Chemical analysis and photoprotective effect of an extract of wine from Jacquez grapes

The present study was aimed at evaluating the in vitro antioxidant activity and in vivo photoprotective activity of an extract of wine obtained from Jacquez (Vitis aestivalis‐cinerea × V vinifera) grapes (JW‐E). The chemical profile of the JW‐E was characterised by a significant level of proanthocyanidins, together with lower amounts of anthocyanins and hydroxycinnamic acids. The antioxidant activity of the JW‐E was assessed by means of various in vitro tests (bleaching of the stable 1,1‐diphenyl‐2‐picrylhydrazyl radical; peroxidation, induced by the water‐soluble radical initiator 2,2′‐azobis(2‐amidinopropane) hydrochloride, on mixed dipalmitoylphosphatidylcholine/linoleic acid unilamellar vesicles; UV radiation‐induced peroxidation in phosphatidylcholine multilamellar vesicles). In all in vitro tests employed, the JW‐E proved to possess strong antioxidant/free radical‐scavenging effectiveness. Furthermore, when topically applied, a gel formulation containing the JW‐E afforded significant in vivo protection against UVB light‐induced skin erythema (monitored by reflectance spectrophotometry) in healthy human volunteers. © 2002 Society of Chemical Industry     

Wood shrinkage: influence of anatomy, cell wall architecture, chemical composition and cambial age

The influence of microfibril angle (MfA), density and chemical cell wall composition on shrinkage varied between the longitudinal and tangential directions as well as between wood types, namely compression wood (CW), mature wood (MW) and juvenile wood (JW). At the same MfA, CW exhibited a lower tangential shrinkage than JW, indicating the influence of the chemical composition on wood shrinkage. The chemical composition measured via FTIR micro-spectroscopy has been shown in conjunction with density to be an alternative to MfA data for shrinkage predictions. This was particularly true for wood of young cambial age for which the MfA did not correlate to shrinkage. The results indicate a possibility to reduce distortion of sawn timber by segregation using infrared (IR) and X-ray in-line measurements.     

靖州杨梅果酒发酵菌种筛选、鉴定及发酵性能研究

以不同杨梅园杨梅鲜果、杨梅叶和果园土壤为原料,共分离得到172株酵母菌。采用显色法、杜氏管法、糖发酵法和杨梅酒发酵法进行四级筛选,获得3株综合性能优良的菌株;经形态学、分子生物学鉴定为酿酒酵母(Saccharomyces cerevisiae)RY1、仙人掌有孢汉逊酵母(Hanseniaspora opuntiae)DY5与有孢汉逊酵母(Hanseniaspora pseudoquilliermondii)JW14。通过发酵性能研究发现,3株酵母均能耐受可溶性固形物含量(SSC)为32%、SO_2添加量为200mg/L、酒精含量为16%Vol、pH为2.0的环境;RY1酵母具有较强的发酵性能及耐受能力,适宜发酵杨梅果酒,DY5和JW14酵母具有较好的产香能力,适宜辅助发酵为杨梅酒增香。     

假单胞菌JW12脂肪酶的补料分批发酵

研究了假单胞菌ＪＷ１２脂肪酶在２Ｌ和２５Ｌ容积发酵罐的补料分批发酵工艺．通过调整碳源补加速率,控制产酶期发酵液ＰＨ在８．２左右,能有效提高脂肪酶的酶活和表观生产率．在２５Ｌ标准发酵罐中,连续补加吐温－８０,最高脂肪酶酶活为１２９．２μｍｏｌ／（ｍｉｎ·ｍＬ）,表观生产率为１５．９１     

酸性蛋白酶高产菌株选育

以黑曲霉ＪＷ３０３９为出发菌株，通过ＥＭＳ多次诱变处理及最适培养和发酵条件的摸索，使其酸性蛋白酶产量从１８００～２０００ｕ／ｍｌ提高到３３００ｕ／ｍｌ。     

Study on distribution pattern of stable carbon isotope ratio of Chinese honeys by isotope ratio mass spectrometry

The δ ¹³C values of 26 varieties of Chinese pure single‐flower honeys, 323 census samples of six varieties of single‐flower honeys and one multi‐flower honey as well as 20 888 commercial honey samples from 135 honey‐related enterprises in 25 provinces of China were analysed by stable carbon isotope ratio mass spectrometry between 1998 and 2004. It was found that the δ ¹³C values of different Chinese honeys fell within the ranges of values proposed by JW White. This shows that White's theory of the stable carbon isotope ratio of honeys is applicable to Chinese honeys and further demonstrates that the theory is universal to honeys from all over the world. The study also confirmed that the δ ¹³C values of honeys do not bear much relation to the environment in which the honey plants are grown, e.g. geographical area, water and soil, climate, etc., but do vary slightly with the honey plant species. Copyright © 2005 Society of Chemical Industry     

Antagonism of Helicobacter pylori by bacteriocins of lactic acid bacteria

Antimicrobial activity of seven bacteriocins produced by lactic acid bacteria against Helicobacter pylori strains (ATCC 43504, Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH [DSM] 4867, DSM 9691, and DSM 10242) was investigated in vitro using a broth microdilution assay. The bacteriocins chosen for the study were nisin A; lacticins A164, BH5, JW3, and NK24; pediocin PO2; and leucocin K. Antimicrobial activity of the bacteriocins varied among the H. pylori strains tested, of which strain ATCC 43504 was the most tolerant. Among the bacteriocins tested, lacticins A164 and BH5 produced by Lactococcus lactis subsp. lactis A164 and L. lactis BH5, respectively, showed the strongest antibacterial activity against H. pylori strains. MICs of the lacticins against H. pylori strains, when assessed by the critical dilution micromethod, ranged from 0.097 to 0.390 mg/liter (DSM strains) or from 12.5 to 25 mg/liter (ATCC 43504), supporting the strain-dependent sensitivity of the pathogen. Pediocin PO2 was less active than the lacticins against four strains of H. pylori, and leucocin K was the least active peptide, with no inhibition toward H. pylori ATCC 43504. Anti-Helicobacter activity of lacticin A164 was dependent on initial inoculum size as well as concentration of the bacteriocin added.     

油酸乙氧基化物与硬脂酸乙氧基化物的合成与性能

以油酸和硬脂酸为原料,与环氧乙烷(EO)反应得到平均EO加合数为15的油酸乙氧基化物(OAE-15)和硬脂酸乙氧基化物(SAE-15)。通过FT-IR以及化学方法确定了生成物的结构。对OAE-15和SAE-15的物化性能和应用性能进行了测试并进行了对比,结果表明:SAE-15的去污性能优于OAE-15,降低表面张力的能力和效率都高于OAE-15,二者泡沫性能相当;OAE-15的润湿性能和乳化性能都优于SAE-15。     

HS-SPME-GC-MS分析高产酯低产高级醇酿酒酵母发酵酒的风味物质

采用顶空固相微萃取-气相色谱质谱联用(HS-SPME-GC-MS),分析添加不同高产酯低产高级醇酿酒酵母发酵得到酒样中的挥发性成分,并采用气相色谱对其中的主要风味物质进行定量分析。气相色谱质谱联用在酿酒酵母AY15、AY15-BAT2、AY15-BAT2+ATF1、AY15-IAH1+ATF1的酒样中分别分离鉴定出62、56、63、59种挥发性成分,主要包括酯类、醇类、醛类、酸类、烷烃、芳香烃和酚类等。三株具有不同高级醇和酯生成能力的酿酒酵母发酵得到的酒样中酯类与高级醇的比例相比野生菌株AY15均有不同程度的提高,其中,AY15-BAT2+ATF1酒样中新检出乙酸正丁酯、乙酸庚酯、乙酸辛酯、乙酸苯乙酯、乙酸-甲氧基-2-苯乙酯五种乙酸酯。定量结果表明,AY15-BAT2+ATF1与AY15-IAH1+ATF1显著提高了乙酸乙酯和乙酸异戊酯的含量,AY15-BAT2则不影响主要酯类物质的生成;同时,这三株酿酒酵母不同程度的降低了酒中正丙醇、异丁醇和异戊醇的含量。     

微生物发酵合成15N-L-脯氨酸

采用含有稳定同位素15N 氯化铵为主要氮源的专用发酵培养基配方和相应的提取精制条件,采用微生物直接发酵方法研制15N L 脯氨酸高丰度产品.结果显示,每克15N 氯化铵实际可得0.376g15N L 脯氨酸,提取精制得率最高达65.76%,产品15N丰度达98.28%,比原料下降1.23%.     

Up-regulation of expression of interferon-stimulated gene 15 in the bovine corpus luteum during early pregnancy

Interferon-τ (IFNT), the pregnancy recognition signal in ruminant species, is secreted by conceptus trophectoderm cells and induces expression of IFN-stimulated gene 15 (ISG15) in the uterus and corpus luteum (CL) in ewes. Expression of ISG15 in ovine CL is speculated to be through an endocrine pathway, but it is unclear whether expression of ISG15 in bovine CL is via such a pathway. In this study, CL were obtained from cows on d 16, 25, 60, 120, 180, and 270 of pregnancy, and endometrium, mammary gland, ovarian stroma, and CL were also collected from cows on d 18 of pregnancy and on d 15 and 18 of the estrous cycle. All tissue explants from d 15 of the estrous cycle were cultured in the absence or presence of 100 ng/mL of recombinant bovine IFNT for 24 h. The results indicated that ISG15 and conjugated proteins were expressed in CL of both cyclic and pregnant cows regardless of pregnancy status and were upregulated during early pregnancy. The mammary gland from d 18 of pregnancy did not express ISG15, but explants of the mammary gland from d 15 of the estrous cycle did express ISG15 after being treated with IFNT. However, luteal explants from d 15 of the estrous cycle did not express ISG15 after being cultured for 24 h. In conclusion, ISG15 expression is upregulated in the bovine CL during early pregnancy. Interestingly, cultured CL cells do not respond to IFNT, suggesting that the pregnancy-dependent stimulation of ISG15 expression is controlled by something other than IFNT in the bloodstream.     

Nitrogen utilization, nutrient digestibility, and excretion of purine derivatives in dairy cattle consuming rations containing corn milling co-products

The objectives of this experiment were to determine the effects of feeding a combination of modified wet distillers grains with solubles (WDGS) and wet corn gluten feed (WCGF) on nutrient digestion, purine derivative excretion, and N utilization. Multiparous (n = 20) and primiparous (n = 20) cows were arranged in a replicated 5 × 5 Latin square with 21-d periods. Animals were fed one of 5 treatment diets during each period: 1) 0% co-products (control); 2) 15% WDGS (15WDGS); 3) 15% WCGF (15WCGF); 4) 7.5% WDGS and 7.5% WCGF (15MIX); and 5) 15% WDGS and 15% WCGF (30MIX; dry matter basis). A portion of forages, corn, and soy-based protein was replaced with WDGS, or WCGF, or both. Dry matter intake was greater for 15WDGS (25.1 kg/d) and 30MIX (25.5 kg/d) than for control (22.4 kg/d), 15WCGF (23.2 kg/d), or 15MIX (23.5 kg/d). Dry matter digestibility was greatest for 15WCGF and 30MIX (63.6 and 64.1%, respectively) and least for 15WDGS (59.8%), and neutral detergent fiber and N digestibility were greatest for 30MIX (50.7 and 68.6%, respectively) and lowest for 15WDGS (41.3 and 61.5%, respectively). Excretion of purine derivatives in urine was greater for co-product treatment diets than for control. Fecal N was greatest for 15WDGS compared with other treatment diets (311.0 vs. 263.3 g/d), whereas urinary N was greatest for 30MIX (330.0 g/d), intermediate for 15WCGF and 15MIX (319.3 and 320.5 g/d, respectively), and lowest for control and 15WDGS (308.5 and 312.2 g/d, respectively). Manure N (fecal + urinary N) was greatest for 15WDGS, intermediate for 15MIX and 30MIX, and lowest for control and 15WCGF. Treatment diets did not differ in 4% fat-corrected milk production. Compared with the ration containing WDGS, the ration with a 30% mixture of WDGS and WCGF improved nutrient digestibility and N utilization with reduced manure N excretion and increased N retention. Thus, it appears feeding WDGS and WCGF in combination reduces some of the negative effects of feeding WDGS alone.     

Galectin-15 in ovine uteroplacental tissues

Galectin-15 is the newest member of a secreted beta-galactoside-binding lectin family. The galectin-15 gene is expressed specifically by the endometrial luminal epithelium (LE) and superficial ductal glandular epithelium (sGE) of the ovine uterus. The proposed extracellular role of secreted galec7tin-15 is to regulate implantation and placentation by functioning as a heterophilic cell adhesion molecule between the conceptus trophectoderm and endometrial LE, while that of intracellular galectin-15 is to regulate cell survival, differentiation and function. The present study determined galectin-15 expression in uteroplacental tissues during gestation and in the postpartum uterus. In the uterine lumen, secreted galectin-15 was found as multimers, particularly on days 14 and 16 of pregnancy. In the endometrial epithelium and conceptus trophectoderm, intracellular galectin-15 protein was found associated with crystalline structures. Between days 20 and 120 of pregnancy, galectin-15 mRNA was expressed specifically by the LE and sGE of the intercaruncular endometrium of ewes. Immunoreactive galectin-15 protein was most abundant in the trophectoderm with lower levels in the endometrial LE and sGE. Galectin-15 protein was detected in allantoic fluid, but not in amniotic fluid. After parturition, galectin-15 mRNA declined in the endometrium from postpartum day (PPD) 1 to 28 and exhibited a variegated expression pattern in the LE and sGE. These results indicate that galectin-15 is synthesized and secreted throughout gestation by the endometrial LE/sGE and is absorbed by the placenta and forms crystals within the trophectoderm, whereas the remainder is cleared into the allantois after being transported into the fetal circulation via the placental areolae. Based on the biological properties of other galectin family members, galectin-15 is hypothesized to have biological roles in conceptus-endometrial interactions, uterine immune and inflammatory responses, and placental morphogenesis and function.     

Interaction of energy balance, feed efficiency, early lactation health events, and fertility in first-lactation Holstein, Jersey, and reciprocal F1 crossbred cows

First-lactation Holstein (HH), Jersey (JJ), and crossbred cows (HJ and JH, with sire breed listed first, followed by dam breed) were observed for cumulative energy intake (CEI₁₅) and energy used for milk production (CEL₁₅) at wk 15 of lactation in addition to recordings of health problems and pregnancy. Cumulative energy balance (CEB₁₅) was calculated from CEI₁₅ and estimates of expenditures at wk 15 of lactation. Feed efficiency (FE₁₅) was calculated by dividing CEL₁₅ by CEI₁₅. Data included 140 cows with 43, 34, 41, and 22 in the HH, HJ, JH, and JJ groups, respectively. The first incidence of displaced abomasum (DA), ketosis (KET), mastitis (MAST), and metritis (MET) was recorded in the first 100 d of lactation with an incidence of the disease coded as 1 and no incidence coded as 0. Pregnancy (PREG) at d 150 was recorded as 1 if a cow had conceived by d 150 and 0 if she had not. Logistic regression was used to analyze health and fertility with fixed effects in the model including genetic group, linear and quadratic effects for age at calving, and year-season of freshening group. Pregnancy was analyzed with the same variables and the addition of CEB₁₅. In other analyses, CEB₁₅, CEI₁₅, CEL₁₅, and FE₁₅ were response variables with the same explanatory variables plus health events (MAST, DA, MET, and KET), where each health event was a separate analysis. Genetic group effects were significant in the occurrence of MAST and a trend for MET, but were not significant for PREG, DA, and KET. Significant odds ratio for MAST was 19.6 for HJ cows when compared with that for HH cows. Thus, HJ cows were 19.6 times more likely than HH cows to have an incidence of MAST. The trend was for HJ and JH to have a lower odds ratio of MET than that of HH. No other genetic group effects were significant in any of the disease and PREG models. The linear and quadratic terms for age at calving were not significant. An occurrence of MAST decreased FE₁₅ by 5.2 ± 2.2%. Mastitis also decreased CEI₁₅ and CEL₁₅, but the compensatory reductions left the CEB₁₅ unaffected. An occurrence of a DA decreased CEI₁₅ and an incidence of KET decreased CEB₁₅.     

Effects of immunizing ewes against bone morphogenetic protein 15 on their responses to exogenous gonadotrophins to induce multiple ovulations

Sheep with a heterozygous inactivating mutation in the bone morphogenetic protein 15 (BMP15) gene experience an increased ovulation rate during either a natural oestrous cycle or a cycle in which exogenous FSH and eCG (gonadotrophins) are given to induce multiple ovulations. The primary aim of these studies was to determine whether ewes immunised against BMP15 would also show an improved superovulation rate following exogenous gonadotrophin treatment. A secondary aim was to determine the effects of BMP15 immunisation on ovarian follicular characteristics. In most ewes (i.e. > 75%) immunised with a BMP15-keyhole limpet haemocyanin peptide in an oil-based adjuvant in order to completely neutralise BMP15 bioactivity, there was no superovulation response to exogenous gonadotrophins. In ewes treated with exogenous gonadotrophins following a BMP15-BSA peptide immunisation in a water-based adjuvant to partially neutralise BMP15 bioactivity, the ovulation rate response was similar to the control superovulation treatment groups. Characterisation of follicular function revealed that the water-based BMP15-immunised animals had fewer non-atretic follicles 2.5-3.5 or > 4.5 mm in diameter compared with controls. Basal concentrations of cAMP were higher in granulosa cells from animals immunised against BMP15 than control animals. There were no significant differences in the concentrations of cAMP between granulosa cells from BMP15- and control-immunised animals when given FSH or hCG, although there were differences in the proportions of follicles in different size classes that responded to FSH or hCG. Thus, immunisation against BMP15 may have been causing premature luteinisation and thereby limiting the numbers of follicles recruited for ovulation following treatment with exogenous gonadotrophins.     

Phosphoprotein enriched in astrocytes-15 is expressed in mouse testis and protects spermatocytes from apoptosis

Phosphoprotein enriched in astrocytes (PEA-15) is a 15 kDa acidic serine-phosphorylated protein expressed in different cell types, especially in the CN. We initially detected the expression of PEA-15 in primary cultures of Sertoli cells. To assess the presence and localization of PEA-15 in the mouse testis, we studied the expression pattern of the PEA-15 protein by immunohistochemistry and mRNA by in situ hybridization. Both the protein and the mRNA of PEA-15 were localized in the cytoplasm of Sertoli cells, all types of spermatogonia, and spermatocytes up till zygotene phase of the meiotic prophase. Subsequently, with ongoing development of the spermatocytes, the expression decreased and was very low in the cytoplasm of diplotene spermatocytes. To analyze the possible role of PEA-15 in the developing testis, null mutants for PEA-15 were examined. As the PEA-15 C terminus contains residues for ERK binding, we studied possible differences between the localization of the ERK2 protein in wild type (WT) and PEA-15(-/-)mice. In the WT testis, ERK2 was localized in the cytoplasm of Sertoli cells, B spermatogonia, preleptotene, leptotene, and zygotene spermatocytes, whereas in the KO testis, ERK2 was primarily localized in the nuclei of these cells and only little staining remained in the cytoplasm. Moreover, in PEA-15-deficient mice, significantly increased numbers of apoptotic spermatocytes were found, indicating an anti-apoptotic role of PEA-15 during the meiotic prophase. The increased numbers of apoptotic spermatocytes were not found at a specific step in the meiotic prophase.     

巴马火腿酶解物中呈味肽的分离纯化及其结构研究

采用Sephadex G-15凝胶色谱柱分离得到巴马火腿酶解物9个组分,结合感官分析和电子舌测定得出呈味组分为G-15-P2-E2。用半制备RP-HPLC制备此组分中G-15-P2-E2-r1、G-15-P2-E2-r2,并结合串联质谱分析,得出G-15-P2-E2-r1组分可能的氨基酸序列为Leu-Ser-Glu-Arg-Tyr-Pro(LSERYP,LP6)或Asn-Gly-Lys-Glu-Thr (NGKET,NT5),G-15-P2-E2-r2组分可能的氨基酸序列为Pro-Asp-Leu-Pro-Asn-Thr(PDLPNT,PT6)经合成后电子舌测定发现Leu-Ser-Glu-Arg-Tyr-Pro的呈味特性与火腿酶解物呈味特性相近。     

Δ12/Δ15脂肪酸脱饱和酶在发酵食品中应用的研究进展

Δ12/Δ15脂肪酸脱饱和酶在多不饱和脂肪酸合成中起重要作用，是生物体参与脂肪酸代谢途径的关键脱饱和酶类。脂肪酸在发酵食品中益生作用分析成为功能性脂质研究领域的热点话题，调控脂肪酸合成的Δ12/Δ15脂肪酸脱饱和酶应用的研究意义重大。本文首先介绍了Δ12/Δ15脂肪酸脱饱和酶及其参与的脂肪酸代谢途径，其次从植物、动物、细菌、酵母菌、霉菌和藻类6 个方面简述Δ12/Δ15脂肪酸脱饱和酶来源，综述了Δ12/Δ15脂肪酸脱饱和酶在发酵食品应用中的研究，旨在为Δ12/Δ15脂肪酸脱饱和酶研究提供一定的理论参考，为Δ12/Δ15脂肪酸脱饱和酶在发酵食品工业的应用提供新思路。     

西藏灵菇来源酵母菌发酵面团菌株筛选与培养条件优化

从西藏灵菇中分离得到16株酵母菌,测定这16株酵母菌发酵面团的性能,结果表明,菌株Y15发酵力较好,即发酵力17.6mL/(g.h)。菌株Y15发酵的面包色泽呈金黄色,外形饱满,不塌陷,口感酥软,咀嚼时有弹性。对菌株Y15的发酵培养条件进行优化,其最佳发酵条件是:温度20℃,转速180r/min,培养时间16～18h;生理生化鉴定结果表明Y15与木篮假丝酵母相似度为80.2%。     

The application of the lytic domain of endolysin from Staphylococcus aureus bacteriophage in milk

Staphylococcus aureus is a widespread foodborne pathogen that threatens human health. In particular, multidrug-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) are emerging problems in modern health care, food safety, and animal health, which require the development of new antimicrobials to replace overused conventional antibiotics. Dairy products can potentially act as vehicles for the transmission of S. aureus and other antibiotic-resistant strains from the farm into the general human population, and should be controlled during the production and storage process. Recently, bacteriophage endolysins, which degrade the cell wall that is indispensable for bacteria, have been deemed promising antimicrobial agents. In this study, one endolysin, LysGH15, demonstrated prominent antimicrobial efficacy against S. aureus, as did its catalytic domain, cysteine, histidine-dependent amidohydrolase/peptidases (CHAP)_LysGH15 alone. The LysGH15 and CHAP_LysGH15 exhibited different characteristics in one MRSA strain (MRSA 2701), reaching the highest activity under different conditions (35°C and pH 6.0 for LysGH15, 40°C and pH 9.0 for CHAP_LysGH15). A difference in the sensitivity of LysGH15 and CHAP_LysGH15 to NaCl concentration was found, where the lytic activity of LysGH15 depends strongly on its binding domain's binding capacity, which is positively correlated with the NaCl concentration, whereas the CHAP_LysGH15 activity showed a negative correlation with the NaCl concentration. When the NaCl concentration was 450 mM, the lytic activity of LysGH15 reached its peak, whereas the lytic activity of CHAP_LysGH15 was the highest in the absence of NaCl. The difference in NaCl sensitivity between LysGH15 and CHAP_LysGH15 may be due to the sensitivity of the SH3b binding protein of LysGH15 to NaCl. The CHAP_LysGH15 was tested as a biopreservative in whole and skim milk and exerted effective control against S. aureus (declined by approximately 2.5 log₁₀ cfu/mL when incubated at 4°C for 8 h), which suggests promise for application in dairy products.