酵母菌乳杆菌共培养产谷胱甘肽条件的研究

通过酿酒酵母和干酪乳杆菌共培养,在单因素实验的基础上,考察Plackett-Burman实验、正交实验,优化酵母菌和乳杆菌共培养的条件,以提高酵母菌产谷胱甘肽的产量。首先进行酵母菌和乳杆菌共培养的单因素实验,挑选出乳糖浓度、发酵培养基初始pH值、共培养温度、转速、乳杆菌接种量、接种时间、发酵时间,这7个对谷胱甘肽产量有影响的因素。利用分析软件Minitab16,对这7个因素进行Plackett-Burman实验,筛选出3个影响较为显著的因素。利用分析软件SPSS 19,再对这3个因素进行正交实验,得出最佳发酵条件。在最佳发酵条件下,谷胱甘肽产量比优化前提高了35.14%;相同条件下,比单菌培养提高了33.35%。得到最佳发酵条件为:乳糖浓度40 g/L,发酵培养基初始pH值为6.4,共培养温度为36℃,转速为200 r/min,乳杆菌接种量为8%,乳杆菌接种时间为8 h,发酵时间为24 h。酵母菌乳杆菌共培养产谷胱甘肽的方法具有可行性,并且利用Plackett-Burman设计和正交设计可有效优化发酵条件。     

红缘拟层孔菌液体发酵培养液条件的研究

目的：研究不同培养条件对红缘拟层孔菌菌丝产量和多糖量的影响。方法：通过单因素试验确定液体发酵培养的最佳温度、起始pH值、摇瓶装液量、接种量、摇床转速和发酵天数。结果：最适菌丝体液体发酵的条件是培养温度28℃,发酵液起始pH6.5,250mL摇瓶装40mL培养液,接种量30%,摇床转速175r/min,发酵9d。结论：优选的培养条件有利于提高红缘拟层孔菌菌丝产量和多糖的量。     

埃博霉素产生菌Myxobacteria sp．Ery1369的培养条件优化

对前期筛选得到的埃博霉素产生菌Myxobacteria sp．Ery1369,通过单因素筛选结合正交试验进行发酵培养基优化,同时对摇瓶发酵的主要影响因子温度、转速、初始pH等进行实验探讨,确定了最佳培养条件：土豆淀粉0．8％,酵母提取物0．5％,葡萄糖0．3％,CaCl2·2H200．05％,MSS04·7H200．15％,XAD-163％,初始pH值7．4,种子菌龄72h,500mL三角瓶装液量100mL,接种量20％,摇床转速200r·min^-1,发酵温度30℃;最佳发酵时间为8d,其埃博霉素B产量相比对照提高45％以上,为埃博霉素的工业化生产奠定基础。     

放射型根瘤菌WSH2601生产辅酶Q10的摇瓶发酵条件

以放射型根瘤菌(Rhizobus radiobacterium，WSH2601)作为辅酶Q10的生产菌株。研究了氮源、碳源、接种量、溶氧、初始pH、发酵温度及添加物等因素对细胞生长与产物辅酶Q10合成的影响。结果表明：玉米浆和酶母膏是较好的氮源。葡萄糖与蔗糖是辅酶Q10发酵的较好的碳源。接种量对辅酶Q10发酵的影响不大．为4％。适宜的初始pH值为7，番茄汁能较好地促进细胞的生长。添加玉料浆、L-甲硫氨酸、番茄汁和异戊醇有利于产辅酶Q10；溶氧对细胞生长与产物辅酶Q10合成的影响较显著．通过正交试验初步确定了发酵条件，碳源为1．5g/d1葡萄糖和2．5g／d1蔗糖混合物。酵母膏0．8g／d1．初始pH值7．每500ml装液量为50ml。最后经综合优化条件，在摇瓶发酵条件下：菌体生长量(以干重计)为13．8g／1，发酵液中辅酶Q10产量达到22．9mg／1，比优化前分别提高34％和53％。     

产红色素的三角叶黄连内生真菌发酵条件的优化

目的:对三角叶黄连中一株产红色素的内生真菌进行鉴定,并对其发酵工艺条件进行优化.方法:采用显微鉴定法对目标菌株的菌丝体和孢子的形态特征进行分类鉴定;以红色素效价单位为指标,考察不同的培养基、温度、初始pH、接种量、装液量及发酵时间对红色素产生的影响.结果:通过分离纯化初步鉴定该目标菌株为半知菌类无孢菌群;250 mL摇瓶中产红色素的最佳条件为:PDA培养基、温度为18℃、pH为7.5、接种量为20％、初始装液量为100 mL、最佳发酵时间为11d.结论:该菌株发酵工艺条件优化后能稳定产生红色素,产色素单位可达1.552 U/mL.     

吸水链霉菌FIM-38-24产子囊霉素的发酵条件优化

目的 优化S.hygroscopicus FIM-38-24菌株产子囊霉素发酵条件.方法 采用单因素试验和正交试验研究发酵培养基组成,探讨摇瓶发酵的主要影响因子初始pH值、装液量、转速等发酵参数的影响.结果 确定了适宜发酵培养基和发酵参数:糊精4.5%,葡萄糖1.0%,黄豆粉3.0%,玉米浆粉0.5%,氯化钠0.2%,磷酸氢二钾0.1%,精氨酸0.25%,碳酸钙0.05%,莽草酸0.2%,初始pH 6.5,装液量60mL/500mL,种子菌龄59h,接种量10%,摇床转速250r·min-1,发酵温度28℃,发酵时间5d.优化后的发酵水平较原生产工艺提高50%以上.结论 子囊霉素的优化发酵工艺为其工业化生产奠定了基础.     

基因重组hEGF融合蛋白的发酵条件优化

对hEGF融合蛋白基因工程菌的发酵条件进行优化。结果表明，当起始pH为6．6～7．0，以100ml／500ml的装液量，6％接种量，37℃培养2h，加入0．1mmol／L的IPTG诱导4h后，收获菌体可得到较高的生物量和hEGF融合蛋白表达量。其中IPTG诱导开始时间和菌体收获时间对蛋白表达有显著影响。     

在大肠杆菌中表达重组CotA蛋白的培养条件优化

为了提高大肠杆菌对重组CotA蛋白的表达量,对本实验室构建的含CotA基因表达载体的工程菌株的培养条件进行优化。通过单因素试验及正交试验L18（3 7）优化了产酶的最佳培养条件为：摇床转速为180r／min、装液量为100mL／500mL锥形瓶、接种量为5％、诱导温度25℃、诱导剂IPTG浓度为1．0mmol／L、诱导时间为12h,以及加诱导剂时菌体OD600值为1．0,其中诱导剂IPTG浓度和菌体OD600值对CotA蛋白表达影响显著。     

海洋小单孢菌FIM02523产rakicidin B发酵工艺研究#br#

目的 提高海洋小单孢菌FIM02523发酵液中的生物活性成分rakicidin B含量。方法 采用单因素实验、正交设计实验等方法优化发酵培养基组成比例及培养条件。结果 确定了最优rakicidin B发酵培养基：可溶性淀粉4.0%,蔗糖1.0%,大豆蛋白胨1.0%,酵母粉2.0%,甘氨酸0.1%,NaCl 0.5%,MgSO4 0.05%,CaCO3 0.5%;最优摇瓶发酵条件：发酵周期为120h,接种量5.0%,500mL摇瓶装量100mL,摇床转速220r/min,发酵温度30℃,培养基初始pH值为7.5。结论 优化后发酵工艺rakicidin B的发酵效价较初始工艺提高了约7.3倍。     

产利普斯他汀菌株Streptomyces toxytricini FIM-17-16发酵条件的优化

目的 Streptomyces toxytricini FIM-17-16菌株生物合成利普斯他汀发酵条件的优化。方法 采用单因素试验和正交设计实验相结合的方法,优化Streptomyces toxytricini FIM-17-16发酵培养基和发酵参数。结果 确定了适宜发酵培养基配方和发酵参数：葵花籽油7%,甘油2%,黄豆粉3.25%,麸皮1%,卵磷脂1%,硫酸锌0.01%,碳酸钙0.08%,初始pH自然,装料系数80mL/500mL,种龄20h,接种量15%,摇床转速230r/min,发酵温度28℃,发酵时间168h,产利普斯他汀的水平达到了9667μg/mL,提高了20.6%,发酵周期缩短24h。结论 经过优化发酵条件,S. toxytricini FIM-17-16生物合成利普斯他汀能力大幅提高,为该菌株的工业化生产奠定了基础。     

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.