超氧化物歧化酶模拟化合物的生物活性研究

根据天然超氧化物歧化酶(SOD)活性部位结构合成了含苯并咪唑的5种配体及其32种分别含Cu（Ⅱ）、Fe（Ⅲ）、Mn（Ⅱ）、Co（Ⅱ）的模拟化合物.经光谱、电化学测试证明这些化合物具有拟S3D活性,其50％抑制率浓度（IC50）为10-6～10-8mol·L-1,催化超氧离子自由基（O-·2）歧化的反应速率常数kq为106～108mol-1·L·s-1.同时观察到几种模拟化合物有抗肿瘤活性或增强水稻抗寒性.     

检测香蕉花叶心腐病病原CMV的PAS—ELISA方法的改进

作为一种快速、敏感的免疫学方法,ELISA已被广泛地用于植物病毒的研究与应用性检测方面。在实验室中用PAS-ELISA检测香蕉花叶心腐病病原CMV已被证明是一种获得无CMV组培苗的有效手段。在香蕉无病毒组培苗工厂化大批量生产中,我们应用此法作为质量控制的手段之一,剔除病苗,保证产品不带CMV,获得一定成效。但同时我们也发现,香蕉组织中含有引起非特异性吸附反应的物     

三尖杉的组织培养－紫杉醇来源的新途径

从三尖杉当年生幼茎和未成熟假种皮诱导出了愈伤组织,对愈伤组织进行了培养研究,ＨＰＬＣ分析表明其紫杉醇和１０－ｄＡＢⅢ分别为细胞干重的０．００２０９％和０．０１２２％。三尖杉可望成为紫杉醇来源的新途径。     

20-羟基蜕皮酮对蓖麻蚕蛹体液免疫的调节作用(英)

本研究指出20—羟基蜕皮酮(20-OHE)参加蓖麻蚕蛹对大肠杆菌的体液免疫反应。20-OHE的作用方式是多方面的,包括提高血淋巴蛋白质含量,产生抗菌蛋白,增加溶菌酶活性,和激活原酚氧化酶系统。这表明多个免疫控制系统参与蓖麻蚕蛹体液免疫反应的可能性。     

新型气升式反应器在发酵培养中的应用研究

本文以Ｌ－苹果酸生产为例,采用新型的分段内循环气升式反应器分批培养产延胡索酸酶的产氨短杆菌ＭＡ－２,并与同等规模机械搅拌反应器中接着的结果相比较。数据表明,采用气升式发酵设备进行培养,该菌体的收率能提高近３％,且发酵周期能缩短一半左右,显著降低培养成本,该类型的反应器具有广阔的应用前景。     

马铃薯人工种子的研究

本研究以虎头（Ｈ）、克四（Ｋ）和Ｆａｖｏｒｉｔａ（Ｆ）三个品种的马铃薯不定芽在液体培养条件下诱导生成的微型薯为试材,经筛选后获得的大小一致的微型薯经过适度的低温处理后,用４％的海藻酸钠和２％的氯化钙溶液,在附加一定的植物激素条件下,进行人。种皮包埋形成人工种子。在无菌条件下,三个品种的人工种子萌发率均达９０％以上。在土壤中,人工种子萌发率可达６０％以上,萌发的人工种子中８０％能够形成生长发育正常的完整植株。     

REGULATORY ROLE OF 20-HYDROXYECDYSONE ON HUMORAL IMMUNITY IN THE PUPAE OF THE INDIAN SILKWORM,PHZLOSAMIA CYNTHIA RICINI*

Abstract The present study shows that 20-hydroxyecdysone(20-OHE) participates in the humoral immune responses of Philosamia Cynthia ricini, either normal or debrained pupae, to the E. coli. The mode of action of 20—-OHE is multiple. It raises hemolymph protein content, makes antibacterial proteins be produced, increases lysozyme activity, and activates prophenoloxidase system. It is possible that several immune control systems are involved.     

Identification of a penicillin-binding protein 3 homolog, PBP3x, in Pseudomonas aeruginosa: gene cloning and growth phase-dependent expression.

A homolog of Pseudomonas aeruginosa penicillin-binding protein 3 (PBP3), named PBP3x in this study, was identified by using degenerate primers based on conserved amino acid motifs in the high-molecular-weight PBPs. Analysis of the translated sequence of the pbpC gene encoding this PBP3x revealed that 41 and 48% of its amino acids were identical to those of Escherichia coli and P. aeruginosa PBP3s, respectively. The downstream sequence of pbpC encoded convergently transcribed homologs of the E. coli soxR gene and the Mycobacterium bovis adh gene. The pbpC gene product was expressed from the T7 promoter in E. coli and was exported to the cytoplasmic membrane of E. coli cells and could bind [3H] penicillin. By using a broad-host-range vector, pUCP27, the pbpC gene was expressed in P. aeruginosa PAO4089. [3H]penicillin-binding competition assays indicated that the pbpC gene product had lower affinities for several PBP3-targeted beta-lactam antibiotics than P. aeruginosa PBP3 did, and overexpression of the pbpC gene product had no effect on the susceptibility to the PBP3-targeted antibiotics tested. By gene replacement, a PBP3x-defective interposon mutant (strain HC132) was obtained and confirmed by Southern blot analysis. Inactivation of PBP3x caused no changes in the cell morphology or growth rate of exponentially growing cells, suggesting that pbpC was not required for cell viability under normal laboratory growth conditions. However, the upstream sequence of pbpC contained a potential sigma(s) recognition site, and pbpC gene expression appeared to be growth rate regulated. [3H]penicillin-binding assays indicated that PBP3 was mainly produced during exponential growth whereas PBP3x was produced in the stationary phase of growth.     

甘蔗细平象的研究

甘蔗细平象Trockorhopalus humeralis Chevrolat是云南甘蔗上的一种毁灭性地下害虫,以幼虫和成虫在地下蔗头内为害,为害期8-10个月。据1989年调查,受害蔗每亩损失500-3000kg,严重的无收。此虫1年发生1代,以成虫在蔗头内越冬,有喜湿性,不能飞翔,主要通过沟河流水传播。在河川坝地,沙壤土中虫口较多;宿根年限越长的甘蔗受害越重。建议蔗稻轮作;缩短甘蔗宿根年限;早春翻挖有虫蔗蔸烧毁;结合新植蔗下种,宿根蔗松蔸培土施用甲基异柳磷或铁灭克等颗粒杀虫剂进行防治。