犬源乳酸菌高密度培养条件的优化

本文研究了犬源乳酸菌生长繁殖的环境条件（温度、接种量、起始pH等）和培养基组成（氮源、碳源等）,优化确定了犬源乳酸菌密度培养的适宜培养条件为：起始pH为6.5,培养温度为37℃,培养基配比为麦芽糖∶乳糖（1∶1）2%、牛肉浸膏1.0%、缓冲盐A0.5%,NaCl 0.25%,MgSO40.1%,接种量5%,结合优化的培养条件,可使犬源乳酸菌活菌数得到进一步提高。     

纳豆菌产生抗菌物质的培养条件的优化

对纳豆菌产生抗菌物质的培养基的组成进行了优化,并探讨了温度、pH、培养方式和接种量对纳豆菌生长及抗菌作用的影响,发酵的适宜温度为25℃－30℃,培养基的最适初始pH为6．5－7．5,最适接种量6％,振荡培养优于静置培养。     

浮萍棘尾虫Adss基因克隆及表达载体构建

为研究腺苷酸基琥珀酸合成酶(Adenylosuccinate synthase, 简称Adss)在原生动物中的作用, 对浮萍棘尾虫(Stylonychia lemnae)腺苷酸基琥珀酸合成酶Adss基因进行PCR克隆, 获得全长为1396 bp左右的序列, 其编码458个氨基酸, 保守结构域含有一个P-loop NTPase结构域, 蛋白结构预测Adss蛋白是由α-螺旋、β-折叠和无规卷曲组成的复杂结构。多重序列比对和系统进化分析显示浮萍棘尾虫Adss蛋白与第四双小核草履虫、多子小瓜虫和嗜热四膜虫等纤毛虫同源性较高。通过克隆浮萍棘尾虫Adss基因的启动子序列, 并采用增强型绿色荧光蛋白EGFP作为报告基因, 构建了启动子序列调控的表达载体pEGFP-N1-Adss, 通过转染细胞确定浮萍棘尾虫Adss蛋白定位于细胞质中。文章报道了原生动物纤毛虫Adss基因, 证实浮萍棘尾虫Adss蛋白属于典型的真核生物Adss, 为进一步揭示Adss在单细胞真核生物中的作用机制提供了新的参考。     

杏鲍菇液体培养研究初报

采用液体摇瓶培养方法,对杏鲍菇适宜的液体培养基和液全培养条件（适宜温度,摇瓶装量,摇瓶转速,接种量,培养基初始pH等）进行了探讨。结果表明,杏鲍 菇适宜的液体培养基为：葡萄糖3%,蛋白胨0.2%,KH2PO40.05%,MgSO40.05%,pH6.5,适宜的液全培养条件为：培养温度25℃,培养基的初始pH6.5,摇瓶装量100-140ml/500ml,摇瓶转速150r/min,接种量10%,最佳培养时间7d。     

产碱性木聚糖酶芽孢杆菌HSⅠ的筛选及发酵条件研究

通过碱性培养基分离到耐碱的芽孢杆菌HSⅠ,研究了碳源,氮源,培养温度,培养基起始pH,培养时间,接种量,通气量,添加物对HSⅠ菌产木聚糖酶的影响。测定出其产酶最佳培养条件;麸皮6%,（NH4）2SO40。2%,NaNO30.4%。蛋白胨0.6%,起始pH为10.5,接种量为5%,250mL三角瓶装液量为50mL。最佳培养温度为37℃,培养时间为96h,其酶活力最高达54IU/mL。     

草酸青霉BZH-2002果胶酶固体发酵条件研究

对草酸青霉菌(Penixillium oxalicum)BZH-2002菌株固体发酵果胶酶的主要影响因子温度、初始pH值、含水量及接种量进行了实验探讨,确定了最佳培养条件：温度为30℃,初始pH值为4．8,固体培养基含水量控制在30～35ml/10g甜菜渣,接种量3～4%。同时对该菌株固体发酵提取液中果胶酶的酶学特性进行了初步研究,结果表明,该酶最适反应温度和pH分别为55℃和pH4．8,在40℃温度下和pH3．5～5．5范围内,酶活性较稳定。     

海洋真菌岩藻多糖酶的固态发酵条件研究*

本文对海洋真菌Dendryphiella arenaria(TM94)岩藻多糖酶的固态发酵条件进行了研究,主要内容包括碳源、氮源、添加物、起始pH、接种量及温度等.固态发酵最佳培养基组成麸皮7.5g,葡萄糖0.5g,海带粉0.6g,NaNO3为4g/L最佳培养条件为培养温度28℃,起始pH6,接种量3ml(孢子浓度为106个/ml).在28℃培养24h,酶活力可达35.5IU/g干培养基,比活力为1.39IU/mg蛋白质.对岩藻多糖酶酶学性质也进行了研究.     

绿色木霉在啤酒糟基质上产纤维素酶条件的优化

对绿色木霉接种到啤酒糟固态发酵产纤维素酶的培养基和培养条件进行优化,考察发酵物料起始含水量、发酵时间、起始pH值等发酵条件,以及啤酒糟培养基中添加麸皮、氮源种类对产酶的影响。结果表明,以啤酒糟为发酵基质接种绿色木霉生产纤维素酶是可行的。经单因素和正交试验获得最适固态发酵的培养条件为:起始pH 5~6,培养温度28~30℃,发酵4 d;最佳发酵培养基组合为:麸皮比例30%,培养基起始含水量50%,(NH₄)₂SO₄添加量为2.0%~2.5%。     

两歧双歧杆菌86321生长特性的研究

目的研究两歧双歧杆菌86321的生长特性,为该菌生理功能研究和高效发酵剂的研制提供理论依据。方法通过生长曲线、产酸量、最适厌氧方式、最适pH、最适培养温度及最适接种量等一系列实验,对两歧双歧杆菌86321进行生长特性的研究。结果两歧双歧杆菌86321在BL培养基中培养时间可缩短至16 h,最高活菌数的lg值达到9.5;其最适厌氧方式为自然厌氧法或密封法,装液量视实际情况而定;在pH7.08.0生长良好,最适初始pH为8.0;在3742℃生长良好,最适温度为37℃;综合总菌量和生产成本,确定最适接种量为7%（v/v）。结论用BL培养基可以大大提高两歧双歧杆菌86321的产量。细菌产量的高低和发酵速度的快慢与菌种活力、厌氧方式、培养温度及pH等因素密切相关。     

培养条件对一株木霉产纤维素酶过程影响的研究

采用固态发酵和连续监测正交实验结果的方法,研究了培养温度、初始pH值、液料比和接种量对一株木霉(Trichodermasp.)发酵过程中微晶纤维素酶活、CMC酶活和滤纸酶活的影响及影响程度。指出液料比在整个发酵过程中是对产酶影响最大的因素,温度在发酵初期影响较大,初始pH和接种量的影响均不显著。总体看来,培养温度、初始pH值、液料比和接种量分别为30℃、4、7和5%是比较合适的。     

RAPID ALDOSTERONE-INDUCED CELL VOLUME INCREASE OF ENDOTHELIAL CELLS MEASURED BY THE ATOMIC FORCE MICROSCOPE

Atomic force microscopy (AFM) is a useful technique for imaging the surface of living cells in three dimensions. The authors applied AFM to obtain morphological information of individual cultured endothelial cells of bovine aorta under stationary and strain conditions and to simultaneously measure changes in cell volume in response to aldosterone. This mineralocorticoid hormone is known to have acute, non-genomic effects on intracellular pH, intracellular electrolytes and inositol-1,4,5-triphosphate production. In this study whether endothelial cells under tension change their volume in response to aldosterone was tested. Such changes were already shown in human leukocytes measured by Coulter counter. In contrast to leukocytes that are more or less spherical and live in suspension, endothelial cells exhibit a complex morphology and adhere to a substrate. Thus, measurements of discrete cell volume changes in endothelial cells under physiological condition is only feasible with more sophisticated techniques. By using AFM we could precisely measure the absolute cell volume of individual living endothelial cells. Before the addition of aldosterone the cell volume of mechanically stressed endothelial cells mimicking arterial blood pressure was 1827±172fl. Cell volume was found to increase by 28% 5min after hormone exposure. Twenty-five minutes later cell volume was back to normal despite the continuous presence of aldosterone in the medium. Amiloride, a blocker of the plasma membrane Na⁺/H⁺exchanger prevented the initial aldosterone-induced volume increase. Taken together, AFM disclosed a transient swelling of endothelial cells induced by the activation of an aldosterone sensitive plasma membrane Na⁺/H⁺exchanger.     

Hybridoma growth and productivity: effects of conditioned medium and of inoculum size

Apart from gas concentrations, temperature, and pH, generally only the initial conditions can be manipulated in batch culture. Inoculum size and initial conditioned medium concentration represent two important considerations for optimal batch production. Two hybridoma cell lines were used to assess the impact of these initial conditions on population growth and monoclonal antibody productivity in suspension batch culture. Varying initial cell concentration over the range of 1.0 × 105 cells mL-1 to 3.0 × 105 cells mL-1 did not affect maximum product titre or maximum volumetric cell-hours attained. Initial percent of conditioned medium up to 40 percent strongly impacted on population growth and productivity, with initial levels of 30 to 40% conditioned medium reducing or eliminating lag phase and increasing average viable cell density. However, specific productivity and product titre declined with increasing initial percent conditioned medium, even on a per volume of fresh medium basis. Glutamine and glucose depletion or ammonia toxicity could cause depressed product titres when conditioned medium is used. Glutamine and glucose levels can easily be replenished in conditioned medium at minimal cost, and ammonia can be removed. Specific productivity was higher during cyclic batch operating mode than during batch operating mode. This may be because cyclic batch operating mode results in an incidental volume of conditioned medium at the beginning of each cycle. A two stage, cyclic-batch/batch operating mode can be employed to fully utilize medium and maximize product titre.     

EFFECT OF FERMENTATION PARAMETERS ON BIO-ALCOHOLS PRODUCTION FROM GLYCEROL USING IMMOBILIZED Clostridium pasteurianum: AN OPTIMIZATION STUDY

This article addresses the issue of effect of fermentation parameters for conversion of glycerol (in both pure and crude form) into three value-added products, namely, ethanol, butanol, and 1,3-propanediol (1,3-PDO), by immobilized Clostridium pasteurianum and thereby addresses the statistical optimization of this process. The analysis of effect of different process parameters such as agitation rate, fermentation temperature, medium pH, and initial glycerol concentration indicated that medium pH was the most critical factor for total alcohols production in case of pure glycerol as fermentation substrate. On the other hand, initial glycerol concentration was the most significant factor for fermentation with crude glycerol. An interesting observation was that the optimized set of fermentation parameters was found to be independent of the type of glycerol (either pure or crude) used. At optimum conditions of agitation rate (200 rpm), initial glycerol concentration (25 g/L), fermentation temperature (30°C), and medium pH (7.0), the total alcohols production was almost equal in anaerobic shake flasks and 2-L bioreactor. This essentially means that at optimum process parameters, the scale of operation does not affect the output of the process. The immobilized cells could be reused for multiple cycles for both pure and crude glycerol fermentation.     

10升气升环流式生物反应器培养紫草细胞

本文采用自行设计研制的10升气升环流式生物反应器培养紫草细胞,培养周期34d．前14d为细胞生长培养,细胞生长呈正常的S型曲线,细胞增长到原细胞接人量的4倍．后20d为紫草色素生产培养,细胞增长到32倍。整个周期每升培养液可生产紫草色素0．6g,在反应器中,培养液pH值的变化与细胞生长呈正相关,与紫草色素的形成呈负相关,pH值变化规律可用于监测紫草细胞在生物反应器的生长和色素形成．     

几种生理因子对印楝细胞悬浮培养生长的影响

通过研究不同生理因子对印楝悬浮细胞生长的影响 ,建立了一种快速生长的印楝细胞悬浮培养体系。结果表明 ,在添加了 6 BA 0 .8mg/L、NAA 0 .8mg/L、蔗糖 3 0 g/L且初始 pH值为 5 .8的MS培养液中 ,以 60g/L的接种量进行印楝细胞的悬浮培养 ,细胞生长速率可达 4.49g/L·d。     

小鼠胚胎神经干细胞的分离培养及其鉴定

且的探索小鼠胚胎神经干细胞的体外培养方法,并获取高纯度的神经干细胞,为神经干细胞的深入研究提供实验材料。方法无菌条件下分离E15天小鼠胚脑皮质,制成单细胞悬液,在bFGF和B27存在的培养基中培养扩增,通过免疫细胞化学染色鉴定神经干细胞及其子代细胞的分化方向。结果培养的部分细胞在B27和bFGF存在的无血清培养基中可以在体外分裂增殖,同时表达神经干细胞特异性抗原nestin,并在撤出B27和bFGF的有血清培养基中向神经细胞和胶质细胞分化。结论小鼠胚脑皮质存在具有多向分化潜能的神经干细胞,这些细胞可以在体外稳定培养、传代并自然分化,为细胞替代治疗提供了理想的细胞来源。     

Prototype of a novel autonomous perfusion chamber for long-term culturing and in situ investigation of various cell types.

In the context of a neurobionic approach to chemical analysis and sensorics, this article depicts the development of a miniaturized autonomous perfusion chamber setup for the growth and the electrical as well as optical investigation of (neural) cell cultures in vitro. We suggest an autonomous, modular, temperature-controlled, transparent, and sealed perfusion cell culture housing adaptable to various mounts, sizes and different needs. The design includes the electronics of a temperature and medium supply control unit. The setup combines the possibility of uninterrupted cell culturing with simultaneous microscopic and analytical investigation of variable amounts of cells or organs of human, animal, or plant origin under sterile conditions on different substrates without the need of an external incubator or a sterile working environment. Its use is demonstrated exemplarily with neuronal cultures from embryonic chicken that were cultured in a prototype system for 3 weeks. It turned out that cell survival in such a chamber was prolonged with timed medium flow rather than continuous perfusion.     

pH值、激素对新疆紫草悬浮培养细胞生长及紫草宁衍生物合成的影响

报道了不同ｐＨ值、激素对新疆紫草悬浮培养细胞生长及紫草宁衍生物合成的影响。结果表明,新疆紫草细胞具有自我调节其培养液ｐＨ值的功能。适合于细胞生长及紫草宁衍生物形成的ｐＨ值为５．６±０．４０。ＢＡＰ、２,４－Ｄ、ＮＡＡ或ＩＢＡ对细胞生长无显著的促进作用,且都会抑制紫草宁衍生物的形成。在生长培养基中添加１．０ｍｇ／ｌ　ＩＡＡ和０．５ｍｇ／ｌＫＴ可促进细胞生长,而在生产培养基中附加０．１ｍｇ／ｌＫＴ和０．７５─１．０ｍｇ／ｌＩＡＡ则有利于紫草宁衍生物含量及产量的提高。     

THE CYTOTOXIC PRINCIPLE OF THE PHYTOFLAGELLATE PRYMNESIUM PARVUM

The cytotoxic events leading to lysis induced in Ehrlich ascites tumor (E.A.) cells by Prymnesium parvum cell extracts were followed microscopically and measured quantitatively as changes in E.A. cell volume, uptake of trypan blue, and release of macromolecular constituents from the cells. Cell swelling was the most immediate response to P. parvum cytotoxin, while cell death and lysis were later events distinguished by a decline in cell volume, uptake of dye, and appearance of cellular macromolecules free in the incubation medium. The pH and temperature were shown to affect the outcome of the lytic sequence. At either low pH or temperature, cells swelled but did not lyse until the pH or temperature was raised. On the other hand, cells swollen at the higher pH or temperature could be protected from lysis by lowering either the pH or the temperature.     

Factors affecting the hemolytic action of "lysolecithin" upon rabbit erythrocytes

1. Lysolipid was prepared by the action of snake venom on egg yolk, and a study was made of the factors affecting its hemolytic action upon rabbit erythrocytes. 2. Lysis proceeded very rapidly at first, then ceased within a few minutes at room temperature. A given amount of lysin appeared to hemolyze a fixed number of cells, under specified conditions. 3. The more dilute erythrocyte suspensions required relatively more lysin per cell, for 50 per cent hemolysis of the suspension. There may be an equilibrium between the lysin dissolved in the medium and that adsorbed on the cells. 4. The degree of hemolysis for varying lysin concentrations was measured, and the cells showed a typical distribution of resistance to hemolysis. 5. As the temperature was lowered lysis was more extensive. Adsorption of the lysin on the cell surface was apparently increased. 6. The resistance of the erythrocytes to lysis increased slightly as the pH was raised from 5.5 to 7.8. 7. Resistance to lysis was independent of the tonicity of the medium and of initial cell volume. The magnitude of the cell surface was probably the determining factor. 8. A marked shrinkage of the erythrocytes was observed in the presence of calcium ions and lysin, but not in the absence of the lysin. 9. Hemolytic resistance curves obtained by the Wilbrandt technique were of the "colloid-osmotic" type. However, there was no evidence of prolytic loss of potassium ions. 10. Hypotonic fragility of the cells was slightly increased in the presence of the lysin. The rate of penetration of thiourea was greatly increased.