研究: 奶牛与水牛初乳中乳寡糖组分比较研究

乳寡糖是由乳汁中含量丰富的固体物质组成．研究结果表明,乳寡糖有提高免疫、益生元及抗感染等作用,已发现与婴儿肠道发育、神经智力发育等多方面关系密切．水牛奶是除牛奶外的第二大奶源,国际上公认其为营养含量高、口感好的优质乳制品,但目前针对水牛乳寡糖的研究多以美洲水牛为研究对象,尚无中国水牛的相关研究．本研究利用固相萃取对已脱脂和除去蛋白质的广西水牛初乳乳汁样品进行纯化,并采用苯胺 (aniline,Bn)衍生化试剂对其进行衍生化处理,通过UPLC-ESI-Q-TOF-MS液相质谱进行优化后,对水牛初乳中的寡糖组分进行测定并与牛乳进行了对比,最终测得奶牛初乳中19种及水牛初乳中的9种乳寡糖组分,并对二者的种类及含量进行比较,发现在两种初乳的乳寡糖中,中性糖二糖m/z 385.15和中性糖三糖m/z 547.21以及酸性糖m/z 635.23均为其主要寡糖成分,与其他乳寡糖相比含量相对较高．总体而言水牛初乳中的中性寡糖占比比奶牛初乳高,二者中性糖占乳寡糖总量的比例分别为88.88%和63.16%．     

Studies on Immunoglobulins and Trypsin Inhibitor in Colostrum and Milk from Sows and in Serum of Their Piglets

The concentrations of IgG, IgM, IgA and the specific sow colostrum trypsin inhibitor (SCTI) were measured by radial immunodiffusion in colostrum and milk samples from sows and in serum samples from their offspring during the suckling period. A clear time dependence was found for all the measured variates in both whey and serum. Statistically significant positive correlations were found between, on the one hand, concentrations of IgG and IgA, but not IgM, in sera from 39 suckling piglets 1 and 3 days old, and, on the other hand, concentrations of the same immunoglobulins and of the trypsin inhibitor in maternal colostrum (n = 7). Multiple regression analyses showed that at day 1 and day 3 the levels of both IgG and IgA in serum samples from the suckling piglets were positively influenced by both the SCTI and the IgG or IgA contents in maternal colostrum.     

Isolation and Characterization of A Temperature Sensitive Protein from dog Colostrum And Milk

A temperature sensitive protein (one of several) that was soluble at 2°C but reversibly precipitated upon warming to room temperature was isolated from dog milk by precipitation with 50% saturated ammonium sulfate, ion exchange chromatography, centrifugation at 30°C and preparative isoelectric focusing in polyacrylamide gel. The molecular weight by sedimentation equilibrium was 13, 400; however, by thin layer gel filtration it appeared to be much larger. Ultracentrifu-gation studies at conditions near those at which the protein precipitated revealed no evidence of aggregation. The protein had a fairly high content of nonpolar amino acids with proline being in the highest amount. The effects of pH, ionic strength, heat and ethanol on the solubility of the protein were studied. A circular dichroism spectrum of the temperature sensitive protein indicated that the protein is quite unordered. An antiserum against the temperature sensitive protein reacted with each of the other temperature sensitive proteins from milk but not with dog serum or saliva.     

Evaluation of Potential Probiotics Isolated from Human Milk and Colostrum

Several studies have demonstrated a diversity of bacterial species in human milk, even in aseptically collected samples. The present study evaluated potential probiotic bacteria isolated from human milk and associated maternal variables. Milk samples were collected from 47 healthy women and cultured on selective and universal agar media under aerobic and anaerobic conditions. Bacterial isolates were counted and identified by Biotyper Matrix-Assisted Laser Desorption Ionization–Time of Flight mass spectrometry and then tested for probiotic properties. Total bacteria in human milk ranged from 1.5 to 4.0 log₁₀ CFU/mL. The higher bacterial counts were found in colostrum (mean = 3.9 log₁₀ CFU/mL, 95% CI 3.14–4.22, p = 0.00001). The most abundant species was Staphylococcus epidermidis (n = 76). The potential probiotic candidates were Lactobacillus gasseri (n = 4), Bifidobacterium breve (n = 1), and Streptococcus salivarius (n = 4). Despite the small sample size, L. gasseri was isolated only in breast milk from mothers classified into a normal weight range and after a vaginally delivered partum. No potential probiotics showed antagonism against pathogens, but all of them agglutinated different pathogens. Nine bacterial isolates belonging to the species L. gasseri, B. breve, and S. salivarius were selected as potential probiotics. The present study confirms the presence in breast milk of a bacterial microbiota that could be the source of potential probiotic candidates to be used in the formula of simulated maternal milk.     

Effects of Short-term Supplementation of Clinoptilolite in Colostrum and Milk on the Concentration of Some Serum Minerals in Neonatal Dairy Calves

In recent years, the use of both natural and synthetic zeolites in animal nutrition has increased mainly to improve their performance, health, and to protect against mycotoxin intoxication. Thirty calves were used in the present study for the determination of some physiologic effects of clinoptilolite supplementation. The animals were divided equally into three groups (control, test 1, and test 2). The three groups of calves were homogeneous for parity of dams, sex, and month of birth. For group test 1, clinoptilolite in the concentration of 2% of each colostrum meal was added for 48 h, and for group test 2, clinoptilolite in the concentration of 2% was added to each colostrum and milk meal for 14 days. Blood samples were taken from all calves 12 h after birth and at the end of the first, second, third, forth, fifth, and sixth weeks of life. Calcium (Ca), phosphorus (P), magnesium (Mg), iron (Fe), sodium (Na), and potassium (K) were determined in the serum. For statistical analysis of data, a repeated measures approach using analysis of variance (ANOVA) with mixed linear models was used. Clinoptilolite supplementation had significant effect on the concentrations of calcium, phosphorus, sodium, and iron. The concentrations of Fe significantly higher in test group 2 than other trial groups (p < 0.05). Calcium concentrations were significantly higher in serum of clinoptilolite-treated than control calves (p < 0.05). The concentrations of phosphorus were significantly lower in test groups than control group (p < 0.05). Sodium concentrations were significantly higher in clinoptilolite-supplemented groups than control calves (p < 0.05). Potassium and magnesium concentrations were not affected by clinoptilolite supplementation. Clinoptilolite supplementation could promote iron levels in serum and better hemopoiesis and prevent pathologic or physiologic drop of red blood cell (RBC) parameters in supplemented calves during a first few weeks of life. According to higher need and utilization of Ca in growing animals, clinoptilolite supplementation could increase available Ca. Based on the results of the present study and the importance of dietary phosphorus in many physiologic processes, the level of phosphorus in diet of neonatal dairy calves must be considered and adapted when clinoptilolite was supplemented. With an adequate supply of good quality drinking water, cattle can tolerate large quantities of dietary sodium chloride. Thus, it seems that significant increase in serum Na concentration during short-term supplementation of clinoptilolite in neonatal calves could be well tolerated without any adverse effects.     

Effect of Multi-Microbial Probiotic Formulation Bokashi on Pro- and Anti-Inflammatory Cytokines Profile in the Serum,Colostrum and Milk of Sows,and in a Culture of Polymorphonuclear Cells Isolated from Colostrum

Probiotics and Antimicrobial Proteins - The use of probiotics in sows during pregnancy and lactation and their impact on the quality of colostrum and milk, as well as the health conditions of their...     

Comparative Proteomics of Milk Fat Globule Membrane Proteins from Transgenic Cloned Cattle

The use of transgenic livestock is providing new methods for obtaining pharmaceutically useful proteins. However, the protein expression profiles of the transgenic animals, including expression of milk fat globule membrane (MFGM) proteins, have not been well characterized. In this study, we compared the MFGM protein expression profile of the colostrum and mature milk from three lines of transgenic cloned (TC) cattle, i.e., expressing recombinant human α-lactalbumin (TC-LA), lactoferrin (TC-LF) or lysozyme (TC-LZ) in the mammary gland, with those from cloned non-transgenic (C) and conventionally bred normal animals (N). We identified 1, 225 proteins in milk MFGM, 166 of which were specifically expressed only in the TC-LA group, 265 only in the TC-LF group, and 184 only in the TC-LZ group. There were 43 proteins expressed only in the transgenic cloned animals, but the concentrations of these proteins were below the detection limit of silver staining. Functional analysis also showed that the 43 proteins had no obvious influence on the bovine mammary gland. Quantitative comparison revealed that MFGM proteins were up- or down-regulated more than twofold in the TC and C groups compared to N group: 126 in colostrum and 77 in mature milk of the TC-LA group; 157 in colostrum and 222 in mature milk of the TC-LF group; 49 in colostrum and 98 in mature milk of the TC-LZ group; 98 in colostrum and 132 in mature milk in the C group. These up- and down-regulated proteins in the transgenic animals were not associated with a particular biological function or pathway, which appears that expression of certain exogenous proteins has no general deleterious effects on the cattle mammary gland.     

Comparative Studies of Brown Discoloration and Ammonia Liberation from the Milk Proteins by Ultraviolet Light Irradiation

Investigations were undertaken on α-, β-casein, β-lactoglobulin and α-lactalbumin isolated from fresh milk to ascertain the development of color and ammonia liberation when exposed to ultraviolet light.

Experimental data showed that α-, β-casein equally contributed to cause considerable brown discoloration, followed by α-lactalbumin, while β-lactoglobulin remained almost colorless. Furthermore, additional evidence in a model system suggested that the participation of tryptophan is very important in such a discoloration.

On the other hand, some discussion is offered together with the suggestion that the liberation of ammonia might initiate from histidine residue without hydrolysis of linkage of peptide in protein.     

黄鳝血清和体表粘液蛋白的比较研究

本文用反相高效液相色谱法测定了黄鳝血清和体表粘液蛋白的氨基酸种类和含量,比较了二者的氨基酸组成变化。结果表明：二者都含有17种氨基酸,血清的氨基酸总量为397．11mg／l00ml,体表粘液蛋白的氨基酸总量为259．29mg／l00m1,血清与粘液蛋白中氨基酸含量差异最大的是蛋氨酸、半胱氨酸。应用SDS—PAGE分析和比较了血清和体表粘液蛋白的分子量大小及特有区带效,黄鳝血清与体表粘液蛋白分子量相同的蛋白区带数为2条,其分子量大小分别为19．5kDa、96．0kDa。其中血清的特有蛋白带为18条,体表粘液的特有蛋白带为8条。此外,对二者的相关性和体表粘液特异性的免疫机制作了探讨。     

解偶联蛋白及功能研究进展

解偶联蛋白(ucP,uncoupling protein)是一类线粒体内膜上的载体,属于线粒体载体超家族,可以将H^ 从线粒体内膜渗漏到线粒体基质中,减少ATP的合成并产生热能。已知UCPl在小鼠中有维持体温和能量稳态的重要作用。而UCP2和UCP3可控制活性氧(reactive oxygen species,ROS)产生、调节脂肪酸氧化,并且在肥胖和糖尿病发生中有重要作用。     

Free Amino Acids and Phosphorylethanolamine in Milk Whey of Cow

Free amino acids in the milk of cow were investigated in comparison with those in the plasma. The concentrations of most free amino acids in the milk except for a few amino acid were lower than those in the plasma. It appears that the percentage of each amino acid in the milk against the corresponding amino acid in the plasma is the reflexion of casein synthesis in the mammary gland. Nutritional alteration influenced on the level of some amino acids in the milk. Free phosphorylserine, glycerylphosphorylethanolamine, and phosphorylethanolamine were observed in the milk. Phosphorylethanolamine was present in significantly high concentration in one animal as control, whereas was almost absent in another animal as experimental.