搅拌桨叶型式对庆大霉素产生菌菌丝形态及其生物合成的影响

六平叶圆盘涡轮桨搅拌产生的剪切力强烈，能达到有效混合，增强氧的传递，而六箭叶圆盘涡轮桨搅拌产生的剪切力较温和，基于庆大霉素产生菌对剪切力敏感的发酵过程特性，在相同的发酵工艺条件下，将六平叶圆盘涡轮桨变换为六箭叶圆盘涡轮桨，实验结果表明剪切力对庆大霉素产生菌棘孢小单孢菌的菌丝形态及其生物合成有显著的影响。在庆大霉素发酵过程中，剪切力相对温和的条件下，菌丝形态、菌体浓度及粘度均有明显的改善，增强了菌丝代谢活力，改变了发酵液的流变学特性，提高了粘度，使产素水平提高48．6％，达到1282μg／ml。     

青霉素菌株（ZPC—1）种子罐发酵工艺的优化

在采用种子罐和发酵罐二级发酵工艺生产过程中 ,由于种子罐装量系数较高 ,故移种时种子液无法被培养基有效地稀释 ,导致粘度高、移种时间长、菌丝长时间缺氧 ,极大地影响了菌丝的生长繁殖以及青霉素发酵生产。为有效地降低种子液的粘度 ,缩短移种时间 ,我们对种子罐发酵工艺进行了优化。种子液为非牛顿液体 ,粘度主要取决于种子液的物质组成和菌丝形态 [1] 。而种子液的物质组成取决于工艺 ,难以进一步优化。故只有通过有效地控制菌丝形态来降低种子液的粘度。我们通过优化搅拌工艺和通气工艺 ,控制了菌丝团直径 ,达到了降低种子液粘度和缩…     

变温培养工艺在林可霉素发酵上的应用

研究在林可霉素发酵的不同阶段采用不同的培养温度对生产菌菌丝形态和发酵单位的影响，改进了林可霉素发酵的传统恒温培养工艺。培养起初60h维持在31℃，随后降到30℃培养70h，再回升至31℃培养至放罐，结果显示：生产菌中、后期菌体浓度下降幅度减小，菌丝上的空泡缩小，美兰染色加深，自溶期推迟；平均单批放罐总亿提高了4．4％，同时可以缓解冷却水水源不足和减轻染菌对发酵水平的影响。     

剪切环境对南昌链霉菌形态和代谢的影响

通过在摇瓶和发酵罐上考察不同剪切环境对南昌链霉菌的代谢过程和菌丝形态的影响 ,并对某些菌丝形态参数进行了定量分析 ,发现南昌链霉菌对剪切的敏感性。在此基础上通过改变发酵罐上搅拌桨叶类型促进了前期菌体生长 ,并使最终发酵效价提高了 5 2     

产黄青霉形态的显微图像分析研究

利用显微图像分析法对产黄青霉的菌丝形态进行了定量研究，并统计分析了青霉素发酵过程中菌线形态的变化规律，具体对菌丝总长度、菌丝生长期的菌丝生长单位、菌丝变异率和菌丝自溶率进行了定量分析。     

隐孔菌不同发酵培养菌丝与野生隐孔菌的糖类成分比较分析

本文采用3，5－二硝基水杨酸为显色剂进行比色，测定隐孔菌不同发酵培养的菌丝及野生隐孔菌的糖类成分，结果表明玉术粉或马铃薯发酵培养基培养的隐孔菌菌丝多糖含量（分别为21．48％和21．58％）均高于野生隐孔菌（17．45％）（P＜0．05），但发酵培养的菌丝间多糖含量无明显差异（P＞0．05）；发酵培养过程中多糖合成是在菌丝中进行，而培养基以还原糖和低聚糖的形式向菌丝中运输；新鲜菌丝在烘干过程中菌丝中还原糖和低聚糖向多糖转化，但总含量不变。     

工业规模产阿维菌素的分批发酵动力学及其流变特性模型

本文主要对除虫链霉菌在150m3发酵罐产阿维菌素分批发酵动力学及其流变特性进行研究,并建立了动力学模型以及相应的发酵液流变特性模型.对模型参数进行了非线性回归的结果显示,预测值与实验值有良好的拟合性,实验值平均偏差在5%左右,表明了这些模型对在150m3发酵罐产阿维菌素的发酵生产具有实际意义.引入菌丝形态分析软件,对发酵过程菌丝球的周长进行了定量计算,并对其与流变参数之间的关系建立模型,这种快速的菌丝形态采集和定量分析手段可用于阿维菌素发酵过程在线实时监控,对快速预测发酵过程阿维菌素产量,及时指导阿维菌素发酵过程提供了一个有效的参数.     

青霉素生产菌原生质体诱变选育

以青霉素生产菌丝状产黄青霉ＪＳ９４－１８为出发菌株制备菌丝原生质体·并对原生质体进行了紫外诱变，筛选到变异株ＪＳ９４－１８－５８，该菌株摇瓶发酵效价比生产菌株提高８．６３％，５０吨发酵罐试生产平均发酵效价比生产菌株提高１０．４０％。     

产黄青霉细胞分化与青霉素生物合成的相关性

目的：通过菌丝细胞在发酵阶段中的分化规律，去了解青霉素生物合成能力的相关性。方法，应用相差显微镜观察产黄青霉在插瓶发酵培养时菌丝形态分化的不同发育阶段。结果：它们分别完成了三个生活循环，每个生活循环中不同分化阶段的菌丝结构东同，功能也不同，结论：根据不同发酵阶段的菌丝细胞分化，可了解和掌握发酵规律。     

搅拌对青霉素发酵菌丝形态及生产率的影响

目的:研究不同发醇规模产黄青霉菌丝形态和青霉素生产率的变化与搅拌转速相关性。方法:用图像分析仪自动测定的菌丝形态参数来分析其与搅拌的关系。结果:产黄青霉随着搅拌转速的提高青霉素的产率降低,有效菌丝长度缩短。结论:以搅拌转速控制菌丝形态,使其保持适当的分支和长度,是获得高产的关键要素之一。     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.     

Alzheimer’s disease – current trends in basic and clinical research. Highlights from the 16th ECNP

Advances in the molecular biological knowledge of neuronal nicotinic acetylcholine receptors (nAChRs) have led to a growing interest by the pharmaceutical industry in the development of novel compounds that selectively modulate nAChR function. The ability of (-)-nicotine, an activator of nAChRs, to enhance attentional aspects of cognition in animals and humans, to exert neuroprotective and anxiolytic-like effects, and presumably to mediate the negative correlation between smoking and Alzheimer's (and Parkinson's) Disease, has focused interest on the potential therapeutic utility of modulators of nAChR function for treatment of some of the deficits associated with these progressive, neurodegenerative conditions. Numerous compounds are known which activate nAChRs and which might serve as lead compounds toward the development of such agents. The pharmacologic diversity of neuronal nAChR subtypes suggests the possibility of developing selective compounds which would have more favourable side-effect profiles than existing agents. This broader class of agents, collectively called cholinergic channel modulators (ChCMs), is anticipated to encompass compounds which would have more favourable side-effect profiles than existing agents, which generally exhibit low selectivity. This selectivity may be achieved by preferentially activating some subtypes of nAChRs (i.e., Cholinergic Channel Activators, ChCAs) or inhibiting the function of other subtypes (Cholinergic Channel Inhibitors, ChCIs). An overview of the biology of nAChRs and the rationale for the use of ChCMs for the treatment of dementia related to neurodegenerative diseases are presented, followed by a discussion of lead compounds and compounds under consideration for clinical evaluation.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.