棉籽粕源发酵蛋白质饲料的代谢产物研究

本试验旨在通过液相色谱串联质谱(LC-MS)代谢组学分析平台对不同微生物棉籽粕源发酵蛋白质饲料代谢产物进行研究.采用LC-MS法对对照组、假丝酵母组、酿酒酵母组、复合组的发酵代谢产物进行分析,结合偏最小二乘法-判别分析(PLS-DA)方法对数据进行模式识别和小分子差异代谢产物寻找.结果表明:各试验组代谢产物相对含量与对照组相比差异显著(P＜0.05),且在PLS-DA分析中得到了很好的分离,主要表现在甘露醇、琥珀酸等糖类代谢产物;磷酸胆碱、L-肉碱、甘油磷酸、磷脂酰乙醇胺(PE)和磷脂酰胆碱(PC)等脂类代谢产物;二肽、三肽、甜菜醛、同型半胱氨酸等蛋白质与氨基酸的代谢产物;以及烟酸、阿魏酸、尿嘧啶、乙醇醛等其他途径代谢产物.除与脂类代谢有关的甘油磷酸、PE、PC相对含量显著降低之外(P＜0.05),其他试验组小分子代谢产物相对含量均比对照组显著增加(P＜0.05).由此可见,不同菌种发酵饲料中含有大量糖类、脂类、蛋白质等代谢途径产生的小分子代谢产物,含量因发酵菌种的不同而不同.     

基于LCMS技术对牦牛围产后期的血清动态代谢组学分析

旨在应用代谢组学的方法，阐明经产母牦牛围产后期动态代谢情况，探究营养代谢影响生殖激素的机制。本研究随机选取年龄（（7.13±0.78）岁）、体况（2.69±0.35）和胎次（（1.75±0.43）胎）相近的经产母牦牛8头作为试验动物，自分娩日开始每隔7 d收集血清至产后第28天，共5个时间点。应用液相质谱联用技术对5个时间点的血清样本进行检测，并通过生物信息学分析筛选关键代谢物，构建经产母牦牛围产后期动态代谢网络机制。试验在正、负离子模式下分别获得2 841和1 326种代谢物定性分析的结果，通过计算各时间点代谢物表达量的差异倍数、VIP值及每两个时间点T-test检验的P值，共筛选出117种差异代谢物。根据生物信息学分析，分别获得与繁殖性能、脂类代谢和氨基酸代谢相关的3种、7种和8种关键代谢物。基于关键代谢物构建动态代谢网络机制发现，糖代谢在围产后期的起始阶段作用效率较低，末期升高，脂类和氨基酸代谢在起始阶段作用效率较高，末期降低，推测经产母牦牛在产后发生能量负平衡。生殖激素的合成和分泌作用效率在围产后期一直维持较低水平。根据对经产母牦牛动态代谢谱的检测和网络机制的构建发现，经产母牦牛产后发生了能量负平衡，由于过度脂肪动员导致雌激素的合成和分泌受阻，这可能是导致经产母牦牛产后生殖机能不能及时恢复的主要原因，但具体机制还需要进一步验证。     

Normal ranges and temporal variation in plasma concentrations of L-lactate and free amino acids in adult sheep

To determine baseline variation in blood plasma concentrations of free amino acids and l-lactate, samples were collected at a single time point from nine flocks of different breeds of ewes at a common physiological stage and monthly from one flock of crossbred mule ewes over a 12 month period. Significant differences were detected between time points in the concentrations of all plasma metabolites. With few exceptions prion protein genotype had no significant effect on the plasma metabolite concentrations measured.     

不同精粗饲料对泌乳中期山羊氨基酸的代谢流向及乳蛋白含量的影响

 通过检测泌乳中期山羊血浆及乳中游离氨基酸含量的变化,探讨不同精粗比饲料对机体中氨基酸（ａｍｉｎｏａｃｉｄｓ,ＡＡ）的代谢流向及乳蛋白的影响。选用泌乳中期山羊７只,随机分为２组,分别饲喂精粗比４∶６（低精料组）和６∶４（高精料组）日粮,颈静脉血管瘘采血,手工挤奶取奶样。Ｂｒａｄｆｏｒｄ法测定乳中总蛋白质浓度,ＲＰ－ＨＰＬＣ检测山羊血浆和乳中游离氨基酸的含量。结果表明,２组山羊血浆中均分离出１４种游离氨基酸,乳中分离出８种游离氨基酸,不同精粗比饲料对血液或乳中游离氨基酸谱无明显影响。不同精粗比日粮情况下,除丙氨酸外,血液中游离氨基酸的含量均高于乳中同种氨基酸的含量;且血液中生酮氨基酸（Ｌｅｕ,Ｌｙｓ）、兼性氨基酸（Ｐｈｅ,Ｉｌｅ）和支链氨基酸（Ｌｅｕ,Ｉｌｅ和Ｖａｌ）含量显著或极显著高于乳中。高精料组除Ｇｌｙ和Ａｌａ外,其余氨基酸含量均低于低精料组;乳中总蛋白浓度略高于低精料组,但无统计学差异。表明血液中游离氨基酸为乳蛋白的合成提供了原料和能量保证。饲喂高精料日粮,血液中游离氨基酸含量较低,不利于乳蛋白含量和产量的提高。     

牛初乳与牛常乳中游离氨基酸和不溶性蛋白质氨基酸对比研究

牛乳是生产婴幼儿配方乳粉时首要选择的原料乳,氨基酸是构成牛乳蛋白质的结构单位,按照分布区域的不同,分为游离氨基酸和不溶性蛋白质氨基酸两类。以产后0～7 d的牛初乳和15 d～6 个月的牛常乳为原料,对牛乳中不同结构域的氨基酸种类及含量进行对比分析。结果表明：9 种游离必需氨基酸在牛初乳和牛常乳中均被检测到,分别有8 种和7 种游离非必需氨基酸在牛初乳和牛常乳中被检测到,其中,牛初乳中8 种必需氨基酸、4 种非必需氨基酸含量均显著高于牛常乳（P＜0.05）;在不溶性蛋白质氨基酸中,牛初乳和牛常乳中均含有8 种必需氨基酸和10 种非必需氨基酸,其中,牛初乳中苏氨酸、精氨酸、丝氨酸、半胱氨酸、丙氨酸含量显著高于牛常乳（P＜0.05）,而牛常乳中赖氨酸含量显著高于牛初乳（P＜0.05）。     

三个柠檬品种果实非可食部分初生代谢产物分析

为了比较贵州产尤力克柠檬、四季柠檬和阿特摩柠檬果实非可食部分初生代谢产物差异,本研究采用GC-MS分析了3个柠檬成熟果实非可食部分氨基酸、有机酸和糖等初生代谢产物含量。结果表明,共检测到29个初生代谢产物,其中氨基酸8个、有机酸11个、糖10个,不同柑橘品种不同组织氨基酸、有机酸、糖等初生代谢产物种类和含量存在较大的差异。3个品种均是脯氨酸含量最高;3个品种有机酸种类相似,黄皮层和白皮层含量最高的为奎宁酸,而囊衣含量最高的为柠檬酸。对检测的糖类而言,均是葡萄糖含量最高。     

鸡胚发育过程中胚胎液中几种游离氨基酸的动态变化

本实验旨在研究鸡胚发育过程中尿囊液和羊水中天冬氨酸、谷氨酸、精氨酸和亮氨酸浓度的动态变化。选用72枚6胚龄的三黄鸡鸡胚,按重量相近原则分为6组,每组12个重复,分别在孵化第7、8、11、13、14、18天采集尿囊液和羊水,并利用高效液相色谱法分析其氨基酸浓度。结果表明:尿囊液中,除8胚龄外,其他各胚龄精氨酸浓度均高于另外3种氨基酸(P<0.05),13胚龄精氨酸浓度显著低于其他胚龄(P<0.05),而18胚龄显则著高于其他胚龄(P<0.05)。羊水中,各胚龄精氨酸浓度均高于其他3种氨基酸;除11胚龄外,13胚龄精氨酸浓度显著高于其他胚龄(P<0.05);7胚龄天门冬氨酸浓度显著高于13、14、18胚龄(P<0.05);但18胚龄谷氨酸及亮氨酸浓度则显著升高(P<0.05)。以上结果说明,在尿囊液及羊水中,所测4种氨基酸浓度变化不尽相同,但总体精氨酸含量最丰富,这可能与鸡胚发育的营养与代谢有关。     

Cloning, expression and characterization of monkey (Macaca fascicularis) CD137

CD137 plays an important role as a co-stimulatory molecule in activated T cells. Agonistic CD137 specific antibodies have been investigated as therapeutic agents to promote tumor-specific immune responses by direct activation of T cells. As part of the pre-clinical pharmacological evaluation of cynomolgus monkeys, monkey CD137 was cloned and characterized. The deduced amino acid sequence encoded a full-length gene of 254 amino acids 95% identical to human CD137. Sequence variants identified in monkey CD137 include four splice variants lacking the transmembrane domain. These variants were detectable in human including two previously unreported variants. Two missense single nucleotide polymorphisms were detected present in 42 and 50% of 36 monkeys tested. In both monkey and human, mRNA expression of full-length CD137 and splice variants were significantly increased in peripheral blood mononuclear cells (PBMCs) upon stimulation by anti-CD3 antibodies. Recombinant monkey CD137 protein was bound with high affinity by an agonistic anti-human CD137 antibody but not by an anti-mouse CD137 antibody. In summary, compared to human, monkey CD137 showed distinct extracellular domain amino acid sequence and sequence polymorphisms. Thus, antibodies directed against epitopes in this extracellular domain could have differences in pharmacologic activity between cynomolgus monkeys and human or across individual cynomolgus monkeys.     

Effect of hemodialysis on plasma amino acid concentrations in healthy dogs

OBJECTIVE: To characterize the effect of maintenance hemodialysis on plasma amino acid concentrations and to quantitate free amino acid losses into the dialysate during hemodialysis in healthy dogs. ANIMALS: 8 healthy adult dogs. PROCEDURE: Five dogs received hemodialysis treatments 3 times per week for 4 weeks. Plasma amino acid concentrations were evaluated once per week for 4 weeks in each of the 5 dogs prior to hemodialysis (time 0), 90 minutes during hemodialysis, and immediately after hemodialysis (180 minutes). Total free amino acid concentrations and plasma amino acid concentrations (time 0, 90 minutes, and 180 minutes) in the dialysate were evaluated in 3 dogs that received 1 hemodialysis treatment. RESULTS: Significant time versus week interactions with any plasma amino acid were not detected; however, significant decreases in all plasma amino acid concentrations measured were detected at the midpoint of dialysis (46 +/- 2%) and at the end of each dialysis session (38 +/- 2%). Mean (+/- SEM) total free amino acid loss into the dialysate was 2.7 +/- 0.2 g or 0.12 g/kg of body weight. CONCLUSIONS AND CLINICAL RELEVANCE: Hemodialysis is associated with significant alterations in plasma amino acid concentrations and loss of free amino acids into the dialysate. Loss of amino acids into the dialysate, coupled with protein calorie malnutrition in uremic patients, may contribute to depletion of amino acid stores.     

高精料对泌乳期山羊肝脏氨基酸分配与重分配及乳蛋白的影响

为了探讨饲喂不同精粗比日粮对肝脏氨基酸分配与重分配的影响及可能的机制,本研究选择6只安装了肝脏多血管瘘的健康泌乳奶山羊,分别饲喂精粗比为40∶60(对照组)和60∶40(高精料组)的饲料,2×2拉丁方设计,饲喂期16周。期间取乳样,测定乳蛋白含量,并通过肝门静脉、肝静脉和股动脉血管瘘取血, RP-HPLC法测定血浆中游离氨基酸含量。结果表明,高精料组山羊乳中乳蛋白含量显著低于低精料组(P<0.05);肝门静脉血液中各游离氨基酸含量均高于低精料组,而肝静脉和股动脉血液中各游离氨基酸含量均低于低精料组,即高精料组各游离氨基酸在肝脏中的消耗量均多于低精料组,通过股动脉进入乳腺组织的氨基酸含量也少于低精料组。本研究结果显示,长期饲喂高精料日粮,乳蛋白含量降低。其机制与肝脏中氨基酸分配与重分配发生改变,氨基酸在肝脏中消耗量增大,进入乳腺组织合成乳蛋白的前体物氨基酸减少有关。     

科尔沁沙地播种时期对不同紫花苜蓿品种抗寒性的影响

为探讨科尔沁沙地苜蓿根颈抗寒保护物质对播种时期的生理响应。选择3个紫花苜蓿品种(骑士T、公农1号、擎天柱),在内蒙古自治区赤峰市阿鲁科尔沁旗草业核心区,于2017年7月1日开始,每隔5 d播种一期,播种至8月15日。2017年10月11日、11月11日取样测定紫花苜蓿根颈中可溶性糖、可溶性蛋白、游离氨基酸、淀粉含量,翌年春季调查越冬率,对苜蓿根颈中的抗寒保护物质含量变化及其与越冬率的相关性进行探究。结果表明,随着播种时期的推迟,苜蓿根颈的可溶性糖、可溶性蛋白、淀粉、游离氨基酸均呈递减趋势,苜蓿越冬率与11月11日取样测定苜蓿根颈中的可溶性糖、可溶性蛋白、游离氨基酸均呈极显著正相关关系;苜蓿越冬率与10月11日取样测定苜蓿根颈中的可溶性糖含量呈显著正相关关系,与可溶性蛋白和游离氨基酸呈极显著正相关关系;公农1号苜蓿品种在11月11日测定的根颈的可溶性糖含量及淀粉含量显著高于骑士T和擎天柱,且与越冬率变化一致。研究认为,播种时期是影响科尔沁沙地苜蓿越冬的重要因素之一,苜蓿根颈中可溶性糖、可溶性蛋白、游离氨基酸是抗寒保护物质。为确保安全越冬科尔沁沙地种植苜蓿最佳的播种时期为7月1日-7月16日,适宜该地区种植的品种为公农1号。     

不同品系高羊茅应答高温胁迫的初级代谢产物分析

为探讨高温对高羊茅初级代谢的影响,对耐热性不同的两个高羊茅基因型PI 578718(耐热)和PI 234881(热敏感),进行40℃/35℃(昼/夜各12 h)模拟高温胁迫21 d,分别于不同时间段取样测定生理以及代谢产物的变化。结果表明,在高温胁迫下,草坪质量、叶绿素含量、叶片相对含水量、根系活力持续下降,电解质渗漏加剧,与耐热型基因型相比,热敏感基因型各生理指标变化更明显。通过GC-MS分析,检测并鉴定了25种初级代谢产物,主要包括有机酸和脂肪酸(9种)、氨基酸(9种)、糖类和糖醇(7种),其中氨基酸(如脯氨酸、缬氨酸、谷氨酸)、糖类(如蔗糖)和糖醇(如肌醇)在叶片中大量积累,而有机酸和脂肪酸类(如柠檬酸、棕榈酸)在根系中大量积累。高温胁迫下叶片和根系中代谢产物如缬氨酸、谷氨酸、脯氨酸、蔗糖、肌醇、柠檬酸、棕榈酸含量的升高或维持,可能是耐热基因型PI 578718与热敏感基因型PI 234881之间耐热性差异的主要原因,而且柠檬酸作为抗氧化剂并参与呼吸作用的三羧酸循环途径,它的高积累,可能更有助于提高高羊茅对高温胁迫的耐性和适应性。     

冻(冰鲜)牛肉贸易风险预警特征及出口安全控制

为揭示全球主要贸易国家/地区冷冻(冰鲜)牛肉的进出口风险特征,确定牛肉生产链(肉牛养殖—屠宰加工—出口)全过程安全风险关键控制环节,对2012年9月—2020年11月全球主要贸易国家(地区)210例/217种次冻(冰鲜)牛肉安全风险预警案例进行统计分析,同时采集重庆市出口牛肉加工备案企业的牛肉样品以及备案牛场的肉牛、饮...     

Non‐targeted analyses of animal plasma: betaine and choline represent the nutritional and metabolic status

Simple liquid chromatography–mass spectrometry (LC‐MS) was applied to non‐targeted metabolic analyses to discover new metabolic markers in animal plasma. Principle component analysis (PCA) and partial least squares–discriminate analysis (PLS‐DA) were used to analyse LC‐MS multivariate data. PCA clearly generated two separate clusters for artificially induced diabetic mice and healthy control mice. PLS‐DA of time‐course changes in plasma metabolites of chicks after feeding generated three clusters (pre‐ and immediately after feeding, 0.5–3 h after feeding and 4 h after feeding). Two separate clusters were also generated for plasma metabolites of pregnant Angus heifers with differing live‐weight change profiles (gaining or losing). The accompanying PLS‐DA loading plot detailed the metabolites that contribute the most to the cluster separation. In each case, the same highly hydrophilic metabolite was strongly correlated to the group separation. The metabolite was identified as betaine by LC‐MS/MS. This result indicates that betaine and its metabolic precursor, choline, may be useful biomarkers to evaluate the nutritional and metabolic status of animals.     

农业执法案件中未知粉末的分析研究

对农业执法案件中缴获的未知粉末进行分析研究。应用超高效液相色谱-飞行时间高分辨质谱（UPLC-TOF-HRMS）获得未知物分子离子峰的精确质量数、天然同位素信息，二级特征碎片的精确质荷比，并应用SCIEX PeakView及MasterView软件进行分析。经过靶向及非靶向筛查，同时参考文献报道，推导出未知粉末中的疑似化合物。采用高效液相色谱-二极管阵列检测器（HPLC-PDA）法及UPLC-TOF-HRMS法进行了双重确证。结果显示该未知粉末中含克仑特罗（16 g?kg-1）及其合成前体克仑特罗杂质B（455 g?kg-1）。本文详述的分析技术可为未知添加物的筛查和确证提供思路和技术参考。     

Correlation between skeletal muscle fiber type and free amino acid levels in Japanese Black steers

Free amino acids are important components of tastants and flavor precursors in meat. To clarify the correlation between muscle fiber type and free amino acids, we determined the concentrations of various free amino acids and dipeptides in samples of different muscle tissues (n = 21), collected from 26‐month‐old Japanese Black steers (n = 3) at 2 days postmortem. The proportions of the myosin heavy chain (MyHC), slow (MyHC1) and fast (MyHC2) isoforms were determined by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE). The contents of free amino acids and dipeptides were measured by high performance liquid chromatography (HPLC). The MyHC isoform composition varied among the tissue samples. The MyHC1 proportion ranged from 6.9% ± 3.9% to 83.3% ± 16.7%. We confirmed that there was a strong positive correlation between MyHC1 composition and total free amino acid concentrations, including those for two dipeptides. Among the 31 measured free amino acids and dipeptides, 11 showed significant positive correlations and five showed significant negative correlations with MyHC1 composition. These results suggest that a high MyHC1 content induces high free amino acid contents in bovine muscles possibly because of greater oxidative metabolism. This high level of free amino acids could contribute to the intense flavor of meat that is rich in slow‐twitch fibers.     

家蚕雌蛾体中氨基酸的分析

分析了家蚕雌蛾体中氨基酸组成与含量,并对其进行了质量评价。家蚕雌蛾体富含氨基酸,检测到了17种水解氨基酸和15种游离氨基酸。水解氨基酸和游离氨基酸的总含量分别为53．37％和3．637％,其中人体必需氨基酸含量分别为20．36％和0．798％,占氨基酸总量的比值分别为38．15％和21．94％,接近或超过WHO推荐模式。研究结果显示,家蚕雌蛾是开发食品和药品的优质原料。     

Regulation of taste-active components of meat by dietary branched-chain amino acids; effects of branched-chain amino acid antagonism

1. The effects of dietary branched-chain amino acids (BCAAs) including leucine (Leu), isoleucine (Ile) and valine (Val) on taste-active components, especially free glutamate (Glu), in meat were investigated. 2. Broiler chickens (28 d old) were given varied dietary BCAA levels for 10 d before marketing. Dietary BCAA content ratios were either 100:100:100 (Low Leu group), 150:100:100 (Control group) or 150:150:150 (High Ile + Val group) for Leu:Ile:Val (% of each BCAA requirement according to NRC, 1994). Taste-related components of meat (free amino acids and ATP metabolites) and sensory scores of meat soup were estimated. 3. Free Glu content, the main taste-active component of meat, was significantly increased by dietary BCAA. Compared to the Control group, free Glu content increased by 30% in the High Ile + Val group. However, the inosine monophosphate (IMP) content in meat did not change among groups. 4. Sensory evaluation of meat soups showed that Control and High Ile + Val groups had different meat flavours. The sensory score of overall taste intensity was significantly higher in the High Ile + Val group. 5. These results suggest that dietary BCAA concentrations regulate free Glu in meat. Increasing dietary Ile + Val induces an increase in free Glu content of meat, improves meat taste and is more effective for increasing free Glu content in meat than decreasing dietary Leu level.     

花粉的生物化学与营养保健

作者对花粉的生化成分 :糖类、脂类、蛋白质与氨基酸、核酸、酶类的组成、含量进行了较详实的论述 ,并对其在人体内的营养保健、新陈代谢等生命活动过程中的作用机理作了较深入的阐述 ,可为花粉的进一步研究、开发与创新提供理论依据     

Amino acid concentrations in blood serum of horses performing long lasting low-intensity exercise

The aim of this work was to evaluate the changes in the concentrations, after two rides different for distance covered, of different amino acids in endurance horses. Blood samples have been collected from horses just before the start, at the top of a steep slope (819 m difference in height) and just at the end of a 32-km endurance ride. A second group, competing in a 72 km endurance ride, has also been sampled immediately before and after the race. In serum samples, the concentrations of alanine, arginine, asparagine, glycine, isoleucine, histidine, leucine, lysine, methionine, ornithine, phenylalanine, tryptophan, tyrosine and valine have been measured by high-performance liquid chromatography (HPLC). anova and t-test have been used to study the differences in the concentrations of the amino acids. The pre-ride concentrations of the free amino acids were different between the two races, except for methionine and leucine. Differences between start and end race have been found for both groups for all the considered parameters except asparagine, isoleucine, leucine and lysine for the 72 km ride. Increases have been recorded for the shorter and decreases for the longer ride in the blood serum concentrations. Significant increases have also been found between the starting sampling and the second, at the top of the slope, only for alanine, arginine, asparagines, phenylalanine and lysine. The ride length has a significant impact on blood serum amino acids mobilization and uptake; in the shorter race the increases stand only for mobilization, whereas in the longer the decrease can be considered the effect of the onset of the amino acids catabolism.