微生物絮凝剂的研制——菌种选育、絮凝效果及提取工艺

从土壤、河泥、活性污泥中分离出 75 2株细菌 ,以发酵液对高岭土悬浮液絮凝效果中国石油化工股份有限公司科学技术研究开发资金资助项目 (No . 990 0 1 8)收稿日期 :2 0 0 0 0 4 0 3 ,修改日期 :2 0 0 0 1 2 3 0为指标 ,筛选出 1株絮凝剂产生高效菌。该菌在实验室培养条件下 ,以 0 2mL/3 0mL接种量 ,5h种龄的种子液接种 ,2 5℃、pH7摇床培养 3d可达最高絮凝活性。最佳培养基配方为 :葡萄糖 2 0g ,尿素 0 3g ,酵母膏 0 6g ,Na     

THE PERMEABILITY OF CELLS FOR OXYGEN AND ITS SIGNIFICANCE FOR THE THEORY OF STIMULATION

It can be demonstrated by an indicator method that living cells are as freely permeable to oxygen as dead cells, and that sudden admission of oxygen to the cell cannot account for increased oxidation as a result of stimulation. Oxygen penetrates as readily as carbon dioxide among the acids and ammonia among the alkalies. Exposure of living plant cells to high oxygen pressures does not initiate certain oxidations (except after some hours), which proceed readily in dead plant cells in the air. In the light of the preceding statement, about the permeability of cells for oxygen, this is interpreted to mean that more oxygen enters the cell at high pressure, but that the reacting substances (chromogen and oxidase) are kept apart by some phase boundary as long as the cell is alive. Increased oxygen concentration eventually produces injury to the cell.     

小麦品种电泳分类鉴定技术的标准化研究

在甘氨酸-乙酸缓冲系统(pH 3.10)下采用9％聚丙烯酰胺凝胶电泳,比较研究了小麦(Triticumaestivum L.)“烟农15”、“济南13”、“莱州95”和“Marquis”品种的醇溶蛋白图谱误差变化及其有关控制方法。在每个凝胶板上误差呈规律性变化,迁移距离越大,谱带误差越大。同2.05cm谱带相比,9.25cm谱带标准误为0.0332,增大2倍;极差由1.5mm增大到4.5mm。国内3个小麦品种“莱州953”、“济南13”和“烟农15”群体内不存在电泳生物型。“莱州953”由于深色谱带多、分布合理,可作为基本电泳参照品种;“济南13”则由于总带数和特有谱带多,可作辅助参照品种。根据筛选的2.05、3.15、6.05和9.25cm标志带及其实际迁移大小,计算各电泳道谱带的矫正系数和矫正迁移距离。这种移动矫正法能使图谱误差降低约2/3。     

玉米赤霉烯酮单克隆抗体酶联免疫测定方法的建立及初步应用

用ZEN—BSA人工抗原免疫BALB／c鼠,经融合、筛选和克隆化得到可稳定分泌抗ZEN单克隆抗体的杂交瘤细胞株ZEN—lC6。zEN一lC6属IgG₁,纯化腹水抗体效价为10^-5,与5种衍生物的交叉反应系数为0.16～1.20％。用ZEN一1C6建立了检测食品(玉米、小麦、大米)中玉米赤霉烯酮的CIEIA法。该法检测纯毒素的线性范围为5～1000ng／ml,最低检出浓度为0．1ng／ml,平均回收率为84．0～105．5％。用该法测定了81份样品,均有ZEN毒素检出。