影响新疆阿克苏地区棉花质量的主要成因及提升对策

随着新疆阿克苏地区机采棉面积的激增,棉花质量出现下降,存在颜色级下降、长度偏短、成熟度不够等现象。为全面了解阿克苏地区棉花纤维品质变化情况及成因,阿克苏地区农业农村局组织有关人员深入植棉县（市）种子管理站、种业企业、棉花加工企业、棉纺企业、种植大户开展调研。结合调研分析,认为影响棉花质量的主要因素是品种、种植管理、采收、收购和加工工艺等,并从积极发挥政策引导作用,加大优质棉花品种选育与管理,开展配套生产技术研究与规范棉花种植管理,规范棉花采收、加工行为,强化棉花质量监督检查,合力打造品牌棉花,促进信息互联互通等方面提出了相应对策,以期对提升该地区棉花质量起到指导作用。     

中国麇鹿朊蛋白核心片段的原核克隆表达与纯化

从采取的新鲜麋鹿血液中提取麋鹿基因组DNA,通过PCR的方法从麋鹿基因组中扩增麋鹿PrP蛋白核心片段的DNA,并分别在引物的5′和3′端引入EcoRⅠ和HindⅢ两个酶切位点,下游引物将原序列TATTAC突变为TAAT从变成两个终止密码子。通过两个酶切位点将麋鹿PrP蛋白核心片段DNA连接到pET-32a（＋）,转化DH5α,通过酶切鉴定和PCR鉴定,筛选出阳性克隆送菌液测序,从测序结果分析阳性克隆是否符合要求。测序正确后将核心片段基因连接到pET-32a（＋）,阳性质粒命名为MPrP-pET-32a（＋）,阳性质粒转化E.coli BL21（DE3）,进行诱导表达、蛋白质纯化鉴定。     

Effects of different arginine/lysine level on growth performance,body composition and digestive enzyme activity of Macrobrachium rosenbergii

Given the universal presence of antagonism between arginine and lysine, determining the optimal dietary arginine/lysine level is of great importance. In this study, eight diets were formulated to contain different arginine/lysine level, followed by a 9‐week feeding trial with shrimps of 2.10 ± 0.01 cm in length and 0.38 ± 0.02 g in weight to determine the effect of dietary arginine/lysine level on growth performance, body composition and enzyme activity. The results showed that the Diet 6 (arginine/lysine level of 29.4/21.0 g/kg) group had significantly higher weight gain rate, and specific growth rate than the control group and most of the other groups (p < .05) did. Similarly, the retention efficiency of arginine and lysine in the Diet 6 group was significantly higher than the control group and most of the other groups (p < .05). Moreover, most digestive enzymes had higher activity levels in the Diet 6 group, and evident antagonism between dietary arginine and lysine was detected. In summary, dietary arginine/lysine level of 29.4/21.0 g/kg produced the best growth performance, suggesting that a better growth performance in Macrobrachium rosenbergii culture can be obtained by adjusting the dietary arginine/lysine level.     

新城疫不同弱毒株疫苗对鸭免疫效果比较

为了比较新城疫病毒Lasota、B1、Clone30对鸭免疫保护的强弱,我们用Lasota、B1、Clone30弱毒疫苗分别接种非免疫雏鸭,在7、14、21、28、35、45d分别测定其血清效价,比较它们的抗体效价高低,并在45日龄进行强毒攻击,比较它们的免疫保护效果强弱。试验结果显示以NDLasota系对鸭的免疫效果较好。     

纳豆激酶液体发酵条件的优化

利用单因素及正交试验,对纳豆枯草芽孢杆菌(Bacillus subtilis natto)液体发酵生产纳豆激酶(Nattokinase,NK)的培养基组成(碳氮比和离子组成)和培养条件(温度、pH值、发酵时间、接种量和装液量等)对产酶量的影响进行了研究。结果表明,最佳发酵培养基组成及发酵条件分别为:可溶性淀粉2.0%,大豆蛋白胨1.5%,Na2HPO4·12H2O0.4%,KH2PO40.2%,MgSO4·7H2O0.075%,CaCl20.01%,培养温度37℃,pH值7.0,发酵时间24h,转速180r/min,种龄16h,接种量3%,装液量25mL/250mL。在优化发酵条件基础上,进行了5,20L发酵工艺放大的初步研究,在此条件下,摇瓶,5L罐和20L罐发酵酶活最高分别达到915,1086,946IU/mL。     

东海南部海域头足类群落结构特征及其与环境关系

为了研究杜氏枪乌贼(Uroteuthis duvaucelii)角质颚形态和生长特征,根据2015年9—10月在南海北部海域采集的样本,通过测定样本胴长(L_M)、体质量(M)和角质颚的形态值,建立胴长与体质量以及角质颚形态参数与胴长的关系,并利用方差分析法比较不同个体和性成熟度间杜氏枪乌贼角质颚形态的差异。结果表明,不同性别未成熟个体间胴长存在显著差异(P<0.01),雌性不同成熟度个体间体质量存在显著差异(P<0.01),胴长和体质量关系符合幂函数,未成熟和性成熟个体的生长系数b分别为2.22~2.25和1.75;性成熟与未成熟个体间角质颚形态值存在显著差异(P<0.01),不同性别未成熟个体间则不存在显著差异(P>0.05);选取的6个角质颚形态参数值与胴长的关系均符合线性生长模型;通过方差分析,认为不同胴长组之间,雌性杜氏枪乌贼角质颚形态存在显著差异(P<0.01),结合性成熟度分析,发现角质颚形态参数同时受到胴长与性成熟度间交互作用的影响(P<0.01)。     

A Novel Alginate Lyase: Identification,Characterization, and Potential Application in Alginate Trisaccharide Preparation

Alginate oligosaccharides (AOS) have many biological activities and significant applications in prebiotics, nutritional supplements, and plant growth development. Alginate lyases have unique advantages in the preparation of AOS. However, only a limited number of alginate lyases have been so far reported to have potentials in the preparation of AOS with specific degrees of polymerization. Here, an alginate-degrading strain Pseudoalteromonas arctica M9 was isolated from Sargassum, and five alginate lyases were predicted in its genome. These putative alginate lyases were expressed and their degradation products towards sodium alginate were analyzed. Among them, AlyM2 mainly generated trisaccharides, which accounted for 79.9% in the products. AlyM2 is a PL6 lyase with low sequence identity (≤28.3%) to the characterized alginate lyases and may adopt a distinct catalytic mechanism from the other PL6 alginate lyases based on sequence alignment. AlyM2 is a bifunctional endotype lyase, exhibiting the highest activity at 30 °C, pH 8.0, and 0.5 M NaCl. AlyM2 predominantly produces trisaccharides from homopolymeric M block (PM), homopolymeric G block (PG), or sodium alginate, with a trisaccharide production of 588.4 mg/g from sodium alginate, indicating its promising potential in preparing trisaccharides from these polysaccharides.     

羊支原体性肺炎两标准株对抗菌药物敏感性的研究

本实验测定了环丙沙星、氧氟沙星、单诺沙星、红霉素、罗红霉素、泰勒菌素、泰妙菌素、四环素等8种药物对羊肺炎支原体两个标准株Y98和Y-goat的体外抑菌浓度以及红霉素与氧氟沙星、泰勒菌素对Y-goat和四环素与氧氟沙星、泰勒菌素对Y98的联合药敏作用。对羊肺炎支原体两个标准株对抗菌药物的敏感性进行了分析。