鸟苷发酵的优化研究

以鸟苷产生菌_{Bacillussubtilis}AJ2 0 66为生产菌株 ,采用 5 0L自控发酵罐与摇瓶培养相结合的联动优化方法对鸟苷发酵进行了研究。谷氨酸钠对鸟苷发酵比较重要 ,培养基中加入 1 %的谷氨酸钠可使 5 0L罐最终产苷达 31 49g/L。次黄嘌呤 (Hx)作为前体可以直接用于鸟苷合成 ,发酵后期加入 0 2 %的Hx,可使 5 0L罐最终产苷达 33 2 4g/L。     

2种国产蝮蛇毒降纤酶的降纤作用比较

目的　比较尖吻蝮蛇毒降纤酶及白眉蝮蛇毒降纤酶降凝血因子 的作用。　方法　选用 1个厂家生产的以尖吻蝮蛇毒为原料的降纤酶及 2个厂家生产的以白眉蝮蛇毒为原料的降纤酶分别治疗 1 7例、 4 0例、 31例急性脑梗死。用降纤酶 1 0 u加入 0 .9%生理盐水 2 5 0 ml中 ,静脉滴注 ,1 h滴完 ,每天 1次 ,共 3天 ,每次用药前用凝固法测定凝血因子 。　结果　 2种白眉蝮蛇毒降纤酶降纤作用不明显 ,尖吻蝮蛇毒降纤作用明显且迅速。用药前 Fg为 4 .0 4± 1 .2 g/L,用药 1次后 Fg降至 2 .1 1± 0 .6 g/L,P <0 .0 1。　结论　尖吻蝮蛇毒降纤酶降纤作用明显优于白眉蝮蛇毒降纤酶。     

前体、诱导子及抑制剂对细胞培养生产紫杉醇的调节作用

研究了前体、诱导子和抑制剂对中国红豆杉细胞培养生产紫杉醇的影响。结果表明 ,它们之间的协同作用对提高紫杉醇的产量有显著影响。其中向培养基中加入 30mg/L 3 甲基 2 丁烯 1 醇 ,2mmol/L苯甲酸钠 ,10mg/L氯化氯胆碱 (CCC) ,10 0 μmol/L茉莉酸甲酯 (MJ) ,0 1mmol/L丝氨酸 (Ser)可以使紫杉醇含量增加 1141 1%。     

昂立一号口服液人群试验

目的 :观察经优化的菌种和目前生产使用菌种发酵的昂立一号口服液人群服用后 ,调节人体胃肠道、代谢、食欲的效果。方法 :采用随机单盲方法 ,改进组 4 4人 ,对照组 2 9人。结果 :人群服用 10、15、2 0d后与服用前比较 :两组服用效果均比服用前差异有显著性 (P <0 0 1) ,改进组比对照组起效略快 ;两组之间服用不同天数 ,效果差异无显著性 (P >0 0 5 )。结论 :由生产菌种及经优化菌种发酵的昂立一号口服液均具有显著调节人体胃肠道、代谢、食欲的功能。     

补料培养提高真养产碱杆菌产3-羟基丁酸和3-羟基戊酸共聚物生产强度的研究

对Alcaligeneseutrophus进行高密度培养 ,研究表明在发酵过程中进行有效控制 ,可以较大幅度地提高 3-羟基丁酸和 3 羟基戊酸共聚物 [P(3HB-co-3HV) ]的生产强度。实验中选择使用限氮的方法积累P(3HB-co-3HV) ,分别采用丙酸和戊酸为 3HV前体 ,对摇瓶种子生长状态 ,停氮时机对菌体生产P(3HB-co-3HV)的影响以及补酸 (3HV前体 )策略进行了研究 ,在 6.6L罐中 ,以葡萄糖为碳源 ,以丙酸为 3HV前体培养 5 0h ,细胞干重 ,PHA产量 ,PHA含量分别达到 149.9g L ,12.49g L ,83.3% (其中 3HV组分占PHA的 12 4mol% ) ,生产强度达到 2.50 (g·h^-1·L^-1) ;以戊酸为3HV前体培养 45h ,细胞干重 ,PHA产量 ,PHA含量分别达到 16.02g L、119 0g L、74.2 % (其中 3HV组分占PHA的17.7mol% ) ,生产强度达到 2.64(g·h^-1·L^-1)     

阿维菌素对棉铃虫的抗性选育及其对解毒酶活性的影响

为了了解棉铃虫对阿维菌素的抗药性机理,用阿维菌素对棉铃虫(Heliothis armigera)进行了抗性选育,并对选育的27代棉铃虫解毒酶的活性进行了检测.选育从F0至F21代,抗性缓慢波动上升,达到选育前的121.19倍;F0至F27代抗性迅速增长,达到选育前的821.73倍,抗性发展趋势呈现S型曲线.随着选育代数...     

广谱重组苏云金杆菌的生产工艺研究

对既杀鞘翅目昆虫又杀鳞翅目昆虫的广谱重组Bt菌株LCJ 0 8,LCJ 12进行了摇瓶发酵和中试发酵。通过 2 .4吨罐发酵试验 ,优化了发酵培养基和发酵条件 ,发酵效价达到 140 0 - 170 0IU/μL(棉铃虫 )和 2 0 0 0CU/μL(柳兰叶甲 )。以直接喷雾干燥和加填充料后喷雾干燥方法生产的粉剂 ,效价分别达到 2 50 0 0 - 34 0 0 0IU/mg和 82 0 0IU/mg。以低倍浓缩工艺生产的悬乳剂 ,毒力效价 2 50 0IU/μL以上。     

益微增产菌在棉花生产上的应用初探

随着科技进步 ,喷施植物生长生化调节剂 ,已成为促进棉花生长发育 ,提高霜前花率 ,增加产量和提高品质的一项栽培措施。为了探索微生态制剂———益微增产菌在棉花生产上的应用效果 ,去年我站选择了四个植棉户进行对比试验 ,现将结果初报如下。1　材料与方法1 1　试验地　土垠肥力中等 ,前茬为密播大麦 ,土质偏砂。1 2　供试材料　品种为泗棉三号 ;益微增产菌为原北京农业大学植物生态工程研究所提供的袋装二代益微增产菌粉剂。1 3　试验设计1 3 1　拌种　四个农户以亩用 2 0 ｇ广谱增产菌加水 2 0 0ｇ拌棉种 1 50 0 ｇ晾干 ,分别各播一…     

应用除莠剂消灭已衰退的子莲种群的初步试验

更新已衰退的子莲种群,是当前植莲生产上需要解决的一个问题。作者通过应用除莠剂消灭莲群的试验,基本上解决了这个问题。莲荷对苯氧乙酸类除莠剂相当敏感。每亩用0．15-0．25市斤的72％2,4-滴丁酯乳油作茎叶喷雾处理,就可彻底“灭荷绝藕”,且对鱼类及其食料生物无不良影响。从子莲进入营养生长盛期起,至盛花期(结藕前)止,均为施药适期。本法对劳力少,且需大面积彻底更新子莲种群或清除野莲的植莲单位,最为适用。     

信息库

1　用朱红密孔菌由草酸生产大量香草醛香草醛 (3 甲 羟基苯甲醛 )是食品工业中应用最广泛的香料之一。市场供应的香草醛有两种 :(1)用愈创木酚化学合成的纯香草醛 ,世界年销量12 0 0 0吨 ,每公斤约 13.5美元。 (2 )从香子兰花荚中提取的天然香草醛 ,每公斤估计价 32 0 0美元 ,年销量约 2 0吨。天然香草醛的价格昂贵 ,研究者一直在探索用生物技术生产天然香草醛。用生物技术生产天然香草醛所需要的天然前体 ,如肉桂酸的衍生物 ,阿魏酸 (4 羟基 3 甲基肉桂酸 )在自然界存在很多 ,主要是在植物细胞壁中和碳水化合物结合成的类酯。阿魏酸可…     

Investigation of the mechanism of temperature sensitivity of the electroreceptors of ampullae of lorenzini

In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980.     

Shapes of curves of pH-dependence of reactions

A simple case is considered in which the rate of a two-step reaction depends on pH because the intermediate formed in the first step has to gain (or lose) a proton before it can react in the second step, and in which the rate-determining step therefore changes with pH. The curves of reaction rate against pH are shown to be symmetrical, and the sharpest peak possible has a width at half its height of 1.53pH units, i.e. of 2log(3+2 radical2). Any particular curve for this situation proves to be identical with a curve that could be generated for the pH-dependence of a single-step reaction in which the rate is proportional to the concentration of a particular ionic form of a reactant. Curves for the latter situation, however, can have forms impossible for the former case in which the rate-determining step changes, but only if the protonations that activate and deactivate the reactant are co-operative. The peak can then become even sharper, and its width at half its height can fall to 1.14pH units, i.e. to 2log(2+ radical3).     

Overview of mechanisms of action of lycopene

Dietary intakes of tomatoes and tomato products containing lycopene have been shown to be associated with decreased risk of chronic diseases such as cancer and cardiovascular diseases in numerous studies. Serum and tissue lycopene levels have also been inversely related to the risk of lung and prostate cancers. Lycopene functions as a very potent antioxidant, and this is clearly a major important mechanism of lycopene action. In this regard, lycopene can trap singlet oxygen and reduce mutagenesis in the Ames test. However, evidence is accumulating for other mechanisms as well. Lycopene at physiological concentrations can inhibit human cancer cell growth by interfering with growth factor receptor signaling and cell cycle progression specifically in prostate cancer cells without evidence of toxic effects or apoptosis of cells. Studies using human and animal cells have identified a gene, connexin 43, whose expression is upregulated by lycopene and which allows direct intercellular gap junctional communication (GJC). GJC is deficient in many human tumors and its restoration or upregulation is associated with decreased proliferation. The combination of low concentrations of lycopene with 1,25-dihydroxyvitamin D3 exhibits a synergistic effect on cell proliferation and differentiation and an additive effect on cell cycle progression in the HL-60 promyelocytic leukemia cell line, suggesting some interaction at a nuclear or subcellular level. The combination of lycopene and lutein synergistically interact as antioxidants, and this may relate to specific positioning of different carotenoids in membranes. This review will focus on the growing body of evidence that carotenoids have unexpected biologic effects in experimental systems, some of which may contribute to their cancer preventive properties in models of carcinogenesis. Consideration of solubility in vitro, comparison with doses achieved in humans by dietary means, interactions with other phytochemicals, and other potential mechanisms such as stimulation of xenobiotic metabolism, inhibition of cholesterogenesis, modulation of cyclooxygenase pathways, and inhibition of inflammation will be considered. This review will point out areas for future research where more evidence is needed on the effects of lycopene on the etiology of chronic disease.