBSu)生物复合材料样品。BC被用作PBSu的填料,以提高其机械性能,热转换,和生物降解性。通过1H和13C核磁共振(NMR)和X射线衍射(XRD)检查合成聚合物的结构,并估算分子量,同时也采用差示扫描量热法(DSC)和闪光分析(LFA)来记录热转变并评估热导率,分别。发现BC的量不影响PBSu生物复合材料的分子量。BC的精细分散,以及聚合物基质中BC含量的增加,显著提高了拉伸和冲击强度。DSC分析结果表明,BC促进了PBSu生物复合材料的结晶。由于后者,记录了热扩散率和电导率的温和和系统的增加,表明BC是一种导电材料。PBSu的分子迁移率,局部和分段,生物复合材料没有显著变化,而BC似乎引起总介电常数的增加。最后,发现生物复合材料的酶水解降解速率随着BC含量的增加而增加。
    Biodegradable polymers offer a promising alternative to the global plastic problems and especially in the last decade, to the microplastics problems. For the first time, samples of poly(butylene succinate) (PBSu) biocomposites containing 1, 2.5, and 5 wt% biochar (BC) were prepared by in situ polymerization via the two-stage melt polycondensation procedure. BC was used as a filler for the PBSu to improve its mechanical properties, thermal transitions, and biodegradability. The structure of the synthesized polymers was examined by 1H and 13C nuclear magnetic resonance (NMR) and X-Ray diffraction (XRD) along with an estimation of the molecular weights, while differential scanning calorimetry (DSC) and light flash analysis (LFA) were also employed to record the thermal transitions and evaluate the thermal conductivity, respectively. It was found that the amount of BC does not affect the molecular weight of PBSu biocomposites. The fine dispersion of BC, as well as the increase in BC content in the polymeric matrix, significantly improves the tensile and impact strengths. The DSC analysis results showed that BC facilitates the crystallization of PBSu biocomposites. Due to the latter, a mild and systematic increase in thermal diffusivity and conductivity was recorded indicating that BC is a conductive material. The molecular mobility of PBSu, local and segmental, does not change significantly in the biocomposites, whereas the BC seems to cause an increase in the overall dielectric permittivity. Finally, it was found that the enzymatic hydrolysis degradation rate of biocomposites increased with the increasing BC content.
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  • 文章类型: Journal Article
    在蛋黄免疫球蛋白(IgY)提取过程中,冻融蛋黄颗粒(FYP)可能作为副产物产生。FYP含有许多优质的营养成分,如新鲜蛋黄,但是由于在IgY提取过程中冷冻处理导致的蛋白质变性,因此其功能较差。为了综合利用蛋黄资源,用alcalase对FYP进行酶促水解以产生具有250、500、1000和2000U/g四种酶浓度的FYP水解产物(FYPh),以改善功能特性。然后将FYPh喷雾干燥以获得水解的蛋黄颗粒粉末(HYP)。溶解度,研究了HYP的乳化性能和表面疏水性。结果表明,酶水解可导致表面疏水性发生显著变化,微观结构,HYP的溶解度和乳化性能与未经酶解处理的对照组相比。溶解度和乳化稳定性指数通常从19g/100g增加,12.33至87g/100g,76.63随着水解程度的增加,分别。研究表明,当酶添加量达到1000U/g时,可以有效改善FYP的功能特性。在此条件下制备的HYP具有理想的溶解度和乳化作用,在食品工业中具有应用潜力。
    Freeze-thaw egg yolk pellet (FYP) could be produced as a by-product in the process of egg yolk immunoglobulin (IgY) extraction. The FYP contained many superior nutritional components like fresh egg yolk, but it has poor functionalities because of protein denaturation resulted from freezing treatment during IgY extraction. For the purpose of comprehensive utilization of egg yolk resources, FYP was subjected to enzymatic hydrolysis with alcalase to produce FYP hydrolysates (FYPh) with four enzyme concentrations of 250, 500, 1000 and 2000 U/g for improved functional properties. And then FYPh was spray dried to obtain hydrolyzed egg yolk pellet powder (HYP). Solubility, emulsifying property and surface hydrophobicity of HYP were investigated. The results showed that enzymatic hydrolysis could lead to noticeable changes in surface hydrophobicity, microstructure, solubility and emulsifying properties of HYP compared with the control group without enzymatic hydrolysis treatment. Solubility and emulsification stability index generally increased from 19 g/100 g, 12.33 to 87 g/100 g, 76.63 with increasing degree of hydrolyze, respectively. This study demonstrated that the functional properties of FYP could be effectively improved when the enzyme addition amount reached 1000 U/g. HYP prepared under this condition owes desirable solubility and emulsification, and has the potential of application in food industry.
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