Cultivar and Environmental Variation of β-glucan Content in Chinese Barleys

β-glucan is a polysaccharide compound closely related to the quality of barley used as malting,feed and food. Low β-glucan content is expected for brewing and feed barley, while high β-glucan content is desirable for food barley. The β-glucan content of barley genotypes collected from various areas of China as well as from Canada and Australia were assayed. Meanwhile a multi-locations trial was conducted to determineβ-glucan content of 10 barley cultivars in 8 locations for two successive planting years. The results showed that barley genotypes from Tibet and Xinjiang had higher β-glucan content and the genotypes with higher than 8%of β-glucan content were detected in Tibet barleys, being valuable for use in the development of healthy food.Barley cultivars being planted now in winter-sowing areas of China had basically the same β-glucan content as those from Canada and Australia. Barley seeds produced in Hangzhou had lower β-glucan content than seeds from the original areas. There was a highly significant difference in β-glucan content among 10 barleys, 8locations and between years. On an average of two years, Xiumei 3 and Kongpei 1 had the highest and lowestβ-glucan content, respectively, and Taian and Hangzhou produced the highest and lowest β-glucan content barley seeds, respectively. Analysis of AMMI model showed that interaction effect between cultivar and environment was highly significant in both experimental years, and was dependent on cuitivar, suggesting that it is important to plant the suitable cultivars in a particular area in order to obtain barley seeds with reasonableβ-glucan content.     

The Variation ofβ-glucan and Protein Content in Barley as Affected by Agronomic Practices

The influences of N applicationrate, timing, sowing date and seeding rate on β-glucan and protein content in barley grains were studied through the field experiments in Hangzhou, China during 1997 -2001. Protein content increased with N application rate and with N proportion applied at late stage. β-glucan content also responded significantly to N application rate and timing, but with different pattern with protein content. Of three N rate treatments, the medium N rate (135 kg ha-1) had the highest β-glucan content, being significantly higher than low N rate (90 kg ha-1) and no difference with high N rate (180 kg ha-1). Among three N timing treatments, two times of N top-dressing at both tillering and booting stage had significantly higher β- glucan content than once N top-dressing at tillering or booting stage. Sowing date has the dramatic effect on both β-glucan and protein content. Protein content decreased with the delayed sowing, and kernel weight showed opposite tendency. Either earlier or later sowing caused increased β- glucan content relative to sowing in early November, which is the normal date for barley sowing locally. Seeding rate had no significant influence on both β- glucan and protein content.     

Effects of Exogenous NSP Enzymes(Xylanase, β-glucanase and Cellulase) on Morphology and Functions of Digestive Tract in Growing Pigs Fed with Paddy-Based Diets

Ninety Landrace X Jia 35±0.40 kg weight growing pigs were randomly allotted to three treatments, each of which was replicated three times with ten pigs per replicate. The pigs were reared on either a conventional corn-based diet (control Ⅰ ) or a paddy-based diet (control Ⅱ ) or a paddy diet supplemented with 0.2% NSP enzymes (test group). All pigs were given ad libitum access to both feed and water. The results of feeding trial showed that supplementation of NSP enzymes significantly increased ADG by 8.78 % (P＜0.05) and decreased F/G by 9.42% (P＜0.05) over the control group Ⅱ. No significant differences were found in ADG and F/G between control group I and the test group. The digestive trial showed that adding NSP enzymes significantly improved apparent digestibility of CP, EE and CF by 18.76 (P＜0.01), 16.04 (P ＜0.05) and 108.57%(P＜0.05), respectively, compared to control Ⅱ. The activities of proteolytic enzyme and α-amylase in duodenal contents were increased by 99.07 (P＜0.01) and 18.41% (P＜0. 05) with the addition of NSP enzymes. No significant differences between test and control Ⅱ group were found in activities of the pepsin in the gastric content, the trypsin and lipase in duodenal contents, the disaccharidase and γ-glutany transferase (γ-GT) in intestinal mucosa, but there was a tendency towards higher activities associated with the NSP enzymes diet (P＞0. 05). The lengths of the villi within the duodenal, jejunal and ileal sections of the small intestine of pigs receiving the NSP enzymes diet were increased by 23.68 (P＜0. 05), 56.00 (P＜0. 01)and 76.90%(P＜0.01) respectively, relative to the pigs in control Ⅱ.     

西藏野生大麦β-淀粉酶活性、β-葡聚糖及蛋白组分含量的基因型与环境变异(英文)

为研究西藏野生大麦籽粒品质性状的基因型与环境变异,分别测定了76份西藏野生大麦在杭州、武汉2地的β-淀粉酶活性、β-葡聚糖和蛋白质组分含量.研究结果表明:籽粒β-淀粉酶活性、β-葡聚糖和蛋白组分含量均存在显著的基因型差异;杭州2006—2007年度种植条件下的β-淀粉酶活性均值和变异幅度最高,且β-淀粉酶活性和β-葡聚糖含量的变异系数和变化趋势恰好相反;4种蛋白质组分中,醇溶蛋白含量与β-淀粉酶活性呈显著正相关.结果明确了西藏野生大麦品质性状变异对于栽培大麦麦芽品质性状改良和功能食品开发具有指导意义.     

Characterization of dual enzyme resulted from bicistronic expression of two β-glucanases in porcine cells

Many animal feed grains contain high β-glucan in the cell wall. Pigs do not secret β-glucanase to degrade the β-glucan in their feed. The indigestible β-glucan not only blocks the release of nutrients from the grain cell wall, but also increases the digesta viscosity in the gastrointestinal tract of pigs. Therefore, dietary β-glucan significantly inhibits nutrient digestion and absorption in pigs. Transgenic expression of β-glucanase in the digestive tract of pigs may offer a solution to solve this problem. In the current study, four artificial codon-optimized β-glucanases genes was prepared and expressed in porcine cells. Only p Bg A and p Egx showed high activity in transfected pig kidney cells. To improve the p H range and p H stability of β-glucanase, the two β-glucanases, p Bg A and p Egx, were co-expressed in pig kidney cells and salivary gland cells by Linker A3 or 2A peptide. The resulting dual enzymes of p Bg A3 p Eg and p Bg2 Ap Eg showed significantly enlarged p H range and significantly increased p H stability, as compared to parental enzymes. These results provide useful data for future study on increasing the feed digestibility of pigs by transgenic expression of β-glucanase in their salivary glands.     

聚糖内切酶EGⅢ的克隆及其在酵母中的表达

[目的]构建可降解纤维类固体废弃物的工程菌.[方法]采用RT-PER方法克隆了绿色木霉(Trichoderma viride)AS313711的葡聚糖内切酶Ⅲ(EGⅢ)的cDNA,测序后构建到酵母表达载体pESP-2上,并通过电击法将其转到酵母感受态细胞中去,得到酵母表达转化子.通过DNS法测定该转化子在不同温度、不同pH值下酶活力的大小.[结果]EGⅢ的cDNA开放阅读框长度为1 257 bp,编码418个氨基酸,推测蛋白质分子量为44.1×103.在pH值为4.9、温度在60℃条件下,EGⅢ酶活力最高,相对酶活为100%.[结论]获得了高表达效率的EGⅢ-T-pESP-2酵母表达载体,其表达活性要比天然的酶高出3～5倍,只要调节好温度、pH值的关系,可提高纤维素葡聚糖内切酶的下游转化纤维素效率,在大规模生产中生产出大量的葡萄糖.     

Effects of dietary yeast β-glucan on nutrient digestibility and serum profiles in pre-ruminant Holstein calves

This study aimed to investigate the effects of dietary supplementation of yeast β-glucan on the nutrient digestibility and serum profiles in pre-ruminant Holstein calves. Forty-two neonatal Holstein calves((39.6±4.2) kg) were randomly allotted to six groups, and each was offered one of the following diets: a basal diet(control) or the basal diet supplemented with 25, 50, 75, 100 or 200 mg of yeast β-glucan kg–1 feed(dry matter basis). The basal diet consisted of a milk replacer and a starter feed. The trial lasted for 56 d. Two digestibility trials were conducted from d 14 to 20 and from d 42 to 48. Blood samples were collected on d 0, 14, 28 and 42 for serum profile analyses. On d 56, three calves from each group were slaughtered, and intestinal samples were collected to assess the villous height, crypt depth and mucosal thickness. Although feed intake was not affected by dietary treatment(P>0.05), the average daily gain(ADG) and gain-to-feed ratios were higher(P<0.05) for the calves fed 75 mg of yeast β-glucan kg–1 feed than those in the other groups. The supplementation of yeast β-glucan at 75 mg kg–1 feed increased the apparent digestibility of dry matter(DM), crude protein(CP), ether extract(EE), and phosphorus(P)(P<0.05) and the ratio of intestinal villous height to crypt depth(V/C)(P<0.05) when compared with the control group. No effects of yeast β-glucan on the serum concentrations of total protein(TP), albumin(ALB), serum urea nitrogen(SUN) and glucose(GLU) were observed(P>0.05). Compared with the control group, supplementation of yeast β-glucan decreased(P<0.05) the serum concentrations of triglycerides(TG) and total cholesterol(TC). The serum concentration of immunoglobulin G(Ig G) and immunoglobulin M(Ig M) increased quadratically(P<0.05), whereas the serum concentration of immunoglobulin A(Ig A) was unaffected by dietary treatments(P>0.05). The supplementation of yeast β-glucan stimulated the enzymatic activity of alkaline phosphatase(ALP)(P<0.05) compared with the control group. The lysozyme(LYZ) concentration increased quadratically(P<0.05) with increasing yeast β-glucan levels. The results suggested that dietary supplementation of yeast β-glucan at 75 mg kg–1 feed improved nutrient digestibility, enhanced immunity by increasing the immunoglobulin concentration and stimulating ALP, and exerted no adverse effects on metabolism in pre-ruminant calves.     

Analysis of Major Carotenoid Composition and Its Content of Citrus Fruit

a-carotene, β-carotene, lycopene, β-cryptoxanthin, zeaxanthin and lutein content of fruits in53 citrus cultivars were determined using HPLC. In both peel and pulp of citrus fruit, the major carotenoidswere lutein, zeaxanthin and β-cryptoxanthin. β-carotene content was relatively low and extremely low was theamount of or-carotene. Among the 53 cultivars tested, lycopene was detected only in pulp of Cara Cara navelorange. Carotenoid content in both peel and pulp of citrus fruit was the highest in Citrus reticulata Blanco andlowest in Citrus grandis Osbeck. Consequently, as far as the health protection value is considered, fruit ofCitrus reticulata Blanco ranks probably higher than other citrus fruits. In fruit of most Citrus retieulatavarities, β-cryptoxanthin was the main carotenoid component in pulp and its amount approximated that of lu-tein in peel. Content of lutein, zeaxanthin and β-cryptoxanthin in peel was about 2.5 - 15 times that in pulp onthe basis of fresh weight. Thus peel was inferred to be the principal location for the carotenoid stock in citrus fruit.     

Concentration Variations of Growth Factors in Colostrum and Normal Milk of Sows

An experiment was conducted to determine the concentration variation of epidermal growth factors (EGF), include insulin-like growth factor-Ⅰ(IGF-Ⅰ), transforming growth factor-beta(TGF-β), and basic fibroblast growth factor (bFGF) in colostrum and normal milk of sows within 35 days after parturition. The results showed that the concentration of EGF, IGF-Ⅰ, TGF-β, bFGF was significantly higher in colostrum than that in normal milk. The concentration of these growth factors in colostrum was significantly decreased with the stage lapse of lactation, and then they remained stable in normal milk. Parity had a slight effect on the concentration of these growth factors.     

β-catenin在藏山羊切牙牙胚发育过程中的表达

研究β-catenin在藏山羊牙胚发育过程中的表达与分布变化,并探讨其在牙齿发育过程中的作用机制。制备藏山羊切牙各期标本,并采用免疫组化方法观察。结果表明,帽状期在星网层、内釉上皮、牙囊均为细胞核阳性表达;钟状早期在内釉上皮、牙乳头细胞核阳性表达;钟状晚期在颈环、牙尖细胞膜阳性表达;成釉期早期在成釉质细胞、成牙本质细胞阳性表达;成釉期晚期均阴性表达。β-catenin在早期牙胚发育中有特定的时空表达模式,通过参与Wnt信号通路和作为黏附分子两种方式,对确定牙胚的形态发生重要作用。     

高产葡聚糖酶微生物的分离筛选

β-葡聚糖是饲料谷物中的主要成分之一,为了帮助动物摄取后更好的消化吸收,选择高产β-葡聚糖酶的微生物作为添加剂以提高饲料的利用率十分必要。从丁香树下土壤中分离具有产β-葡聚糖酶的微生物,通过DNS法测定其产酶活,筛选酶活较高的菌株,测定其生长曲线,并采用分子生物学方法对其进行初步鉴定。结果显示：分离得到3株高产β-葡聚糖酶的菌株,其中菌株D-1酶活力最高可以达到103.67 U·m L^-1。通过对该菌株的生长曲线测,得知其对数生长期在8～24 h。对其进行16S r RNA扩增并构建系统发育树,发现D-1菌株与芽孢杆菌Bacillus sp.同源性达到了99%以上,与蜡样芽孢杆菌聚为一个分支,确定该菌属于蜡样芽孢杆菌。综上,分离菌株可为高产β-葡聚糖酶微生物提供种质资源。     

Genetic Variations Among Liriomyza sativae Blanchard Populations Indicated by β-tubulin Gene Sequences

To analyze the genetic differentiation of the host- and geo-populations of Liriomyza sativae Blanchard, the β-tubulin gene of 5 host-populations and 6 geo-populations of L. sativae was sequenced. Subsequently, the sequences were analyzed by biosoftware DNAStar and MEGA, and the phylogenetic trees constructed. The results obtained by the two softwares were similar, that is, the sequences of β-tubulin gene were more than 98% homologous, among the host- and geo-populations of L. sativae, with only 8 variable sites, but no insertions and deletions were detected. It seems that differentiations in β-tubulin gene among the host- and geo-populations of L. sativae are related to the hobby to hosts and the geographical distributions, respectively.     

The development of the 2, 4-dienoyl CoA reductase 1 gene （DECR 1） in pig

2,4-dienoyl CoA reductase gene(DECR 1)is mapped on pig 4 q 1.2,includes ten exons and nine introns of variable size that span 30 kb.DECR 1 gene participates in theβ-oxidation pathway,affects the content of intramuscular fatty acid,especially the percentage of linoleic acid.The expression of DECR 1 gene has important influence on IMF,the pH,and the meat colour of pork, further affects the meat quality.     

β-葡聚糖对啤酒易滤性影响的研究

通过对啤酒中β-葡聚糖的定性定量分析和啤酒易滤性的测定,发现溶解状态的β-葡聚糖对啤酒的过滤没有明显的影响,而β-葡聚糖凝胶对啤酒过滤有严重影响.啤酒中β-葡聚糖凝胶的分子量在300 000以上,当含量达到20 mg/1时,就会使啤酒膜过滤困难.啤酒的易滤性与β-葡聚糖含量之间里r=-0.222的不显著负相关,而与β-葡聚糖凝胶的含量之间呈r=-0.841~(***)的极显著负相关.     

重组β-CPP二聚体真核表达载体的构建及表达产物的结构分析

β- CPP作为一种促进 Ca2 + 等离子吸收和细胞融合的活性短肽有着广泛的应用前景。为深入研究其生物学功能 ,采用基因工程方法得到β- CPP的二聚串联体基因并以此为基础构建真核表达载体 ,对其结构进行分析 ,为进一步表达重组β- CPP二聚体蛋白奠定基础。