CONCENTRATION AND PURIFICATION OF BACTERIOPHAGE

1. A method for isolating a nucleoprotein from lysed staphylococci culture is described. 2. It is homogeneous in the ultracentrifuge and has a sedimentation constant of 650 x 10^–13 cm. dyne^–1 sec.^–1, corresponding to a molecular weight of about 300,000,000. 3. The diffusion coefficient varies from about 0.001 cm.²/day in solutions containing more than 0.1 mg. protein/ml. to 0.02 in solutions containing less than 0.001 mg. protein/ml. The rate of sedimentation also decreases as the concentration decreases. It is suggested, therefore, that this protein exists in various sized molecules of from 500,000–300,000,000 molecular weight, the proportion of small molecules increasing as the concentration decreases. 4. This protein is very unstable and is denatured by acidity greater than pH 5.0, by temperature over 50°C. for 5 minutes. It is digested by chymo-trypsin but not by trypsin. 5. The loss in activity by heat, acid, and chymo-trypsin digestion is roughly proportional to the amount of denatured protein formed under these conditions. 6. The rate of diffusion of the protein is the same as that of the active agent. 7. The rate of sedimentation of the protein is the same as that of the active agent. 8. The loss in activity when susceptible living or dead bacteria are added to a solution of the protein is proportional to the loss in protein from the solution. Non-susceptible bacteria remove neither protein nor activity. 9. The relative ultraviolet light absorption, as determined directly, agrees with that calculated from Gates'' inactivation experiments in the range of 2500–3000 Å. u. but is somewhat greater in the range of 2000–2500 Å. u. 10. Solubility determinations showed that most of the preparations contained at least two proteins, one being probably the denatured form of the other. Two preparations were obtained, however, which had about twice the specific activity of the earlier ones and which gave a solubility curve approximating that of a pure substance. 11. It is suggested that the formation of phage may be more simply explained by analogy with the autocatalytic formation of pepsin and trypsin than by analogy with the far more complicated system of living organisms.     

雷丸凝集素的纯化及理化性质的研究

雷丸（OmphalialapidescensSchroct．）经过Tris－HCl缓冲液浸提,硫酸铵分级沉淀,离子交换,卵粘蛋白－Sepharose4B亲和层析以及Sephacryl-S100分子筛等步骤,纯化得到纯度为95％以上的雷扎凝集素（简称OLL）。比活提高45.8倍,活力回收2.5％。雷丸凝集素是单一肽链的蛋白质,分子量为12kDa,等电点为7.5,可被半乳糖抑制。具有热稳定性及酸碱（pH1～12）稳定性。2mmol／L氯化锌可使其比活提高4倍。同兔血相比,与人血进行凝集反应,其比活可提高4倍。进行圆二光谱测定,α－螺旋和β-折叠含量较高。与半乳糖间的抑制反应瞬间内完成,且空间结构变得紧密。     

百日咳杆菌去内毒素及保护性抗原的纯化

内毒素(Endotoxin,简称ET)是百日咳全菌苗(Bordetellapertussis vaccine)产生副作用的主要毒素之一,且不易除去。现有的分离方法,如蔗糖密度梯度离心法,较繁琐,成本高。本文采用Sepha-cryl S-300凝胶层折法可以简便有效的去除大部分内毒素。初步毒素试验结果表明:已达到日本生物制品规格的要求。两种保护性抗原FHA和LPF-HA也得到进一步分离纯化,为今后研制高效的百日咳组分菌苗提供了实验条件。     

STUDIES ON BIOLUMINESCENCE : II. THE PARTIAL PURIFICATION OF CYPRIDINA LUCIFERIN

Some solubility, oxidation, reduction, and compound-forming characteristics of extracts of Cypridina luciferin have been presented. A method of purification has been described which increased the amount of luciferin per unit of dry weight, as measured by the total light emitted, to about two thousand times that in the dry starting material. The best yields were from 50 to 65 per cent.     

ON THE TITRATION OF BACTERIOPHAGE AND THE PARTICULATE HYPOTHESIS

1. The theory of the serial dilution method of titration of bacterio-phage has been worked out on the basis of the simple particulate hypothesis. 2. It has been shown that, if the dilution constant is .1, only about 60 per cent of parallel runs on the same solution should give the same end-point, the average being taken over a great number of titrations of each of a great variety of solutions. 3. The discrepancy between this figure, 60 per cent, and Dr. Bronfenbrenner''s estimate, 85 per cent, is considerable. 4. Inasmuch as the particulate hypothesis is well founded, no explanation of the discrepancy is suggested.     

甜菜坏死黄脉病毒的分离提纯及其生物化学特性的研究

本研究工作中,建立了一个有效的甜菜坏死黄脉病毒的分离提纯程序,解决了该病毒粒体易于聚集难以提纯的问题,其操作要点是,(1)通过Sepharose 2B柱层析代替超离心,有效地除去一些小分子量核酸杂质;(2)经PEG再次沉淀浓缩后,调整pH至酸牲(pH3.0),使病毒充分悬浮以减少凝聚;(3)在病毒等电点(pH4.8～4.9)条件下,进一步沉淀以纯化病毒。根据病毒提取物的OD260/OD280比值,算出核酸含量约4.5％。核酸电泳出现4条带,分子量分别为:2.25×10~(?),1.8×10~(?),1.05×10~(?),0.75×10~(?)道尔顿。病毒提取物经超速离心出现4个界面,沉淀系数分别为,200.8S,165S,125.8S,100S。说明甜菜坏死黄脉病毒可能是4组分病毒粒体。病毒粒体含一蛋白亚基,分子量约为2.05±0.05×10~4道尔顿,由16种共199个氨基酸组成。     

人工湿地系统对污水磷的净化效果

建立以亚热带湿生、水生植物为主的十二套下流行一上流－上行流人工湿地系统作为处理城镇生活污水的对策。以其中四套研究其在不同的水力负荷及气候条件下对污水中磷的去除效果。人工湿地系统随处理运行时间的推移趋于稳定,对污水中的总磷、无机磷显示较好的净化效率,平均去除率在冬季达到４０％以上,夏季达到６０％以上,出水达到国家地面水Ⅲ级标准。水生植物在系统中起到明显作用,有植物系统的除磷效率及稳定性均高于无植物对照,其中２号茭白－石菖蒲系统的效果最好,总磷平均去除率为６５％。４号9蔗－苔草系统在高水力负荷下的净效果优于２号。水力负荷的增加对系统的净效果没有明显影响。     

小麦黄矮病毒GPV株系的提纯及血清学研究

小麦黄矮病是危害我国小麦生产的一种重要病毒病害。国内对此病毒的形态结构和提纯方法方面的研究工作已有报道。但对广为应用的蔗糖密度梯度离心法纯化该病毒、提纯病毒的产量估算以及血清学检测技术的研究报告却极少。本文报道我们有关这方面的研究     

细菌乳酸脱氢酶的纯化及其性质研究

从乳酸杆菌发酵液经过两次柱层析,可以得到纯度较高的乳酸脱氢酶,酶的比活力高达６７８．９ｕ／ｍｇ,纯度提高８５．７倍。酶的热稳定性好,ｐＨ稳定范围较宽,在临床上可用于雨氨酸氨基较移酶活力的测定。     

THE GROWTH OF BACTERIOPHAGE

1. An anti-Escherichia coli phage has been isolated and its behavior studied. 2. A plaque counting method for this phage is described, and shown to give a number of plaques which is proportional to the phage concentration. The number of plaques is shown to be independent of agar concentration, temperature of plate incubation, and concentration of the suspension of plating bacteria. 3. The efficiency of plating, i.e. the probability of plaque formation by a phage particle, depends somewhat on the culture of bacteria used for plating, and averages around 0.4. 4. Methods are described to avoid the inactivation of phage by substances in the fresh lysates. 5. The growth of phage can be divided into three periods: adsorption of the phage on the bacterium, growth upon or within the bacterium (latent period), and the release of the phage (burst). 6. The rate of adsorption of phage was found to be proportional to the concentration of phage and to the concentration of bacteria. The rate constant k_a is 1.2 x 10^–9 cm.⁸/min. at 15°C. and 1.9 x 10^–9 cm.⁸/min. at 25°. 7. The average latent period varies with the temperature in the same way as the division period of the bacteria. 8. The latent period before a burst of individual infected bacteria varies under constant conditions between a minimal value and about twice this value. 9. The average latent period and the average burst size are neither increased nor decreased by a fourfold infection of the bacteria with phage. 10. The average burst size is independent of the temperature, and is about 60 phage particles per bacterium. 11. The individual bursts vary in size from a few particles to about 200. The same variability is found when the early bursts are measured separately, and when all the bursts are measured at a late time.     

THE INFLUENCE OF RENNET ON BACTERIOPHAGE MULTIPLICATION IN MILK

SUMMARY: Milk inoculated with 1% starter culture and immediately infected with small numbers of phage particles was afforded protection from phage attack for several hours if rennetted within 30 min of infection. The degree of protection was largely dependent upon the multiplication rate of the phage under test. When rennetting was delayed for 90 min after infection, protection was greatly reduced. The effect of early rennetting was to stimulate cell multiplication and retard the increase of phage. This retardation prolonged the period before equality between cell and phage numbers was reached. Even after equality was reached, acid production continued for some hours in milk that had received early addition of rennet.     

银杏叶聚戊烯醇的化学、纯化和药效研究

通过石油醚提取、水解、萃取和柱层析等分离,制得银杏叶叶聚戊烯醇纯样,其化学结构由NMR、IR和MS鉴定为桦木聚戊烯醇,异戊烯基单元数为15－21。另外,对聚戊烯醇的纯化工艺和毒、药理等进行了研究,提出纯化70％以上聚戊烯醇的方法,适合大指生产,为聚戊烯醇制剂的开发提供基础。     

THE INFLUENCE OF RENNET ON BACTERIOPHAGE INFECTION IN THE CHEESE VAT

SUMMARY: Early gelling of a lightly phage-infected culture of lactic streptococci in milk gave protection against phage attack. This protection was necessary only at acidities of less than 0·33% lactic acid (pH 5·36) and depended on the formation of isolated foci of infection in the gel structure.     

大丽轮枝菌毒素的分离、提纯及生物测定

试验用Czapek's培养液培养大丽轮枝菌(Verticillium dahliae Kleb.)不同致病力类型的5个菌株的培养滤液,经浓缩、离心和透析制成的粗毒素,再经DEAE-纤维素柱层析得到初提毒素,最后通过琼脂糖凝胶过滤层析获得纯毒素样品。生物活性测定表明初提毒素的最低生物活性浓度为5.0—5.5μg/ml。纯毒素的最低生物活性浓度为4.0—4.5μg/ml。配制相同浓度的不同致病力类型菌株的毒素液,它们的培养滤液、粗毒素或纯毒素对棉苗的致萎能力相同。     

THE INFLUENCE OF ACIDITY ON THE MULTIPLICATION OF LACTIC STREPTOCOCCAL BACTERIOPHAGE IN LIQUID MEDIA

SUMMARY: Mass lysis of lactic streptococci infected with baeteriophage at 30° was prevented at pH 5·10. At lower pH values no multiplication of phage followed infection, and prolonged incubation at 30° resulted in loss of phage particles from unlysed samples. Adsorption of phage particles on host cells was unaffected by acidity, but no phage penetration of host cells took place. Host cell properties were apparently unchanged by adsorption of phage particles in acid whey.     

净化污水植物香蒲形态解剖特征的比较研究

用高浓度铅锌废水和清洁水中生长的香蒲Typha latifolia 为材料,制片供显微观察,进行形态解剖特征的比较研究。结果表明:生活在铅锌废水中的香蒲叶表皮细胞变小变方形,出现质壁分离。叶绿体的数量减少,而气孔的数量增加。