Analysis of Influencing Factors in Production of Selenium-enriched Eggs

Selenium is an essential trace element for human health.Eating selenium-enriched eggs is conducive to easily and effectively solving the problem of selenium deficiency.In the production process of selenium-enriched eggs,different selenium sources,additive doses,feeding time,and the addition of other vitamins,trace elements,and methionine in the diet will influence the deposition of selenium in eggs.Through this review,it is intended to provide a reference for the practical,safe and economical production of selenium-enriched eggs.

Effects of Raising Chickens Under Moringa oleifera Forests on Soil Nutrients and Selenium Absorption by M. oleifera

[Objectives]This study was conducted to investigate the effects of raising chickens under Moringa oleifera forests on soil nutrient changes and selenium absorption by M.oleifera.[Methods]The nutrient contents of the soil and the selenium contents of different parts of M.oleifera were determined and analyzed.[Results]Raising chickens under the investigated M.oleifera forest improved the soil.Compared with the control,the soil organic matter,hydrolyzable nitrogen,available phosphorus,and available potassium of the plots for underforest chicken raising were significantly improved;the changes were the most significant within the range of 2 m from the chicken houses,respectively,and the values were 1.39,1.38,1.52 and 1.31 times of the control,respectively;soil bulk density decreased,total porosity increased,soil structure and permeability improved,and soil pH values at 2 and 5 m away from the chicken houses were significantly higher than the control by 0.34 and 0.28 unit,respectively;and raising chickens under the forest promoted the absorption and utilization of selenium in M.oleifera,and the selenium contents in stems and leaves of M.oleifera were 1.64 times and 1.51 times of the control,respectively.[Conclusions]This study provides a theoretical basis for the high-value selenium-enriching compound economic model of raising chickens under M.oleifera forests.

Selenium Content and Antioxidant Potential of Some Edible Wild Mushrooms from Bandundu Area, DR Congo

Nutrition is an important aspect of public health because it is linked to many significant diseases and health problems. This work is part of the promotion of traditional foods from the Democratic Republic of Congo in general and in the province of Bandundu, in particular by assessing the selenium content and the antioxidant capacity of wild edible mushrooms. Methanolic extracts from selected mushrooms were characterized for their chemical fingerprint by TLC and their in vitro antioxidant activities using ABTS, DPPH assays. Phytochemical screening revealed the presence of alkaloids, free amines, steroids and terpenes in all species. However, Auricularia delicata and Pleurotus tuberregium contain flavonoids. All extracts displayed a good radical-scavenging activity at the concentration range 1 - 300 μg/mL in the following order: Auricularia delicata > Lentinus cf cladopus > Pleurotus tuberregium > Marasmius buzungolo > Schizophillum commune. Studied mushrooms showed the interest quantity of selenium and L. cf cladodus had the highest concentration. Moderate selenium content of these wild mushrooms associated with their important antioxidant activities could provide health benefits to Bandundu’s populations in protecting against oxidative damage under different conditions including konzo.

Effects of selenium and sulfur on antioxidants and physiological parameters of garlic plants during senescence

A hydroponic study was conducted to determine the effects of selenium（Se： 0, 3, 6 μmol L^-1） on senescence-related oxidative stress in garlic plants grown under two sulfur（S） levels. We evaluated the yields of plants harvested at 160 and 200 days after sowing. Plants grown under a low Se dose（0.3 μmol L^-1） at low S level showed higher yields（12.0% increase in fresh weight yield, 13.7% increase in dry weight yield） than the controls, despite a decrease in chlorophyll concentration. Compared with control plants, the Se-treated plants showed lower levels of lipid peroxidation. The Se-treated plants also showed higher activities of glut athione peroxidase and catalase, but lower superoxide dismutase activities. Changes in Fv/Fm values and proline contents were affected more strongly by S than by Se. On the basis of our results, we can conclude that Se plays a key role in the antioxidant systems in garlic seedlings. It delays senescence by alleviating the peroxide stress, but it can be toxic at high levels. A high S level may increase tolerance to high Se concentrations through reducing Se accumulation in plants.

Study on the Activation Effect of Fermented Organic Fertilizers on Selenium in the Soil of Southern Dragon Fruit Orchards

[Objectives]This study was conducted to explore the effects of using fermented organic fertilizers such as cow manure on the activity of selenium in the soil.[Methods]The project team applied the organic fertilizer prepared by fermenting cow manure and other raw materials to activate selenium in the soil at two dragon fruit orchard bases in Shilong Town,Guiping City and Dingdang Town,Long an County,and carried out many years of experiments.[Results]The contents of available selenium in the two experimental orchards in Shilong Town and Dingdang Town increased by 10%and 5%,respectively,and the selenium contents in dragon fruit increased by 228.6%and 200.0%,respectively.[Conclusions]The application of fermented organic fertilizers such as cow manure can increase available selenium content in the soil,thereby increasing the selenium content of dragon fruit.

Synthesis and Characterization of Some Selenium Nanometric Compounds: Spectroscopic, Biological and Antioxidant Assessments

Selenium (IV) vitamin A complex as antioxidant drug design was prepared and characterized by microanalysis, conductance, infrared spectra, Raman laser spectra, 1HNMR spectra, scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and thermogravimetric (TG/DTG and DTA) tool of analyses. Vitamin A chelate was coordinated as a mono-dentate ligand through the oxygen atom of –OH hydroxyl group. Thermal degradation analyses discussed the removal of terminal methyl molecules in the first and second decomposition stage while the organic ligand moieties existed in the third and subsequence steps. The Se (IV) complex in comparable with free vitamin A ligand has been assessed against some kinds of bacteria and fungi which gave a significant inhibition. The surface morphology and nano scale size of selenium metal and its vitamin complex were proved. The activation energy and other thermodynamic parameters (ΔH*, ΔS* and ΔG*) of Se (IV) complex were calculated using Coats-Redfern and Horowitz-Metzger equations.

土壤中硒元素来源和迁移作用研究现状

自然过程和人为因素可以活化和迁移硒进入和离开土壤。查明土壤中硒的来源和迁移作用对富硒土地管理和富硒产业开发具有科学上和实践上的重要意义。岩石圈和大气干湿沉降是土壤硒的最基本来源。地表水径流、地下水淋滤、农作物收割、植物和微生物的挥发是土壤硒丢失的主要途径。土壤中硒的迁移作用可归因于水动力迁移作用、固相吸附作用和动植物循环作用。土壤组成和物理化学条件是控制土壤中硒分布和迁移的直接因素,气候、地形和农业活动通过改变土壤组成和物理化学条件间接地影响土壤中硒的迁移和重分布。在区域尺度(如大洲、国家和省)上,地质背景、气候和地形因素对硒的分布至关重要,而在局部尺度(如县、乡和农田)上,人类活动特别是农业耕作的影响更为显著。基于硒在土壤中的行为特性,提出了一系列硒资源管理策略:1)生物强化和修复,通过动植物循环作用来调节土壤中硒分布和生物有效性,它被认为是一种生态富硒手段;2)灌溉模式,通过改变水动力条件来调整土壤的理化条件,进而改变土壤的固相吸附作用和动植物循环作用,其中漫水灌溉和有氧灌溉结合的水管理模式被认为可以提升土壤硒的有效性;3)农艺措施,如施加硒肥、磷肥、硫肥和撒石灰,通过直接改变土壤组成和理化条件调整土壤硒的分布和有效性,这是传统的富硒农艺措施,但也可能产生一定的生态风险。

Relations between the Elemental Composition Hens＇ Eggs and Feeds

Hens＇ eggs and corresponding feeds were sampled at commercial farms. The eggs were separated into egg yolk and egg white and freeze dried. After pressure digestion, total element contents of Ca, P, Mg, S, Na, Fe, Mn, Zn, Sr, Cu and Ba were detected by ICP-OES in the eggs, whereas, Pb, Ni, Sb, Sn, AI, Cd, Cr, Mo and V were all or largely below the detection limits. In addition, iodine was done by ICP-MS and Se after ashing with Mg-nitrate by hydride-generation-AAS. There were significant accumulations of P, S, Se and I in the egg yolk versus feed levels, as well as S and Na in the egg white. Just a few correlations between concentrations in feed and egg white resp. egg yolk were detected, indicating regulation mechanisms by homeostasis. Strontium showed the strongest trends between feeds and egg white and egg yolk, whereas, there was none for calcium. Among the main elements in the feeds, sulfur had the strongest effects on the egg compositions, e.g., on iodine and iron in the yolk and on sodium in the white, some of them might be non-linear.

富硒纳豆芽孢杆菌发酵鹰嘴豆风味物质和活性成分研究

为了评价富硒纳豆芽孢杆菌发酵鹰嘴豆风味和活性成分,研究了富硒纳豆芽孢杆菌固态和液态发酵鹰嘴豆所产生的挥发性物质、游离氨基酸及其他活性物质组成和含量。结果表明,纳豆芽孢杆菌液态发酵鹰嘴豆(L-SD1)的主要挥发性成分是2-甲基丁酸和3-甲基丁酸,纳豆芽孢杆菌固态发酵鹰嘴豆(G-SD1)、富硒纳豆芽孢杆菌液态发酵(L-Se-SD1)及固态发酵鹰嘴豆(G-Se-SD1)的最主要挥发性成分均为2,5-二甲基吡嗪。液态发酵比固态发酵所产生的挥发性物质种类较多,富硒对主要挥发性物质的种类和相对含量影响较大(P<0.05)。采用氨基酸自动分析仪法检测出L-SD1、L-Se-SD1、G-SD1和G-Se-SD1中均含有16种氨基酸,包括7种人体必需氨基酸和9种其他氨基酸,且苦味氨基酸含量均最高。不同发酵方式对氨基酸种类影响无差异;液态发酵比固态发酵产生的总游离氨基酸含量高。富硒纳豆芽孢杆菌液态发酵鹰嘴豆总黄酮含量为(1.91±0.02)mg/mL,维生素K 2含量为(755.70±0.11)μg/100 g,卵磷脂质量分数为(2.41±0.03)%,相比于未富硒组,分别提高了80.2%、81.6%、10.6%。

羊肚菌硒化多糖结构表征及抗运动疲劳作用

目的:研究羊肚菌硒多糖的结构特征及其对运动疲劳大鼠的改善作用。方法:采用超声波辅助热水提取羊肚菌子实体多糖,经DEAE纤维素柱层析和葡聚糖凝胶G-100柱层析洗脱得到纯化多糖(Msp-1),采用硝酸-亚硒酸钠法处理纯化多糖得到羊肚菌硒化多糖(Se-Msp1),分别对Msp-1和Se-Msp1结构表征;通过力竭游泳试验测定大鼠的游泳时间,同时建立大鼠负重游泳模型,设置安静对照组、运动疲劳对照组、阳性对照组(红景天苷,100 mg/kg)、普通多糖组(Msp-1,100 mg/kg)、硒多糖低、中、高剂量组(Se-Msp1,剂量依次为50、100和200 mg/kg),灌胃体积0.1 mL/(10 g·bw),连续灌胃5周,检测大鼠体内血乳酸(blood lactic acid,BLA)、血尿素氮(blood urea nitrogen,BUN)、肝糖原(hepatic glycogen,HG)、肌糖原(muscle glycogen,MG)含量和骨骼肌线粒体中丙二醛(MDA)含量以及超氧化物歧化酶(superoxide dismutase,SOD)、过氧化氢酶(catalase,CAT)、谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)活性,评价Se-Msp1的抗运动疲劳作用。结果:羊肚菌多糖经分离纯化得到的最大组分为Msp-1,占比达到85.25%,红外光谱显示Se-Msp1的异头碳为α构型,且存在Se的特征吸收峰,表明Se-Msp1硒化成功,测得Se-Msp1硒含量为9.56 mg/g,多糖含量为56.34%,糖醛酸含量为36.82%,重均分子量3.482×10^(5) Da,粒径为384.71 nm,电位为-45.78 mV,说明Se-Msp1中硒含量较高且稳定性好,其由甘露糖、葡萄糖醛酸、半乳糖、半乳糖醛酸、半乳糖组成,摩尔比为1:0.42:3.57:3.34:1.86。抗疲劳结果显示,与空白对照组相比,Msp-1和Se-Msp1均极显著提高了大鼠力竭游泳时间(P<0.01),表现出较好的抗疲劳效果;运动疲劳模型结果显示,与运动疲劳对照组相比,Se-Msp1低、中、高剂量组大鼠HG和MG含量均极显著提高(P<0.01),BLA、BUN含量则极显著降低(P<0.01),骨骼肌线粒体中MDA含量同样极显著降低(P<0.01),抗氧化酶活性(SOD、CAT、GSH-Px)则极显著升高(P<0.01),且相比Msp-1,Se-Msp1具有更高的抗氧化活性。结论:制得的羊肚菌硒化多糖(Se-Msp1)结构稳定且具有较高的抗氧化和抗运动疲劳活性,为羊肚菌富硒多糖产品开发提供理论依据。

不同富硒方式对甘薯叶蛋白抗氧化活性的影响

以甘薯叶为研究对象,分别对叶面与土壤进行富硒处理,通过分析甘薯叶中硒含量及甘薯叶蛋白的抗氧化活性的变化,研究不同富硒方式对甘薯叶蛋白抗氧化活性的影响。结果显示叶面富硒与土壤富硒都能提高甘薯叶蛋白的硒含量,在1.6 mg/mL的富硒质量浓度条件下两种富硒处理组蛋白硒含量分别达到了20.10 mg/g与1.68 mg/g。富硒对甘薯叶蛋白的抗氧化活性有一定的提升作用,其中,叶面富硒可使甘薯叶蛋白超氧阴离子自由基清除率提升19.17%。根据相关性分析可知,除硒含量对抗氧化活性有较大影响外,样品中总酚与总黄酮含量也在一定程度上影响着样品的抗氧化活性。经对比可知,叶面富硒能更好地提高甘薯叶蛋白中的硒含量,是较佳的富硒方式。

酵母硒对肉仔鸡生长性能、屠宰性能及血清抗氧化指标的影响

文章旨在研究酵母硒对肉仔鸡生长性能、屠宰性能及血清抗氧化指标的影响。试验将1600羽1日龄的白羽肉鸡随机分为4组,每组8个重复,每个重复50羽。试验分1~21 d和22~42 d两阶段进行饲养,试验日粮分别添加0、0.1、0.2和0.4 mg/kg酵母硒。结果表明:1~21 d,与对照组相比,0.2 mg/kg的酵母硒组肉鸡末体重(FBW)显著提高5.59%,平均日增重(ADG)显著提高5.80%,料重比显著降低5.93%(P<0.05);22~42 d,与对照组相比,0.2 mg/kg酵母硒组肉鸡FBW显著提高4.25%,ADG显著提高3.62%(P<0.05);1~42 d,与对照组相比,0.2 mg/kg酵母硒组肉鸡ADG显著提高4.29%,料重比显著降低4.66%(P<0.05);此外,酵母硒对肉鸡全阶段ADFI均无显著影响(P>0.05)。0.2mg/kg酵母硒组肉鸡屠宰率显著提高(P<0.05);0.2mg/kg酵母硒组肉鸡胸肌率显著提高(P<0.05);0.2和0.4 mg/kg的酵母硒组肉鸡腿肌滴水损失显著降低(P<0.05);0.2 mg/kg酵母硒组肉鸡腿肌亮度显著降低(P<0.05)。21 d,0.2和0.4mg/kg酵母硒组肉鸡血清总超氧化物歧化酶(T-SOD)和总抗氧化能力(T-AOC)活性显著提高(P<0.05),丙二醛(MDA)含量显著降低(P<0.05),0.2 mg/kg酵母硒组肉鸡血清谷胱甘肽过氧化物酶(GSH-Px)活性显著提高(P<0.05);42 d,0.2和0.4mg/kg酵母硒组肉鸡血清谷胱甘肽过氧化物酶(GSH-Px)活性显著提高(P<0.05),0.2 mg/kg酵母硒组肉鸡血清丙二醛(MDA)含量显著降低(P<0.05)。综上所述,本试验发现,添加0.2 mg/kg的酵母硒可通过提升肉鸡血清抗氧化能力促进肉鸡生长发育。

硒对硼毒害下萝卜幼苗生理特性的影响

在明确不同浓度硒和硼对萝卜幼苗生长影响的基础上,进一步探索硒对硼毒害下萝卜幼苗生物量及活性氧代谢的影响,旨在为减轻萝卜幼苗硼毒害提供技术支撑。以‘雪单1号’萝卜为试验材料,采用盆栽试验,设置5个硒浓度(0、2.5、5、7.5、10μmol/L)和5个硼浓度(0、125、250、500、750μmol/L),研究叶面喷施不同浓度的硒和硼对萝卜幼苗生长的影响;在此基础上,选取2个硼处理(250、500μmol/L),通过叶面喷施清水和适量硒(5μmol/L),研究适量硒对硼毒害下萝卜幼苗生理特性的影响。结果表明,萝卜幼苗鲜重随叶面喷施硒和硼浓度的增加呈现先增加后降低的趋势,萝卜幼苗适宜的硒喷施浓度为5μmol/L、叶面喷施硼浓度为500μmol/L时,萝卜幼苗出现中毒症状;与正常施硼(250μmol/L)相比,硼毒害(500μmol/L)显著降低了萝卜幼苗干物质重,增加了硼含量和硼累积量,降低萝卜幼苗过氧化氢酶(CAT)、过氧化物酶(POD)、抗坏血酸过氧化物酶(APX)和谷胱甘肽(GSH)的含量,增加过氧化氢(H_(2)O_(2))和丙二醛(MDA)含量。叶面喷施适量硒(5μmol/L),与无硒处理相比,硼毒害处理萝卜幼苗硼含量、硼累积量分别降低40.06%、37.36%,幼苗POD、CAT、APX抗氧化酶活性分别增加14.82%、17.45%、18.05%,非酶抗氧化物GSH、抗坏血酸(ASA)含量分别增加13.89%、5.88%,H_(2)O_(2)、MDA含量分别降低28.43%、20.45%。适量硒可以提高萝卜幼苗抗氧化作用,降低活性氧累积,减轻过量硼对萝卜幼苗产生的毒害,扩大植株对硼的适应范围。

富硒对纳豆菌发酵鹰嘴豆产血管紧张素转化酶抑制肽的影响

该研究将富硒能力较强的纳豆芽孢杆菌作为发酵菌种,鹰嘴豆为原料,以血管紧张素转化酶(angiotensin I converting enzyme,ACE)抑制率为指标,采用单因素试验和响应面优化法对纳豆芽孢杆菌富硒后产ACE抑制肽的最佳条件进行优化。同时采用超高效液相色谱-电喷雾电离-串联质谱(ultra performance liquid chromatography electrospray ionization tandem mass spectrometry,UPLC-ESI-MS/MS)法对鹰嘴豆纳豆富硒后硒代氨基酸进行定性定量分析。结果表明,L-硒代胱氨酸是鹰嘴豆纳豆富硒后主要的硒代氨基酸,纳豆芽孢杆菌富硒后产ACE抑制肽的最佳条件为接种量2%、液料比18∶1(mL/g)、发酵温度40℃,ACE抑制率可达89.24%。对比试验的结果显示,纳豆芽孢杆菌不富硒发酵鹰嘴豆产ACE抑制肽活性为66.35%,表明富硒纳豆芽孢杆菌发酵鹰嘴豆对ACE活性有良好的抑制作用。

酵母硒复合制剂对蛋鸡生产性能及蛋品质的影响

为分析酵母硒复合制剂对蛋鸡生产性能及蛋品质的影响。试验选取300羽28周龄的海兰褐蛋鸡,随机分为4组,每组5个重复,每个重复15羽。对照组根据《海兰褐壳蛋鸡商品代饲养管理技术规程》(DB34/T1650~2012)配制基础日粮,试验组分别在基础日粮中添加100、200、300mg/kg酵母硒复合制剂。预饲期7d,正试期60d。结果表明:(1)1~30d阶段,随着基础日粮中酵母硒复合制剂添加水平的提高,产蛋率有增加趋势(P <0.10)。31~60d阶段,与对照组相比,基础日粮添加200、300mg/kg酵母硒复合制剂可显著提高蛋鸡的产蛋率、平均日产蛋重(P <0.05),且显著降低了蛋鸡的料蛋比(P <0.05)。(2)试验第30天,与对照组相比,基础日粮添加200、300mg/kg酵母硒复合制剂可显著提高蛋黄颜色(P <0.05)。试验第60天,与对照组相比,基础日粮添加200、300mg/kg酵母硒复合制剂可显著提高鸡蛋重量、蛋白高度(P <0.05),基础日粮添加100、200、300mg/kg酵母硒复合制剂可显著提高了蛋黄颜色(P <0.05)。由此可见,基础日粮中添加200、300mg/kg酵母硒复合制剂均能提高蛋鸡生产性能,有效改善蛋品质。

植物富硒肽的来源及生物活性的研究进展

硒(Se)是人体必需的微量营养素,在生命活动中发挥着重要的生理功能。与无机硒相比,有机硒生物利用度高且毒性低,是补充硒的优质来源。生物活性硒肽是有机硒的重要形式,主要来源于富硒植物提取和人工合成途径,由于具有多种有益健康的生物活性,生物活性硒肽已经成为近年来备受关注的研究热点。本文综合了国内外近几年的相关研究,概述了植物源生物活性硒肽的分离提取和人工螯合制备、常见的植物源生物活性硒肽及其在机体中的抗氧化、肝脏保护、免疫调节、抗癌、降血压等多种生物活性,以期为植物源生物活性硒肽在功能性食品和医药方面的开发利用提供理论参考。

日粮酵母硒添加水平对北京油鸡生产性能、蛋品质、蛋硒含量和抗氧化能力的影响

试验旨在研究日粮中添加不同水平酵母硒对北京油鸡生产性能、蛋品质、蛋硒沉积以及血清抗氧化能力的影响。选用同一批次、健康良好的北京油鸡504只,随机分为7组,每组6个重复,每个重复12只鸡。A组饲喂基础日粮(不额外添加硒源),B组~G组在基础日粮中额外添加0.1、0.2、0.3、0.4、0.5、0.6 mg/kg酵母硒(以硒计)。试验期63d,其中预试期7d,正式试验期56d。结果显示:酵母硒添加水平对北京油鸡生产性能影响不显著(P>0.05);E组~G组蛋黄色泽显著高于A组(P<0.05),但酵母硒添加水平对哈夫单位、蛋白高度、蛋形指数、蛋壳色泽、蛋壳强度、蛋壳厚度等指标影响不显著(P>0.05);日粮添加酵母硒能够提高蛋黄硒、蛋清硒和全蛋硒含量;随着酵母硒添加水平的提高,蛋鸡血清总抗氧化能力(T-AOC)显著提高(P<0.05),丙二醛(MDA)含量有降低的趋势(P>0.05),B组~G组血清谷胱甘肽过氧化物(GSH-Px)活性显著高于A组(P<0.05)。研究表明,添加不同水平的酵母硒对北京油鸡蛋鸡生产性无影响,有改善蛋黄色泽的趋势,可以增加蛋硒含量和血清抗氧化能力,推荐日粮酵母硒添加水平达到0.3mg/kg即可。

响应面法优化大鲵肽-硒螯合物制备工艺及其性质研究

为探究大鲵肽与硒的螯合能力,通过单因素试验、Plackett-Burman试验、最陡爬坡试验以及Box-Behnken试验优化了大鲵肽-硒螯合物的制备工艺,在此基础上对大鲵肽-硒螯合物结构特征和体外抗氧化活性进行评价。结果表明,大鲵肽质量分数7%、螯合时间60 min、体积比46∶100、p H 8.46、螯合温度65℃时,大鲵肽-硒螯合物得率最高为36.18%,与模型预测值34.54%无显著差异(P>0.05)。大鲵肽与Na_(2)Se O_(3)螯合后紫外光谱吸收峰强度增大且红移;傅里叶变换红外光谱上表征—COOH和酰胺官能团的振动谱峰发生了强度上和位置上的改变;α-螺旋和β-折叠含量显著上升(P<0.05),β-转角和无规则卷曲的含量显著减少(P<0.05)。大鲵肽-硒螯合物具有较强的羟自由基、超氧阴离子自由基清除能力及还原能力。该研究为大鲵肽高附加值产品开发提供一定参考。

不同种类含硒补充剂饲喂三黄鸡中硒和硒形态分布

通过分析三种不同剂量含硒补充剂饲喂的三黄鸡体内总硒及硒形态含量,研究硒在其体内的富集和分布情况,为发展富硒禽肉等功能农产品提供数据参考。采用微波消解-电感耦合等离子体质谱法(ICP-MS)测定经亚硒酸钠、富硒堇叶碎米荠和富硒酵母饲喂的三黄鸡组织中总硒含量;经55℃水浴超声辅助酶解提取,ZORBAX SB-Aq C18色谱柱分离,以10 mmol/L柠檬酸钠+5 mmol/L己烷磺酸钠(含1%甲醇,pH=4.0)为流动相,高效液相色谱与ICP-MS联用技术(HPLC-ICP/MS)测定其肌肉和肝脏中硒酸根[Se(Ⅵ)]、硒代半胱氨酸(SeCys)、甲基硒代半胱氨酸(MeSeCys)和硒代氨酸(SeMet)4种硒形态。分析结果显示,饲喂富硒酵母组的三黄鸡中肌肉和各组织器官中硒含量最高;鸡胸肉和鸡腿肉中主要硒形态为SeMet,肝脏主要硒形态为SeCys,饲喂富硒酵母组肌肉和肝脏中SeMet含量显著高于其他含硒补充剂组。研究结果表明,添加含硒补充剂的种类对三黄鸡组织中硒的富集有影响,饲喂富硒酵母能显著增加禽类组织中硒含量,特别是SeMet的含量,可为富硒禽肉的饲养提供参考。

嗜酸乳杆菌(Lactobacillus acidophilus)合成纳米硒特性研究

乳酸菌具有还原亚硒酸钠为纳米硒的能力。为了采用更加环境友好的方式获得纳米硒颗粒,本研究首先探索了培养基中加硒浓度、加硒时间,以及培养时长对嗜酸乳杆菌(Lactobacillus acidophilus)合成纳米硒的影响,随后对所产的纳米硒颗粒的粒径、zeta电位及抑菌活性进行研究。结果表明,当培养基中硒含量为0~600μg/mL时,硒浓度越高,转化得到的纳米硒越多;当培养基中硒浓度高于600μg/mL时,发酵液中的纳米硒含量反而减少。在嗜酸乳杆菌生长的对数中前期,即第6 h时添加亚硒酸钠,更有利于纳米硒的合成。而培养至32 h后,纳米硒几乎不再继续合成。通过扫描电镜及粒径和电位仪分析发现,嗜酸乳杆菌所产的纳米硒颗粒呈球形,且超声破碎有助于其释放;纳米硒颗粒带负电荷,电位绝对值为40~50 mV,粒径大小较多分布于170~210 nm,具有良好的稳定性。抑菌实验结果表明,嗜酸乳杆菌还原亚硒酸钠所产的纳米硒对大肠杆菌、沙门氏菌、金黄色葡萄球菌和枯草芽孢杆菌的生长均具有抑制作用。综上,嗜酸乳杆菌可以将亚硒酸钠还原合成纳米硒,且所产的纳米硒颗粒具有良好的抑菌活性。